Chapter 7

UCLA (1969-1978), Research Support, Government Grants, Assisting Projects, Mammalian "Activity Types," Influences of Light on Medium-Sized Mammals, Optimal light levels

Overview
This chapter opens with a discussion of how I supported my academic research through government grants and 'excess property.' The latter was acquired through the General Services Administration from other entities holding government grants or contracts. Having become expert in the acquisition of such property I was able to become acquainted with and facilitate several large-scale research and service projects, both on and off campus, including observatories in Hawaii and South America.

In 1969 I began to branch out to study the influences of ambient light on the activity and orientation of other small mammals than mice, beginning with least weasels and eastern chipmunks. Light regimes employed included both abrupt changes and simulated twilights. The findings both reinforced the importance of employing simulated twilights in laboratory studies and suggested that traditional studies usually employed light levels far above the optimal ranges for nocturnal rodents and far below them for small diurnal mammals, such as eastern chipmunks. Running usually was highly directional, but the direction could be determined by either the light source or enclosure features.

My studies to that point led me to distinguish between and define two "activity types" characterizing small mammals. The ecological activity type characterizes activity phasing in the wild, whereas the visual activity type can be revealed only by studies in the laboratory. The former type does not necessarily reflect the adaptations of the visual system, but is an expression of complex interactions with many habitat factors. The latter type, on the other hand, primarily reflects adaptations of the visual system (the eye plus all central nervous connections).

The time also was ripe in 1969 to extend our studies to animals of medium size. To this end six carnivores and a monkey were studied in a 4-ft-activity wheel. All animals showed characteristic patterns of running and responses to ambient light. Some were arrhythmic, one primarily nocturnal, while others were diurnal, with a tendency to nap during midday. A monkey was 95% diurnal, highly acrobatic, and most active during dawn and post-dawn hours. High-speed running of a ringtail during early dawn was in a spectacular fast burst. Light level changes during activity periods influenced the arrhythmic animals much more than the diurnal ones.

The above laboratory findings were compared with known behavior in the wild. These findings and earlier ones with small nocturnal mice also have implications for the exhibition of animals in zoological gardens. Contacts with the San Diego zoo, for example led to the use of exercise wheels in several mammal exhibits, while the employment of stimulating artificial dusks and sufficiently dim night light could be very useful to stimulate activity in displays of small nocturnal mammals.

In the same year we also studied roadrunners in 4-ft activity wheels. The wheel on the roof of the Life Science Bldg. was naturalistically shielded with plant material. Weather variables also were recorded. The birds readily accepted the wheel as an outlet for locomotor activity, sometimes treading it, sometimes hopping along, and sometimes propelling it at highest speeds by hopping on and off its axle. Like the mammals, the birds sometimes 'ran' unidirectionally for long periods, being strictly diurnal and most active in predusk hours.

In the early 1970's we studied antelope ground squirrels. One outdoor study occurred during a partial solar eclipse, leading to fortuitously detected correlations between changes in behavior and altered weather variables. In another study we determined the influences of rapid temperature cycles on wheel-running parameters. The animals proved to be unexpectedly sensitive  to temperature. Such studies have major advantages over the use of treadmills.

In 1972 two of my predoctoral students and I began an extensive indoor and outdoor study of carnivores. In a pilot study, 13 animals of 5 species were tested for their volitional control of illumination preferences using the control of ambient illumination techniques of Chap. 6. For 10 of the 13 animals, the active time was greatest at the highest level available to them. Although we have noted that running speed often is correlated with light level for small, non-carnivorous mammals in other types of studies, no consistent effects emerged in these volitional light level preference tests. Further studies showed that correlations do exist for carnivores when light levels are imposed rather than volitional.

In another study we determined the outdoor emergence and retiring times of 10 carnivores relative to sunset and sunrise. Each animal exhibited a correlation between time of initiating activity and the dusk light level. Emergence times relative to sunset were highly consistent for some individuals. Average emergence times varied from 1 to 36 min after sunset. On only 4 occasions did an animal emerge at or after completion of the transition to night, which occurred 35 to 52 minutes after sunset. Emergence times (and some retiring times) usually kept pace with seasonal progressions of sunset and sunrise. These progressions varied seasonally from 14 to 94 sec/day. Retiring times often were long before sunrise, as long as 260 min, and generally were much more variable.

The chapter concludes with the results of intensive studies of the influences of light on the activity and phasing of 42 representatives of 16 species of carnivores, carried out over a period of 6 years. Four regimes were employed: (1) outdoor conditions, including records of meteorological variables; (2) indoor, 24-hr cycles with artificial twilights and unvarying day and night light; (3) stepwise changes in day or night light levels every 30-min during activity periods; and (4) indoor 3-or 4-hr cycles with artificial twilights and constant 'day' and 'night' light.

The findings support earlier conclusions that activity in exercise wheels is an excellent means for assessing the influences of environmental variables on a wide variety of mammals of different sizes and habits in later, unpublished studies also found to be true for birds. Responses to these particular tests may be the best available behavioral guide for assessing the overall state of adaptation of the animals' visual systems. Very likely, adaptability of the carnivore visual system is at the highest level in any terrestrial vertebrate group because of the advantages for predation that are conferred by so called 24-hr vision.

Active time of carnivores at various light levels appears to be the most reliable index of light-level preferences, and the best indicator of the relative degree of visual adaptedness. Changes in running speed may have a more complex origin. In the case of nocturnal mice, speed during artificial twilights is often proportional to the light level. The mice slow down as dusk proceeds and seeing conditions for negotiating the substrate and avoiding obstacles become poorer, and speed up again during dawn as conditions improve. These responses are believed to reflect a genetic adaptation of animals with primarily simplex vision (in this case, only rod cells). The adaptation increases the ability to catch prey and gather plant food, and decreases the chance of being caught by predators.

Results for the carnivores in different tests are compared with those in the wild. The findings can be coordinated by dividing the animals into four groups. The first includes adult ringtails, kinkajous, mongooses, gray foxes, kit foxes, the skunk and genets, all of which appear to be primarily or strictly diurnal or nocturnal. Our findings for 24-hr phasing are in agreement with the field observations. Beyond this, our other tests showed adaptedness or versatility of some of the animals in other conditions.

The second group includes the coatis, grison, and tayras, for which field results conflict. Our tests indicate that these species are adapted best for vision in daylight, but the coatis showed some nocturnal tendencies, and both the grison and tayras appear to have highly versatile vision. The ecological activity types of these species are probably determined mainly by proximity to man-primarily diurnal where unmolested but shifting toward nocturnality near human settlements.

The third group comprises the red fox, arctic fox, and long tailed weasel. As regards activity phasing, these animals are very adaptable in the wild, with seasonal factors having primary influences on, at least, the foxes. Our studies indicate that these animals are adapted best for dim-light vision, but that they also see well in daylight.

Into the last group fall 4 of our 5 juvenile animals, namely, the two gray foxes, the coyote, and the red wolf. Their findings may not be compared with field results unqualifiedly because of possible complicating maturational changes. These four juveniles showed arrhythmic tendencies. Gray foxes, at least, appear to become less arrhythmic as they mature.

The tendency of many animals to be active during dawn and dusk probably hinges upon these being prime times for hunting and food gathering. Twilights are often times of intermediate temperatures. They are the only periods when the activities of many animals overlap. A very influential factor for rodents and small carnivores is the fact that many insects are most active during twilights. Only eight animals failed to show evidence of intensified activity during or proximal to twilights. The remaining 34 had marked to minor activity peaks, which accords with our hypothesis that high values of activity indices usually indicate conditions favorable for activity.

 

Government grants

Throughout the period of my behavior studies at UCLA to 1979 I was supported by either the National Institutes of Mental Health or the National Science Foundation (NSF), or both mostly NSF. Although I decided to forego further extramural fundraising through grant applications sometime in the early 1970's, I had been very generously supported over the years. The funds obtained played a significant role in making possible our detailed, automated studies. Information about only one grant survived, and that happened to be one that was not funded. It survived iin the file of my co-applicant, Dr. H. S. Robert Glaser, who later became a professor at the U. of Giessen (Germany). All other information in a bulky file was discarded when I moved to my new office, years after retirement in 1990.

The joint, unsuccessful application with Bob Glaser, one of my acquaintances at Berkeley, but newly arrived then at UC Riverside, was in 1960 to NSF,. We planned to study the activity of small night lizards (Xantusia vigilis) using a grid of horizontally distributed, sub-sand proximity switches. The title of our rather ambitious $121, 000, 3 year proposal, was "The third eye of lizards, its influence on motor activity."
End Overview

Government excess property

In the late 1960s I became aware of a U.S. Government program administered through the General Services Administration, whereby any entity holding a government contract or research grant became eligible to apply for (and often receive), on a first come first served basis, any non-restricted, excess materials from any other government sponsored activity. The latter included NASA, the Armed Services, aerospace and aircraft-companies, government laboratories, etc. Eventually, after its use or obsolescence, all material could be donated to any educational activity.

Holding government research grants, I was eligible for excess property. At first, I filled our needs by finding available lots of such materials, including needed items, like meters, wire, electronic components, recorders, etc. I soon realized, however, that I could acquire virtually everything needed in our studies through this program. This would relieve me of the never ending need to write reports and new grant applications.

Or I could achieve this without holding a government grant by cooperating with other laboratories holding grants. So I decided to replace an onerous activity with one that was more challenging, exciting, and gratifying.

I would keep on the lookout for needed equipment and supplies for large campus projects, both research (e.g., in the Astronomy Dept.) and service (e.g., in the Theater Arts Dept.), with the option of keeping the leftovers that were of use to us for our studies. I obtained needed expendables in the way of paper, ink, etc., through my yearly modest University Faculty Research Grants for which all faculty were eligible. These were available to me until 1990, when I retired. It was in this way that I largely supported our studies beginning in the early 1970's. To save on shipping and packing expenses, my students and I would rent a University vehicle and make visits to government activities throughout central and southern California. These ranged roughly from San Francisco to San Diego, including virtually every military base and aerospace company; but more of that later.

Aid to, and participation in, other educational projects

By way of introduction, I reproduce a letter written on my behalf, on October 17, 1977, primarily for the Biology Department Chair, by a physicist, Zoltan Lucky, Engineer on the UCLA Tokamak Fusion Energy Project, the campus' largest plasma physics facility.

To whom it may concern: UCLA possesses two of the leading research laboratories in the world in the field of plasma physics. The plasma physics laboratory in Knudsen Hall is the leading laboratory in the study of basic plasmas phenomena in giant plasma chambers, while the Tokamak laboratory in Boelter Hall is the leading laboratory in the study of scaling from small to large Tokamak configurations, in the diagnostics of the plasmas contained therein, and impurity control.

These studies are vital for the development of fusion power, one of the world's leading options for future energy production, and they now are supported vigorously by ERDA funding. The Tokamak laboratory was established only two years ago under the direction of Professor Robert Taylor [a product of UCLA, recently returned (late 1970's) from MIT to head the Tokamak lab], while the plasma physics laboratory has been operating for many years under the direction of Professors B. Fried, A Wong, K MacKenzie, and others.

For the last 5 years, Professor J. Lee Kavanau has played a vital role in facilitating the research of these laboratories through making available large quantities of equipment, raw materials, electronic and hardware components, either by providing them from his own extensive facilities or by searching out and acquiring them for us under the sponsorship of our own research contracts. One cannot overemphasize the financial and temporal importance to our research projects of being able to call upon and acquire from Prof. Kavanau at only a few moments' notice the hundreds of different, often unusual and specialized, components and raw materials that routinely are needed by us. To have had to acquire most of these components from outside sources would have taken, in each instance, weeks and months, and would have caused serious delays in the course of our research.

In many cases we would not have been able to afford to acquire the components in question, both because of insufficient funding at the time and because of minimum order requirements. These considerations apply in greatest force to the Tokamak laboratory, with which Prof. Kavanau has been associated since its inception. To estimate the amount of money and time saved for us by Professor Kavanau is difficult but the former surely runs into the hundreds of thousands of dollars per year and the latter into many weeks or months.

To give some examples of the magnitude of his assistance, in one case he located and acquired for us gratis 35,000 pounds of high voltage, energy storing capacitors worth about $100,000, without which we might have been delayed for months. In another case he located and acquired for us gratis about 40,000 pounds of raw stock in aluminum and hot and cold rolled steel worth $50,000 to $100,000 that have comprised the basic stock for most of our construction projects. He also located and acquired for us and provided from his own stock a large pool of oscilloscopes, oscillators, and other test and measurement equipment that were vital in setting up the Tokamak facility. In still another instance he located for us a 350-ton, 2 megawatt generator which, unfortunately, turned out to supply energy at too high a voltage for our need. He also located large quantities of power cable which have been used in making the power connections to our various power supplies.

In addition to large-scale assistance of this type and our needs for special and unusual components, we routinely call on Prof. Kavanau [or visit my depots, for which they had keys - JLK] 8 or 9 times per month for small and large quantities of run of the mill hardware and electronics.

The above might seem like an exaggeration by Zoltan, but I will explain why it is not. Materials and equipment usually were made available by the facilities from which I acquired them in rather large lots whatever remained at the termination of a contract, etc. In many cases the entire lot had to be acquired from the excessing agency because it was practically infeasible to divide it. In other cases, lots could be divided, but only at additional, sometimes exorbitant, cost to the acquiring party or agency.

For those reasons it was most economical, by far, simply to acquire an entire lot. With about 12 depots scattered about the Life Science Building-stairwells, roof, my five assigned rooms, including two vivarium rooms, several outdoor storage lots, etc. and with several campus projects continually in need of supplies and equipment, including some in engineering, astronomy (including at Caltech), geology, geophysics, and theater arts, storage did not present a problem.

Only in 2002 were my roof depots dismantled and materials disposed of, but 12 years earlier, when I retired, my five rooms were reduced to only my office and experimental room, to make way for new faculty. Then in 2001, I was displaced again to a small but adequate office. The stairwells also were soon emptied.

In connection with the above, theft was more than occasional on the UCLA campus. Concerning the iron and steel stock Zoltan mentioned above, some of the aluminum extrusions were 14-feet long. We stored these raw materials early in 1977 at the Wadsworth VA Hospital storage area, which had a 24-hr guard and guardhouse, a cantilevered gate, and a sign-in, sign-out requirement. Mindful of the risk of theft we piled all the steel stock on top of the more valuable and useful aluminum stock. Despite these precautions, sometime later someone came in with a long bed truck and forklift, presumably having bribed the guard, unloaded all the steel to get at, and make off with, the remaining aluminum, perhaps a few tons.

On another occasion, we stored aluminum plate stock, about 8-ft square and 1-1/2 to 2 inches thick in an engineering lot. For security, we hoisted a multi ton transformer on top of the plates. Nonetheless all was stolen. The theft was witnessed, and the material located afterwards at a surplus dealer's in Fresno. But proof would not have been easy, and the theft went unpunished. On still another occasion I stored miscellaneous small pieces of sheet, bar, and rod titanium stock in a stairwell, and it disappeared in a couple of weeks, being worth several dollars per pound (it cost the government slightly over $12 per pound). But a similar collection of tool steels was left untouched, as its value was much lesser.

In another interesting theft incident, I stored perhaps 1,500 pounds of 2-conductor, stranded 16-guage wire in a stairwell. After several months all of it also was gone, except for one large roll that had taken three men to get down the stairwell stairs. Evidently the thieves, unable to handle the 2 1/2 foot, 250 pound spool, didn't feel it was worthwhile to rewind it onto smaller spools. Much of my material was stored in locked steel cabinets, 6 to 7 feet tall, mostly on the roof of the Life Science Bldg.. Despite the fact that almost all of these materials in cabinets were of little or no use to anyone else, and would have been hard to turn into cash, almost every cabinet was broken into, some with handles ripped off, in the attempt. It is obvious who the people were who were responsible for these thefts, but I point no finger. In this connection, I donated a TV camera, monitor and wiring to the Campus Police Dept. to mount at a strategic location to monitor entering and leaving vehicles, to try to stop the thefts, but to no avail. In fact, I never heard from the police again, afterward,

Regarding the 350-ton generator, which, incidentally was powered by a railroad locomotive's engine, there was considerable excitement for a time after I put a 'freeze' on it, as it could well have been highly desirable. Zoltan and another researcher from the project went up to the Lawrence Berkeley Laboratory to inspect it, only to discover that its output voltage was too high. The high voltage capacitors referred to above weighed at least 200 pounds each and were located at the old McConnell Aircraft facility in Santa Monica, still fully mounted from their prior use. Zoltan and a group from the project had to disassemble them and bring them down by hand. I don't remember how many days it required.

One lot I received contained a 3-foot, cellular construction, fused silica, telescope mirror blank (Fig. 7-1). This eventually found a home at the Carnegie Institution's Las Campanas Observatory in Chile, operated by the Hale Observatories, in use for spectroscopic purposes. While the mirror blank was being held at Caltech, the astronomers (J. W. Boise, J. B. Oke, A. H. Vaughn, and J. A. Westphal) had a visit from a Corning Glass Works representative. By coincidence he had been present at the time when the blank was cast, years earlier.

Acknowledgements of assistance with services, supplies and equipment

I reproduce below some other letters of thanks from several campus and outside projects, and merely excerpt others.

From the Hale Observatories, Horace W. Babcock, Director, whom I had assisted with the construction of his bombsight during the war years at Caltech dated July 4, 1975: I appreciate very much your telephone call of some 3 months ago when you advised me of the availability of a variety of surplus components, material and instruments that could be used to advance the educational and scientific work of the Hale Observatories. As you are well aware, several of our people have visited your department and have taken advantage of the opportunities you have offered. The items you have made available to us from your surplus stocks have expedited a number of research projects. The savings in time and expense have been quite significant.

In particular, the observatories are grateful for the oscilloscopes and for the light weight fused silica mirror blank (Fig. 7-1). This last item will figure importantly in future instrumentation for 2.5-meter telescope of the Las Campanas Observatory in Chile. The quantities of electrical connectors that match equipment and systems on the 200" Hale telescope at Palomar are also proving to be very useful and will result in significant savings to the California Institute of Technology. [In this connection, I also donated several hundred pounds of lens blanks and miscellaneous other items to Keck II in Hawaii.- JLK]

UCLA Theater Arts Department, Professor W.D. Ward, Technical Director, dated July 30, 1976:

On behalf of the students and faculty of the Theater Curriculum I would like to express our deepest appreciation for your continued support during the past year. Your participation and assistance have greatly enhanced our programs and productions, and your contribution of material, energy, talent, and ideas have had a profound effect on the continued operation of many of our theaters, shops, and laboratories.
Your assistance has been largely responsible for several major projects including:

1. The soon to be completed sound control system for the Macgowan Little Theater; a multi channel sound mixer to be utilized by students....Your efforts have resulted in a saving of at least $3,000 in the development and installation of this system. While not all components of the system were completed, 1,796 hr of student utilization were logged on hundreds of projects and over two dozen productions in 1975-1976.
2. The replacement of deteriorating sound monitoring equipment in the Freud Playhouse Theater and the Macgowan 1340 Theater has been initiated due to your assistance in securing the components required for this project. Many hundreds of dollars have been saved and an important project, which would otherwise have not been feasible, has been activated as a result of your efforts.
3. The installation of temperature monitoring and improvements in control logic for the Digital Scenery System; a device for monitoring the position and controlling the movement of electric motor driven spot lines for scenery handling have been made possible by your support. The temperature monitoring device for the variable frequency drive should save on the order of $1,000 per year in repair necessitated by thermal damage. Improved control logic systems should ease system operation and increase safety.
4. The repair and maintenance of many other electronic and electrical devices utilized in our labs and theaters continues as a result of your aid.
   

Each year our productions bring thousands of people to the campus. Many of the productions of the Theater Arts Department have benefited from your support. A partial list includes:

1. Remotely controlled playback of music for Pajama Game, July, 1975.
2. Directional playback of music and sound effects for numerous productions including: Inherit the Wind, October, 1975; You Can't Take It With You, February, 1976; The Crucible, June, 1976; Front Page, July, 1976; and Take Me Along, July, 1976.
3. Assistance in securing scenic materials for the preparation of scenery and properties for Pajama Game; West Side Story, May, 1976; Abe Lincoln, February, 1976; and Take Me Along.
4. Assistance in securing line for lashing portable cables providing power for lighting equipment for all productions, 1975-1976.
   

Your dedication and service to our curriculum are greatly appreciated.

UCLA Department of Surgery/Neurosurgery, Dr. T. Babb, October 21, 1975:

I would like to extend my fullest appreciation for the time and effort you gave toward providing us with electronic supplies needed for continuation of our research projects. As I mentioned to you on my visit to your lab, the supplies provided to us by you were not readily available at local electronic supply houses and/or the cost of such supplies were greater than our limited project funds. In particular, precision resistors available for use in biological amplifiers, high power, high performance transistors for biological stimulators, and a high current D.C. power supply were items which would not have been available to us were it not for your generosity. We will begin to use these new electronic circuits in studies of epilepsy in monkey and man.

Our experimental studies on cerebellar influences on epilepsy in monkeys will be of outstanding quality now because we were not forced to compromise due to lack of funds to purchase precision electronic supplies. In addition, we are no longer way behind schedule in fulfilling the research goals of our NIH contract because the immediate availability of electronic components permitted us to go ahead with design and fabrication of circuits over the summer months, when a skilled engineering student was working for us full time.

The biological stimulator fabricated from precision parts obtained from you will be an important improvement over the present means of electrical stimulation in man. We will have full control over all parameters of pulse delivery, and safe stimulation of man is now assured.
Dr. Crandall and I invite you to visit our Clinical Neurophysiology and Cerebellar Neurophysiology Projects whenever you have the opportunity.

California Institute of Technology, Owens Valley Radio Observatory, Professor A. T. Moffet, May 2, 1975:

Thank you very much for the donation of microwave components, connectors, power supplies, and other items. These will be incorporated into receiving equipment we are now constructing or which we expect to construct within the next year or so and should save the expenditure of several thousand dollars from our NSF Grant.

KCET/Channel 28, James A. Mead, Engineering Supervisor, June 28, 1972.

Thank you very much for your kind donation to the Engineering Department of KCET. I will be calling you soon about some other equipment that your department could possibly donate to us. A. A. Hart, Engineering Manager, May 15, 1975: On behalf of KCET, I would like to thank you for your donation of the Andrews co axial switch and the precision attenuator.

Your generous gift of parts and loan of instruments has enabled the KCET Engineering Department to undertake projects that would probably not be attempted due to budget considerations. Once again, thank you for your generous support/

UCLA School of Engineering and Applied Science, Professor N. C. Luhman, Jr., May 23, 1975:

I would like to take this opportunity to thank you for your generous help in obtaining instrumentation and supplies for our laboratory. On numerous occasions our research program would have been stopped for want of some crucial component had it not been for you.. In these troubled economic times corporations appear to be further cutting back on inventories and your help becomes of increasing importance. In addition to aiding our funded research, you have also made possible the preliminary experiments which formed the nucleus of two pending proposals (NSF and ERDA).

Ralph Waldo Emerson Junior High, Principal R. L. Hawkins, April 13, 1975 for: a long list of shop supplies and equipment.

UCLA Fernald School, Sharon Wirtenberg, SSA Supervisor, June 12, 1975 for: many electronic components, particularly a 3 1000 Z tube and its accompanying transformers gave the students a wonderful opportunity to build and learn electronics in practice and theory.

Los Angeles City Board of Education, W. J. Johnston, Superintendent of Schools, December 21, 1976, for: 2,500 pounds of sheet aluminum and 1,500 feet of stainless steel tubing.

UCLA Electrical Sciences and Engineering, Professor Frank Chen, February 18, 1975, for: supplies and equipment

UCLA Department of Surgery, Professor V. Honrubia, Director of Research, October 7, 1975, for: hardware, electronic components, and materials.

UCLA Department of Geology, Professor C. A. Hall, Chairman, July 18, 1975, for: hard to get electronic parts; precision resistors, capacitors, transformers, wire, cable, integrated circuits, etc.

UCLA Institute of Geophysics and Planetary Physics, K. Olwin, Business Officer, August 15, 1975, for: many items of electronic equipment and components.

California Museum Foundation, S. Yukelson, Instructor, August 7, 1975, for: 25 variable resistors, 50 toggle switches, 35 G.E. #13 bulbs, and 3 voltmeters.

UCLA School of Engineering and Applied Science, Professor H. Buchberg, June 12, 1975, for:

supplies and equipment, including a flat heating element particularly useful in the calibration of our thermoelectric boundary conductance instrument, a pump, reservoir, fittings and tubing that have helped the students develop their test loop for solar collector studies.

I also assisted Professor Holland Ford of the UCLA Astronomy Department with supplies and components enabling students to view telescopic images remotely, through an ingenious television system, from a telescope on the roof of the Engineering Building. Since that time, Ford has gone on the Johns Hopkins University, and [in the1980's and 90's] is much in the news through his association with space telescope projects.

A few sources of the excess property

When it became necessary to vacate my office and adjacent experimental animal behavior laboratory in 2001, and take up office quarters in about one quarter the space in another building, I was forced to dispose of many old records intentionally, and I also accidentally disposed of others. I retained records of some raw stock excess property obtained in bulk for other projects in the years 1972-1978, since it never becomes obsolete, and mainly for inventory purposes. These records usually tell where and when the material was obtained. I list the sources below, together with dates of acquisition and project or facility of origin, in that sequence.

Airesearch Manufacturing Co., Torrance, CA,
9/6/74, NASA, Johnson Space Center, Astronaut Life Support Assembly
6/8/76, NASA Lewis Research Center, HXDA
11/19/77, Air Force Weapons Lab., E Beam Gun
2/13/78, DSA, DCASR, (DCRL CMC)

Brunswick Corp., 1/18/73, Ablative Material

DCASO Aerojet ElectroSystems Co., Azusa, CA, 7/18/74, Contract FO4695 67 C 0034

General Dynamics, Pomona Division, 3/19/74, Standard Missile Competitive Buy

Lawrence Berkeley Laboratory, Berkeley, CA, 9/22/72 and 4/26/74, In House research

Lawrence Livermore Laboratory, 11/15/75 and 12/15/75, In House research

Lockheed California, Burbank, CA,
3/25/74, US Army Lockheed Plant Activity
4/25/74, U. S. Army Lockheed Plant Activity

Lockheed Missiles & Space Co., Sunnyvale, 1/27/75, Trident I OSDP

McDonnel Douglas Astronautics, Huntington Beach, CA, 2/23/76, DAHC 60 68 0 0017

NASA Contract NAS 9 14000, 7/23/77, 9/26/77, Shuttle

Rockwell International, 10/31/77, and 11/16/77, International Airport, B 1 R&D

Rockwell, Rocketdyne Division, Canoga Park, 7/31/73 and 5/6/74, Saturn Engine

Teledyne Ryan Aeronautical, San Diego, 3/24/76, 5/11/76, and 88/15/76, AQM 91, Special Purpose Aircraft

Watkins Johnson Co., Palo Alto, 10/16/73, Multi Cathode Electron Gun TWT

FURTHER PUBLICATIONS DEALING WITH ANIMAL BHAVIOR

A Genus of Small Mammals
In 1969 came another invitation from Science, this time to review the book, Biology of Peromyscus (Rodentia), edited by John A. King. My review (1969;165:182) was accompanied by a very attractive cover (Fig. 7-2) for the 22 Aug. 1969 edition. By coincidence, I had spent a partial sabbatical with Prof. King at Michigan State University, Lansing in 1966. My review began as follows:

An introduction [to the book] by W. Frank Blair sets forth clearly the rationale for this fine work. "The diversity of life is so great that we can never hope to answer all of the questions we might pose for all of the kinds of organisms, so we look to detailed studies of representative taxa for elucidation of the principles governing diversification and maintenance of diversity...."

Branching out to other small mammals
Having obtained the reviewed remarkable results concerning activity and orientational responses of WF mice to light, anxiety was great, and expectations high, to make comparisons by studying larger small mammals. These would include some diurnal representatives, for which comparable prior studies were rudimentary or non-existent. First to be studied, in 1969 were eastern chipmunks, Tamias striatus and least weasels, Mustela rixosa. An 'announcement' paper on the influences of light on their activities appeared in 1969 in Experientia (25:208-209), titled Influences of light on activity of the small mammals, Peromyscus spp., Tamias striatus, and Mustela rixosa. A detailed paper with figures (see below) illustrating the new findings appeared in Ecology in 1969 (50:548-557), titled as below.

Influences of Light On Activity of Small Mammals
This paper was among my four papers on animal behavior mentioned earlier that generated the most reprint interest (over 268 requests). In these papers, it was emphasized that differences in running under various light conditions had the potential to reveal the state of adaptedness of the visual system for day and night activity. Such findings could have a bearing on the evolution of diurnality and nocturnality.

To these ends, the locomotion of the chipmunks and least weasels in activity wheels was studied at various light levels on regimes employing both 54.5 min artificial twilights and abrupt changes between bright daylight and dim night-light. Several properties of their running, and also of the WF mice of earlier studies, show much the same qualitative dependences on light level. All 3 species have a strong tendency to run in only one direction for extended periods. They get their orientational bearings from sightings of nearby objects. Whereas the artificial moon seems to be the preferred bearing for WF mice, other objects in the enclosure seem to be preferred by chipmunks and least weasels.

The least weasels were stimulated to activity by artificial dusk and inhibited by artificial dawn, but not by sudden onset of bright light. The chipmunks, on the other hand, were stimulated to activity by artificial dawn. When the length of the daylight period is comparable to that in the wild, they cease activity several hours (hr) before dusk. An early 'unexpected' dusk or darkness, presented while they are still active, merely slows their running.

These findings, and those with WF mice, reinforce the importance of employing artificial twilights in laboratory studies of the activity and rhythmicity of most animals. Finding least weasels to be 98% nocturnal in light conditions simulating those in the wild suggests that their visual system is still in the process of evolving from a nocturnal to an arrhythmic type, since this animal already is arrhythmic in the wild (habits can change faster than physiology and anatomy)

With bright daylight (330-1,500 ft-c), chipmunk running was highly directional, 99.6-100%, usually toward the light source, and occurred during the day, regardless of whether artificial twilights or abrupt light changes were employed. It continued steadily for 9-10 h, ceasing 4-5 h before dusk or night. However, in dim daylight (only 20-40 ft-c) with abrupt light changes, chipmunks tended to ignore the phase of the light cycle, even running in total darkness (Fig. 7-3), which accords with their adaptations for living in, and fleeing into and through, dark burrows.
Accordingly, neither dim light nor darkness inhibits chipmunk activity, and the results suggest that daylight brighter than 40 ft-c may be necessary to synchronize their activity in phase with the 'daylight' periods of artificial light cycles. Running parameters (rpm, session lengths, etc.) at relatively low light levels showed the same dependence as for nocturnal mice; they were greater the higher the low level for both groups (Fig. 7-3).

The chief light regime for the least weasels employed artificial twilights with bright daylight (18-30 ft-c) and dim night light (0.032-0.13 ft-c). Running was strongly unidirectional and nocturnal (97.6-99.9%). A small amount of activity often occurred for a few minutes after dawn, which otherwise was strongly inhibitory. Without twilights, and with dimmer daylight and nightlight, the animals tended to become arrhythmic, with abrupt presentation of light, unlike dawn, not being inhibitory. Running speed usually peaked markedly during both dusk and dawn (Fig. 7-4) but running tended to be less unidirectional then, particularly during dawn.

Although running usually was highly unidirectional (up to 99%) on a given night, it could be either toward or away from the moon, or even only with respect to enclosure landmarks. With moon direction changed every h, the weasels also reversed running direction every h, the most consistent performance being 96% toward the moon (Fig. 7-5). When the intensity of the moon was altered every 30-min in 3 steps, average rpm, session length, and maximum speed also changed stepwise, being greater the brighter the moon. In total darkness, the animals maintained unidirectional running, in the same directions as before the light was extinguished.

To summarize, the running parameters for the WF mice, eastern chipmunks, and least weasels are greater the brighter the light at low levels. They attain maxima at certain levels and then decline. All three animals run highly unidirectionally, using either the light source or enclosure features for orientation. Like mice, both chipmunks and weasels (Fig. 7-5, the two times running recommenced in 'moonlight') usually warm up to top speed, evidenced best in constant light. Whereas mice and chipmunks tend to run continuously, weasel activity is broken into bouts (Fig. 7-5), the latter correlating with known behavior in the wild.

The light-level activity relationships found here differ from those expected by analogy with the circadian rule (see Fig. 7-6). According to this rule, in constant (unchanging) light the ratio of active time to rest time and the amount of activity are greater the higher the light level for diurnal animals but lower for nocturnals. The reason for the discrepancy between our results and the rule is that the rule is based on studies at traditionally employed intermediate light levels. These are far above the optimum range we found for nocturnal rodents and far below that we found for diurnals (see Fig. 7-6, where the peak for chipmunk activity appears to be somewhere between 20-40 and 330-1300 ft-c) - a consequence of ready access to and use only of light bulbs available for the domestic market. In other words, the rule does not allow for extremals on the activity curves (outside the ranges of bulbs on the domestic market too low for diurnals and too high for nocturnals) but assumes the existence of only a descending limb for nocturnal animals and an ascending limb for diurnal ones.

Reasoning by analogy from the results of these studies, a more general circadian rule can be suggested: the ratio of active time to rest time and the amount of activity of many small animals in constant light are greater the higher the light level within certain ranges but lower above these ranges. Allowance also should be made for the possibility that darkness is 'optimal' for some animals (e.g., the ringtails of Figs. 7-8, lower left, and 7-9). The absolute value of the light level for a given species probably is the major factor determining  whether the late phase of dawn is stimulatory (chipmunks) or inhibitory (mice and weasels), the early phase of dawn having been found to be stimulatory for all animals studied.

Ecological and visual activity types
The animal behavior studies to this point led me to distinguish between and define two "activity types" characterizing diurnal, nocturnal and arrhythmic small mammals, as a working hypothesis. Thus, the ecological activity type is the type characterizing activity phasing in the wild, whereas the visual activity type is the type revealed by studies in the laboratory. In the latter, light levels and the light cycles, simulating natural conditions, are the only variables. The ecological type does not necessarily reflect the adaptations of the visual system, but is an expression of complex interactions with many habitat factors, principally predator pressure and prey availability. The visual type, on the other hand, primarily reflects adaptations of the visual system (the eye plus all central nervous connections).

When the two activity types are the same, I refer to it as "stabilized," and assume that the visual system is well adapted to the animal's current ecological habits. On the other hand, when they differ, I take it as an indication that the visual type represents the most recent stabilized ancestral condition, and that the visual system currently is evolving away from this condition toward one more suited to the present ecological type. Accordingly, determining the visual activity type in the laboratory may reveal the stabilized condition that existed an evolutionary step or two in the past.

For the least weasel, which has a nocturnal visual activity type, and an arrhythmic ecological type, I postulate that the animal had a stabilized recent nocturnal ancestor, and that its retina currently is evolving toward the 24-hr or arrhythmic type. On the other hand, I regard the WF mice as stabilized nocturnals, and eastern chipmunks (and mongooses, see below) as stabilized diurnals, since their activity types are the same in the laboratory and the field.

It is assumed by my working hypothesis that small mammals are highly adaptable and can, in many cases, adopt habits that are far removed from the conditions to which their visual systems are best suited. Indeed, studies of the vertebrate eye suggest, for many mammals, diurnality and nocturnality can appear and disappear over relatively short periods, evolutionarily speaking, as mutations and selective pressures direct. In the past, inferences regarding current and past visual habits, ancestry, and the direction of current evolution, were based primarily on correlations between retinal histology and field habits. Since the visual activity type gives an entirely independent indication of the conditions to which the visual system is adapted, knowledge of visual activity types holds great promise for interpreting retinal histology and for assessing current evolution of the visual system.

Medium-sized mammals and birds
In about 1969, the time was ripe, for comparative studies, to extend the laboratory findings to animals of medium size. An 'announcement' paper on mammals, titled Locomotion and activity phasing of six carnivores and a monkey was published in Experientia (1970;26:1026-1027). A detailed paper of the title immediately below, with graphs and running records, was published in J. of Mammalogy. A paper, "Roadrunners: Activity of Captive Individuals," coauthored with my doctorate student Judy Ramos, appeared in Science (1970;169:780-782).

Locomotion and Activity Phasing of Some Medium-Sized Mammals
Considering the mammals first, comparative laboratory studies of mammalian activity had long been hampered by the lack of a common measure, that is, of a quantitative technique that would be equally suitable for a tiny rodent and a bobcat. While we found that running in an activity wheel was a highly suitable technique for small mammals, we had not tried it with animals larger than squirrels. Accordingly, I decided to test the technique with medium size mammals. I subsequently learned that W.C. Packer had recently shown (1966) that Tasmanian devils would run exercise wheels.

For this purpose I constructed a wheel 1.22 meters (4-ft) in diameter (Fig. 7-7) and employed it with the same experimental procedures, including lighting, recording, programming, etc., as used with small mammals. It was found that a wide range of cat and dog sized mammals readily would run in this wheel. In essence, a suitably large wheel simply provides an endless straight track along which animals can tread unhindered at their chosen gaits. The following results comprise the first comparative findings for the influences of light on the locomotion and activity phasing of medium-sized mammals (J. of Mammalogy (1971;52:386-403).

The animals studied were one female each of the bobcat (Lynx rufus), domestic cat (Felis catus), red fox (Vulpes fulva), ringtail (Bassariscus astutus) (a raccoon like, nocturnal animal), tayra (Tayra barbara), and grison (Grison vittatus), and a male pig-tail macaque monkey (Macaca nemestrina). Animals were acquired, here and in subsequent studies, through licensed dealers or trading with zoos. Except for the ringtail and grison, all animals were obtained as young and raised to young adulthood.

Animals ranged in weight from 1 kilogram (ringtail) to 6.5 kilograms (bobcat). The light cycle generally consisted of 12 hr of bright light (up to 320 ft-c), 10 hr of dim light (up to 1 ft-c), and 1-hr transitional of simulated dusks and dawns (at constant color temperature). The times of daily feeding of diets were selected to minimize interference with activity. Periods of individual study ranged up to 70 days.
Both the bobcat and domestic cat were arrhythmic, with most of their activity occurring at night, but with pronounced peaking in running speed during twilights (Fig. 7-8, upper left). The customary gait was a 'deliberate' walk but galloping occurred regularly, particularly during twilights. Activity was in bouts of 10-30-min separated by much longer periods of rest.

The red fox was nocturnal, at first, but sporadic daytime activity occurred late in the study. Activity was bout like, with speed peaking during twilights (Fig. 7-8, upper right). For the most part, the animal trotted, with frequent short periods of galloping. The ringtail was strictly nocturnal, being fairly rigidly bound by light conditions. It trotted more or less continuously all night, but galloped occasionally, particularly during twilights, most markedly and at highest speed during dawn (Fig, 7-8, lower left) On the basis of amount of activity per unit time, all four animals were most active during twilights.

The 3 tropical animals were diurnal and tended to nap during midday (Fig. 7-8). The monkey (95% diurnal) was most active during dawn and post-dawn hours (not well illustrated in sample record). It alternately walked on all fours and performed various acrobatics. The grison's (Hurone) activity was essentially bimodal, since it never missed its midday siesta. The tayra (Cabeza de Viejo) often was active more or less continuously but sometimes napped during midday. The gait of both the grison and the tayra was mostly a walk. Activity of the tayra was lesser during twilights but very low for the grison (Fig. 7-8, bottom center and right). The gradual changes in running speed with changes in twilight light level that occur with other small mammals did not occur.

The high speed running of the ringtail during early dawn was the most spectacular seen with any animal (Fig. 7-8. bottom left). Alternate dawns and dusks also markedly affected it. On the first night it ceased activity on each of the four dawns, was inactive during the four following 30-min daylight periods, and became active again during each of the four following dusks and 30-min nighttime periods.
light levels during activity period influenced the arrhythmic and nocturnal animals much more than the diurnal ones. Thus, running parameters for the cats, fox and ringtail (100% nocturnal) depended upon the light level during the night, with greatest activity or fastest treading during twilights. The ringtail gave marked responses to 30-min alternations between darkness and 0.012 ft-c, being 71% more active and running fastest in darkness (Fig. 7-9). On the other hand, the diurnal animals paid little attention to temporary changes in the daytime light level, even a drop to total darkness. Like the small mammals of our earlier studies, all 7 animals showed strong tendencies to tread unidirectionally for long periods.

Laboratory studies of the influences of light on activity phasing have the crucial advantage over field studies that all other environmental variable can be kept constant. The light regime, then, is the chief external factor influencing activity phasing. If this regime fairly approximates natural light conditions, the phasing probably gives a good indication of its visual activity type. For example, if an animal is nocturnal in the laboratory, its visual system probably is adapted best for dim-light vision.

In the past, the chief behavioral guide for interpreting the anatomy of the visual system has been the activity phasing in the field. But this phasing often is not a reliable index; it is an expression of complex interactions of the organism with many habitat factors, including light, predator pressure, food availability, latitude, and season. In this connection, mammals are highly adaptable and often can adopt habits for which their visual system is not best suited. Indeed, studies of the vertebrate eye suggest that diurnality and nocturnality can appear and disappear over relatively short periods, evolutionarily speaking, as mutations and selective pressures direct.

Since only one member of each species was tested, results remain tentative. The activity phasing of four species, the bobcat, red fox, ringtail, and monkey did not differ significantly from that presumed from field observations. Reports for tayras are in conflict. Some workers report them to be primarily nocturnal, others chiefly or solely diurnal. Our diurnal finding may help to resolve the conflict; tayras may be diurnal where unmolested, but tend to become nocturnal where disturbed by man..

The grison is said to be chiefly diurnal but nocturnal activity also has been reported. Since our animal responded like the tayra in most tests, and since both are tropical mustelids (weasel family) with many similarities, the same comments likely apply to the visual systems and activity phasing of both. The findings for the domestic cat suggest that a few thousand years of domestication have not altered a basically arrhythmic ancestral activity type.

Except for the domestic cat there exists little or no direct knowledge of the retinal histology of the animals studied. Until both the activity phasing in the laboratory and the detailed histology of the retinal cells and their interconnections (degrees of summation, etc.) are at hand for a diverse representation of mammals, it would be premature to draw conclusions regarding relationships between the two lines of evidence.
The avid treading of wheels by cat-and dog-sized mammals suggest a new approach to their care and exhibition in zoos. First, a suitable large wheel may offer a more desirable or efficient outlet for activity than the conventional zoo enclosure. Second, exhibits of mammals walking, trotting, galloping, performing acrobatics and competing for the use of wheels probably would interest observers more than one of their lying prone, sleeping, or occasionally pacing to and fro. The same approach also might succeed with larger mammals.

In fact, after I gave a lecture at the San Diego Zoo, including movies of animals running in wheels (which were mistakenly shown in slow motion), the Zoo's policy was altered. Previously, the renowned Director, Charles R. Schroeder D.V.M., opposed the use of non-natural 'props' in animal exhibits. Afterwards, running wheels were installed in some monkey exhibits (wheels angled at 45° (Fig. 7-10) with monkeys constantly jumping on and off during its rotation) and the medium (foxes) and large (fossas) mammal exhibits, with both foxes and fossas cooperating in their use (Figs. 7-11-12).

The caption to the picture in my article, Mammalian Activity (Zoonooz July 1970 pp. 4-7) read as follows:

As a result of Professor Kavanau's studies, a four-foot exercise wheel has been installed in the enclosure of the Fossa Cryptoprocta ferox, at the San Diego Zoo. This primitive carnivore of Madagascar is a short legged long bodied creature from five to six feet long of which almost half is tail. The two fossas run in the wheel frequently, at times together. The vinyl covered wire mesh gives the fossas a smooth-cushioned running surface. This "pilot" wheel will be tested for a short period and then it is planned to provide wheels for others, including wolverines and the otter civets.

When I last checked (Feb., 2006) with mammal curator, Dr. Curby Simmerson, a running wheel was being employed in a coati exhibit.

Titles of newspaper articles on medium-sized mammals:
"Cats' food  for thought: they prefer light"
"Lab animals find school, like it"
"Lab animals are 'big wheels'"
"Night animals prefer light, tests indicate"
"Predators will hunt anytime"
"Night animals actually prefer daylight"
"Hunting habits of night predators probed at UCLA

Roadrunners: Activity of Captive Individuals
The roadrunner (a non-parasitic cuckoo) or chaparral cock, Geococcyx californianus, inhabits deserts, chaparral, and arid grasslands in Southwestern North America. It is active during the day, preying on lizards, rodents, snakes, spiders, and insects; various fruits and seeds also are in the diet. It can run at up to 8 m/sec (18 mph) for short distances. Little is known of the pattern of distribution of its activity, but reduced activity during hot midday hours has been noted in the Mohave and Sonoran deserts.

Judy Ramos and I studied two hand raised birds, weighing roughly 340 grams each, outdoors for 3-4 weeks each during June and July, 1969 (Science 1970;169:780-782). The birds had access to activity wheels 3 ft in diameter adjacent to their nest cage. The wheel was similar to that in Fig. 7-7 but smaller and honeycombed to permit vision in all directions. The cage and wheel were surrounded by wire mesh covered on the sides and top by dense arrangements of artificial plants, giving cover and a semi natural setting (Fig. 7-13). The assembly was located on the roof of the Life Science Building at UCLA. Food was provided once daily on an irregular daytime schedule that interfered minimally with activity.

Temperature, relative humidity, light intensity, time of raining, and time, speed, and direction of running were monitored continuously. With this arrangement it was possible to establish the roadrunners' responses to fairly natural light and weather conditions. During the following July to September the birds were studied indoors in a similar arrangement (Fig. 7-7) but with artificial lighting and without plant cover, including 1-hr simulated twilights, as with the small and medium-sized mammals, already described. Indoor bright light for activity periods was at 300 ft-c; indoor dim light at night was 0.0002 ft-c.

The birds readily accepted an activity wheel as an outlet for locomotor activity (Fig. 7-14), sometimes treading it, sometimes hopping along in it, and sometimes propelling the wheel at highest speeds by hopping on and off its axle (Fig. 7-14, inset). Like the mammals studied, both birds sometimes 'ran' in one direction for long periods. They were strictly diurnal and tended to be most active per unit of time in the predusk hours.
Outdoor activity tended to peak around noon (Fig. 7-15, left); indoors it increased gradually during the early morning hours but remained fairly constant from 9:00 a.m. to 3:00 p.m. (Fig. 7-15, right). There was less activity on partly overcast days than on clear days. Dim light and darkness were strongly inhibitory, even when presented during activity periods; bright light was stimulatory, even when presented during the night. On tests with alternating twilights, activity was confined exclusively to the last quarter of dawn (16%), daylight (57%), and first half of dusk (27%), in essence occurring only in fairly bright light.

The tendency of the activity parameters to peak before sunset may be indicative of enhanced late activity in the field, possibly related to heavy predation on insects. The low level of early morning activity correlates with the known propensity of roadrunners to sunbathe at this time. At the least, these findings suggest that light conditions are highly restrictive for roadrunners, and that even sleeping birds remain "aware" of external light conditions. These findings appeared to open the way for comparative studies of the influences of environmental variables on the activity of other birds.

Twenty years later, I was repeating the whole range of experimental studies of small mammals, but with small parrots, and other day active species. Aside from the finding that avian activity could be turned on and off at will, using bright light and darkness, all studies showed the birds to be the equals of the mammals in all tested measures of learning.

Studies of antelope ground squirrel activity
Wild animals adjust to changing conditions in their habitats by both physiological and behavioral means. Working within the physiological framework of the species, suitable behavioral responses sometimes permit the exploitation of niches under severe environmental conditions. Such interactions play a critical role in the life of the antelope ground squirrel, Ammospermophilus leucurus, a diurnal inhabitant of the deserts of the southwestern United States and northern Mexico.

In the early 1970's, my doctoral student, Carl Rischer, and I were studying the preferences of 4 mature individuals, trapped from the Mojave desert, California. We investigated the influences of both temperature (Ecology 1972;53:158-164) and light level (Oecologia 1972;8:391-399), which included an outdoor location, during which there occurred a partial solar eclipse (Bollettino di Zoologia 1972;40:217-221). The titles of these three papers are given in the headings below.

Ground Squirrel Behavior During a Partial Solar Eclipse
Many observations of the behavior of animals during solar eclipses have revealed that the dimming phase often leads to activity appropriate to dusk, while during the brightening phase, responses appropriate to dawn often occur. A squirrel's activity parameters during a partial solar eclipse are influenced by multiple ecological variables, most notably light, temperature, and humidity (our measured variable was relative humidity, which varies with temperature). The influences of each variable may be confounded if all are varying at once.

One advantage of laboratory studies, of course, is that the individual influences of the variables can often be dissected by holding all but one constant. All three variables, as well as time, speed, and direction of running in a 1-ft diameter exercise wheel (Figs. 2.11 & 2-12) were being monitored on the day of the partial solar eclipse, with the results shown in Fig. 7-16. The ground squirrel being studied on that day was in naturalistically shielded outdoor roof surroundings (Fig. 7-13) for a week before and after the partial eclipse. Despite the possible confounding of variables, some clear cut results emerged from measurements of activity parameters. The locomotor activity was markedly affected.

Compared to the days a week before and after the eclipse, activity during the first 5 h of the eclipse day was essentially normal (Fig. 7-17); it usually began about 2 h after sunrise and ceased about 3 h before sunset. With the onset of the eclipse, session lengths increased to over three times normal, and active time to as much as 1.8 times normal. With the continuation and completion of the eclipse, these indices continued at levels far above normal, attaining maxima of five times normal for session lengths and 3.5 times normal for active time (Fig. 7-17). But even at 2 h following the eclipse, the indices remained at high levels, with the time active attaining as much as 5.7 times normal. Additionally, some bursts of much higher running speeds over twice normal (over 170 rpm)-occurred during the phase of declining light level (Fig. 7-16; from about 10,000 ft-c to 4,000 ft-c).

It is known from these studies and others that antelope ground squirrels rarely are active during twilight periods. In view of that fact, and the fact that the eclipse was only partial, it is not surprising that our squirrel did not retire to the nest during its dimming phase. Possibly antelope ground squirrels observed in the wild would fall into the same categories as several other animals that do not show obvious qualitative changes in behavior during eclipses.

The quantitative changes in activity that we observed probably were mostly responses to the occurrence during midday of sustained relatively rapid changes in light level, that normally occur only very early or very late in the day. Although these animals usually are inactive during twilights, it is tempting to suggest that these responses reflect the retention of residual twilight responses of their nocturnal ancestors. Minor influences of accompanying changes in temperature (of about 5°C; see below) and relative humidity cannot be ruled out. Though based on only a single animal, the results suggest that an eclipse can induce more complex behavior than mere retiring and emerging responses.

Influences of Ambient Temperature On Ground Squirrel Activity
An indoor study of 4 squirrels subject to relatively abrupt temperature cycles (requiring equipment for rapid transfer of large volumes of air) revealed a possibly important avenue for their regulation of body temperature. The squirrels were exposed to temperature cycles of various amplitudes with upper limits from 28° to 37° C. By monitoring properties of their free running performances in activity wheels (Fig. 7-18), sensitive behavioral responses to the temperature changes were detected. The time spent running, the average duration of running bouts, and the speed of running all decreased with increasing temperature, the first two properties much more than the third. In one test, the time spent running decreased over 11% per degree C. rise of temperature; in another, the duration of running bouts decreased over 8% per degree C. rise.
For studying body temperature regulation, these studies have major advantages over treadmill approaches, in which the animals are forced to run continuously at a fixed speed. First, both behavioral and physiological responses can be determined, which is crucial when animals adjust to temperature changes chiefly by behavioral means. This advantage is emphasized by our finding that four properties of locomotion change with temperature. Second, a more accurate picture of the interactions between temperature regulating responses can be obtained. Third, performance changes closely related in time probably are more reliable than those determined from relatively brief periods of activity of fasted animals on different days. Fourth, the technique can detect subtle and complex responses.

The behavioral responses detected by us were undetected in previous studies because the animals either were unable to run or were forced to run continuously at fixed speeds. Of the locomotor indices measured by us, all except maximum speed showed marked and fairly consistent changes. The higher the temperature, the lower the time active, with the decrement per degree rise showing a clear trend toward greater magnitude for excursions into and above the animals' core temperature range. This finding is consistent with the expectation that activity must be curtailed increasingly at high temperatures if heat stress is to be avoided.

Individual differences in activity between the different animals were of considerable interest. These differences, though great, tended to be compensatory. Low speeds usually accompanied long session lengths and lengthy activity. Accordingly, the differences appear to be partly indicative of variations in the way different individuals regulate their body temperature by locomotor means.

Optimal Illumination for Ground Squirrel Activity
A paper of the above title by my student Carl Rischer and me appeared in 1972 in Oecologia (8:391-399). There had been no systematic effort to pinpoint the optimal light level (or color temperature) for the activity of any diurnal animal. The study described here was a first step in this direction, using the same 4 mature antelope ground squirrels of the above study. Locomotor activity was monitored indoors in the same activity wheel enclosures used in previous studies with small mammals. The standard light schedule consisted of 10 hr of darkness, 1-hr each of artificial twilights, and 12 hr of daytime test light. Tested light levels ranged from 0.11 to 3000 ft-c, and color temperatures from 1950° to 2860°K.

All 4 animals generally were quite active, usually ran for a total of 4 to 6 h/day, and often ran with high directional consistency. In some cases, almost continuous activity lasted for as long as 10 hr. Although changes in running parameters with light level often were evident from inspection of the running records, the correlations were not as striking as those found for eastern chipmunks, described above (Fig. 7-6). Unlike the chipmunks, the ground squirrels did not begin running during dawn, but like them, they also ceased before dusk. The ground squirrel records (not included) are very similar to the chipmunk running records at various light levels (Fig. 7-6), but more complex.

We were able to draw several general conclusions from these exploratory tests. Time spent running, speed of running, and length of non-stop running sessions are sensitive to ambient light. Maxima appear to exist for all of them, but not in the same ranges. The time spent running showed the greatest dependence and appeared to peak between 130 and 1,700 ft-c, the latter value corresponding roughly to light conditions attained within 30-min after natural sunrise and before sunset. Running speed was influenced the least but in the most highly consistent manner, appearing to peak between 260 and 1,700 ft-c. These peaks for both time active and speed are at values that are substantially below the light levels that the animals encounter in the wild (up to 13,000 ft-c). Session lengths were quite variable and showed the most complex changes with light level.

Both light level and color temperature appear to influence locomotor activity. As with the influences of temperature, there were large individual differences in various aspects of the responses to changes in light level. The question of whether 'optimal' light conditions exist for antelope ground squirrel activity, even only locomotor activity, may have to be rephrased into several questions: in what light conditions (1) are they most active; (2) do they run the fastest; and (3) do they run for the longest non stop periods?

For unambiguous results, it will be necessary to test the influences of light level on these animals at constant color temperatures, and the influences of color temperature at constant light levels. The precise sequences in which certain light levels are presented also may have to be taken into account, because each 30-min exposure of one of our squirrels to darkness markedly inhibited its activity in the following 30 min.

light-level Preferences of Carnivores
The most reliable behavioral guide to the overall state of adaptation of an animal's visual system probably is the animal's ambient light-level preference. Determining these preferences in the field usually is not possible, for time of activity in the wild also is influenced by many other factors. For this reason, my doctoral students, Judy Ramos, Roy Havenhill, and I adopted a laboratory approach (see earlier discussion under Medium-sized mammals and birds) to determine the light-level preferences of carnivores. The findings appeared in Behaviour (1973;46:279-299) as the second paper in the series on "Compulsory Regime and Control of Environment in Animal Behaviour," under the above heading as subtitle.

Animals studied included 2 adult least weasels (Mustela rixosa), 2 adult longtailed weasels (Mustela frenata), 3 young adult genets (Genetta genetta), 3 adult ringtails (Bassariscus astutus), 2 young adult gray foxes (Urocyon cinereoargenteus), and one young adult tayra (Tayra barbara). The animals were fed daily zoo diet rations, with minimal disturbance. The experimental program was the same as for WF mice described in Chap. 6 under "Control of ambient illumination," using the regime of complete control. On this program, 2 microswitches on one side of the enclosure stepped the lights one level higher, while 2 switches on the other side stepped them one level lower. The light levels at the bottoms of the wheels ranged from darkness to 95 ft-c.

The running wheels were of similar design to those used with WF mice (Figs. 2.11, 12), except they were of twice the diameter (61 cm) and with interchangeable nest boxes of appropriate size (Fig. 7-19). The enclosures were housed in individual light-proof, sound-proof, constant-temperature cabinets, with an external background of high-and low-pitched sound-masking noises (largely 'white' noise). The cabinets were located in an air-conditioned room. Strip heaters compensated for changes in dissipated heat as different wattage lamps came into use at different light levels.

Our experimental procedure was to allow each animal initially whatever period was required for learning and adapting to the light control program and the general experimental situation. After this period, they were studied for 2-4 weeks. Adaptation and learning were considered to have been completed when an animal's locomotor activity and light selection performance attained relatively stable qualitative and quantitative patterns from day to day. The behavior of the #1 genet did not stabilize, even after 17 days.

Level changes and active times
The animals altered the light level many times per day, the number varying from 27 for a ringtail to 378 for a least weasel. This compared to 101-172 for WF mice in an earlier study. As with the mice, the weasels frequently crossed from one side of the wheel to the other, rapidly stepping the light level in one direction and then in the other, usually spending little time at intermediate levels. As there was no center pane in the 61-cm wheel, the larger animals needed merely turn around to access switches on one side or the other.

light-level selectivity
For 10 of the 13 animals, the active time was greatest at the highest level available to them (15, 30, 50, or 95 ft-c; Fig. 7-20). The most extreme active time preferences for the highest levels were shown by a long-tailed weasel (82%) and ringtail (72%) (Fig. 7-20; second from left at top and extreme left at bottom, respectively). In 3 of the 10 cases, the time was divided almost equally between the two highest levels. Of the remaining two animals, a least weasel and genet peaked moderately at the second brightest level. One ringtail, although spending the most time at the brightest level (14%), gave an almost flat time distribution (second from left at bottom) . This animal served as a partial control (selections essentially random), since it was found to be essentially blind in other tests (having a light sense but no visual discrimination or acuity, caused by cataracts).

The animals that showed the most marked preferences for bright light spent very little time in darkness and only infrequently visited darkness. Thus, one genet visited none of the 3 lowest levels, one ringtail visited darkness only once, another visited it only 6 times, and a longtailed weasel visited it only 4 times. This does not necessarily imply a lack of experience of these individuals at the low levels or darkness, for these levels were visited during periods of adaptation and learning.

Running speed
Although we have noted that running speed often is correlated with light level for small, non-carnivorous mammals in other types of studies, no consistent effects emerged in these volitional light-level preference tests of carnivores. As will emerge in studies reviewed below, correlations do exist for carnivores when light levels are imposed rather than volitional.

Significance of results
As a working hypothesis we suggested that the preference of our carnivores for light in the range of 1 to 95 ft-c depends upon one or more aspects of their vision - such as color, contrast, pattern, and intensity discrimination - being much improved in this range compared to that in dimmer light. On the other hand, all but one of the same animals were found to be primarily nocturnal in an independent study of activity phasing (see below). Accordingly, it appears possible than one or more of the discriminations mentioned above is most sought after when the animals can alternate between conditions in which the discrimination is alternately good and poor.

The animals often continued to press the levers controlling the light level after the corresponding extreme level had been attained. The relative numbers of these "false steps" on the 'on' levers and 'off' levers suggest that, of the two means available, the animals tended to seek additional environmental modification using the means (the 'on' levers) that yielded the preferred conditions. In addition, the animals that showed the most marked preferences for bright light also were the ones with the lowest rates of "false ons," suggesting that less motivation existed to seek change from highly preferred conditions than from less preferred ones.

Light Preferences of Young Foxes (Urocyon cinereoargenteus)
The two gray foxes were the only young animals studied that are included in the above group. Additional findings for them appeared under the above title in the Zeitschrift fur Tierpsychologie (1972;31:404-409). Four week old sibling pups (male and female) were raised for 5 weeks after capture before being studied, with their light-level preferences having been obtained before and after about 14 weeks. Both pups adapted to the experimental situation by the third day. This included learning the light control program, learning to run the wheel, and attaining stable day to day behavior.

These two foxes were the only young carnivores studied, and also the only ones that were found to exhibit an abrupt change in volitional light-level preferences after a long period of adapted behavior. Up to the age of about 14 weeks, the male preferred low light levels, while the female preferred both low light levels and the brightest light attainable (30 ft-c.). After 14 weeks of age, both preferred the brightest level. This latter preference probably is typical of adult gray foxes. The abrupt change in preferences of the female at about 14 weeks may be attributable to the continuation of neurobehavioral maturation processes.

Twilights and the Onset and Cessation of Carnivore Activity
The morning and evening twilights are believed to serve many animals as Zeitgebers (used for setting their biological clocks) and also may be used as reference periods for detecting seasonal changes in day length. A variety of animals are known to customarily begin or cease activity during or near dawn or dusk. Studies of these habits in the wild are highly limited because of the scarcity, secretiveness, and solitary behavior of many medium-sized carnivores. In this study, in a paper with the above title, Judy Ramos and I published the first systematic quantitative data on the outdoor emergence and retiring times of carnivores relative to sunset and sunrise (J. Wildlife Management 1972;36:653-657).
Three genets (Genetta genetta), 3 kinkajous (Potos flavus), and 4 ringtails (Bassariscus astutus) were studied for from 16 to 29 days, at times throughout the year, under naturalistic shielding (see Fig. 7-13) on the roof of the UCLA Life Science Building. In addition to regular animal rooms we had available to us 5 spacious dog runs (4x6x16 ft), also on the roof. The 10 young adult to adult animals were fed zoo diets at various times during daylight, with no noticeable influence of the feeding schedule on their activity patterns. They took readily to running a 122-cm diameter wheel, and exhibited stable activity patterns after 2-6 days. Temperature, wind speed, light level, time of raining, and time, speed, and direction of running were monitored continuously on a strip chart recorder.

Each animal exhibited a correlation between time of initiating activity and dusk light level (Fig. 7-21). The average emergence times varied from 1 to 36 min after sunset, corresponding to light levels of 30 to 0.01-ft-c. On only 4 occasions did an animal emerge at or after completion of the transition to night, which occurred 35 to 52 minutes after sunset. Emergence times relative to sunset were highly consistent for some individuals. For example, the mean absolute deviations of these times for two ringtails, one kinkajou, and one genet, were only 4.6, 3.6, 4.1, and 4.2 minutes respectively. The emergence times (and some retiring times) usually kept pace with the seasonal progressions of sunset and sunrise, which varied from 14 to 94 sec/day during the seasons. Retiring times often were long before sunrise-as long as 260 min-and generally were much more variable.

The strong influences of one or both twilights on the phasing of these species may be correlated with a group of common attributes. All 3 species are relatively small (1 to 3 kg), all are strictly nocturnal and have very secretive habits, all feed on small vertebrates, arthropods, and fruits, and all are preyed on by other animals. None of the other carnivores studied lacking this combination of characteristics showed such pronounced phasing relative to twilights.

Because twilights are periods of intense activity for many animals, the activities of genets, kinkajous, and ringtails during dusk and dawn would enable them to hunt at times of intense activity of their prey. There would be relatively good visibility compared to that at night, and the relatively dim light would provide partial protective cover. For these reasons it would be adaptive for them to emerge during dusk and retire before sunrise.

Our results suggest that rain and overcast conditions were partly responsible for the relatively high mean deviations of the emergence times of one genet and one ringtail. Rain also influenced their retiring times. The likelihood that the findings give a valid picture of the isolated influences of twilights-despite variable weather-is strengthened by the results of indoor studies of the same individuals (see next section). When exposed to light cycles with 1-hr artificial twilights in otherwise constant conditions, the behavior of most of the animals was similar to that displayed outdoors.

Influences of Light on Activity and Phasing of Carnivores
A lengthy paper of the above title appeared in the American Naturalist (1975;109:391-418) and represented a summation of our findings with 42 individual carnivores of 16 species over a period of 6 years. Experimental conditions and enclosure features, having already been treated in the foregoing, are not repeated, except to recall that ambient light level, temperature, time of raining, and wind speed were recorded in outdoor studies (see Figs. 7-22, 23).

Influences of light on the locomotor activity and phasing of carnivores were studied on four light regimes employing natural or artificial twilights: (1) outdoor conditions with corresponding records of environmental variables; (2) indoor, 24-hr artificial light cycles with unvarying day and night light, or (3) with stepwise changes in day and night light every 30-min during the activity period; and (4) indoor 3-or 4-hr cycles with constant 'day' and 'night' light. Twilights were simulated in indoor 24-hr cycles. Responses to such tests may be the best available behavioral guide for assessing the overall state of adaptation of the animals' visual systems.

The phasing and light-level preferences of carnivores are difficult to study. These animals are usually highly adaptable and secretive and usually need to be fed daily; in some cases the taking of a big meal markedly influences subsequent activity. Practical limitations prevented us from studying control groups as regards age, sex, origin, history, etc., providing unsympathetic reviewers with much ammunition. However, for most species our results remain the only existing findings on the influences of light on captive carnivores. The findings suggest the existence of a great range of individual and species differences. Because of difficulties in specimen acquisition, a behavioral study of carnivores of this magnitude and scope probably will never again be possible. For this reason and their inherent interest, all the running records obtained are reproduced here and results are described in some detail.

Adaptability of the carnivore visual system may be at the highest level in any vertebrate group because of the adaptive advantages for predation that are conferred by so-called 24-hr vision. It follows that most carnivores would be expected to have duplex retinas (that is, to possess both rod and cone receptor cells). This probably accounts for the fact that the activity indices of our animals frequently did not show sharp and consistent dependences on light level. Unfortunately, nothing is known of the retinal histology of any of the animals studied. However, the retinas of foxes should be very similar to those of the domestic dog, in which cones (adapted for vision in bright light) number about 5% of the receptor cells.

Interpretations of changes in activity indices
Active time appears to be the most reliable index of light-level preferences. When an animal's activity is influenced significantly by ambient light, the relative amount of time active at different levels would appear to be the best indicator of the relative degree of overall visual adaptedness at those levels.

Changes in speed of locomotion may have a more complex origin. For example, the running speed of captive nocturnal mice during artificial twilights is often proportional to the light level, being greatest when activity commences during mid dusk and ceases during mid dawn. The mice slow down as dusk proceeds and speed up again during dawn. These responses are believed to reflect a genetically established adaptation of animals with primarily simplex vision (in this case, rods only) that increases the ability to catch prey and gather plant food, and decreases the chance of being caught by predators.

In other words, the progressive changes in running speed of the mice during twilights are thought to be an inherited response that had its origin in individuals that moved as fast as "navigational safety" allowed in prevailing light conditions; the brighter the dim light (up to a point), the better were the seeing conditions for negotiating the substrate and avoiding obstacles (though not necessarily for other discriminations) and the faster the rodents moved. Quality of visual discriminations involved in surefootedness and obstacle avoidance apparently is also the dominant factor influencing changes in the rate of movement of certain diurnal rodents in changing dim light (see, also, above reference to my Zoonooz article[1975, July, pp.:4-7], "The Race through Twilights).

Ringtails and kinkajous are believed to be strictly nocturnal in the wild. Our outdoor (Figs. 7-22, 7-23 & 7-24, upper center) and indoor 24-hr phasing results (Fig. 7-23) are in agreement with the field observations. The 3-and 4-hr cycles of alternating twilights (Fig. 7-25) uncovered marked individual differences. On the whole our findings for both species are consistent with a stabilized nocturnal activity type (that is the visual system is adapted to the field behavior). The individual differences found with these and some other carnivores would provide a broad substratum of differences upon which natural selection could act.

According to some workers, coatis (coatimundis, Nasua narica) are almost entirely diurnal in the field; according to others, they are active day and night. One worker found them to be nocturnal during the mating season. Although our studies revealed a primarily diurnal activity type (Figs. 7-23 & 7-25), there were some nocturnal tendencies. Apparently the visual system of coatis is best adapted for a diurnal existence but is also well suited for dim light (their primary prey of small, leaf litter animals are primarily diurnal).

Genets (Genetta genetta) are said to be nocturnal and highly secretive in the wild. All our tests (Figs. 7-24, 7-25 & 7-26) indicated a strongly nocturnal visual activity type. In fact, the generally high level of activity of these animals in total darkness suggests a high degree of development of, and dependence on, other senses than vision.

Small Indian mongooses (Herpestes auropunctatus) are diurnal in the field, with activity tending to be greatest during midday. Our specimens were 100% diurnal and most active from 10:00 a.m. to 4:00 p.m. (Fig. 7-24). Other tests (Fig. 7-26) strongly suggested that vision was best in bright light. A reprint sent to Prof. David W. Nellis, the well known wildlife biologist, elicited the reply, "Thanks for the article. Your findings are certainly supported by my field observations on mongooses."

While gray foxes (Urocyon cinereoargenteus) in the field are believed to be primarily nocturnal, they are also known to hunt by day. Our adults were strongly nocturnal on 24-hr cycles. Other tests showed almost no influence of light level above 0.01-ft-c (50% of full moon), but a sharp drop in activity indices below this value. Accordingly, vision of gray foxes would appear to be well suited for both day and night activity, but there appear to be limitations to their vision in dim light.

Red foxes (Vulpes fulva) in the field appear to be more or less arrhythmic; most of the activity is during the night and twilights, but there are variations that depend on season, latitude, and proximity to humans. Red foxes in Wisconsin tend to be more diurnal in winter than in other seasons, with activity peaks corresponding to peaks in prey activity. Western European red foxes are mostly nocturnal near human habitations but are frequently seen by day in uninhabited areas, Our red foxes were primarily (over 99%) nocturnal (Fig. 7-24, with evident warm ups initiating each bout), but daytime activity reached as high as 10%. On the whole the tests suggest a visual system best adapted for dim light but also well suited for bright light.

Kit foxes (Vulpes macrotis) appear to forage almost entirely at night, preying upon the nocturnal jackrabbits and kangaroo rats, and confine their daytime activities to areas near the den. Our two males were essentially nocturnal with large twilight components (Figs. 7-25 & 7-26). Daytime activity for the female amounted to 37% in outdoor studies and 8% indoors. Taken together, the tests show that, although the kit fox is not inhibited in bright light, it probably sees best in dim light.

Arctic foxes (Alopex lagopus) appear to be arrhythmic in the wild, consistent with the tremendous extremes of day length to which they are exposed. Our animal was nocturnal on 24-hr cycles (Fig. 7-24, lower left) but 4 times as active by day as by night on 3-hr cycles. Neither bright light nor darkness was inhibitory in tests with alternating light levels. Judging from this one specimen, the arctic fox seems to be adapted for both bright and dim-light vision.

Coyotes (Canis latrans) in the wild are apparently mostly nocturnal but may be abroad at any time. Our juvenile animal was primarily diurnal on 24-hr cycles (Fig. 7-23, left). 4-hr cycles (with twilights) were quite revealing: the phasing within the cycles was determined primarily by absolute day and night light level, both very dim (Fig. 7-25, bottom right) and very bright (Fig. 7-25, bottom left) light being inhibitory. Alternating light-level tests also revealed inhibition in very bright and very dim light. Accordingly, all tests indicated that the vision of the juvenile coyote is best adapted for twilight activity and daytime activity in moderate light. If adult coyotes behave in the same way in laboratory tests, their mostly nocturnal activity may be an adaptation to minimize contacts with man.

Red wolves (Canis niger) and gray wolves (Canis lupus) are thought to have similar habits in the wild. The latter are primarily nocturnal in the summer but arrhythmic in the winter when prey are more scarce. The animals rest after feeding and appear sluggish after gorging on large kills. Our observations on the red wolf on 24-hr cycles were consistent with the field findings because they suggested good vision in both bright and dim light and an influence of feeding. Other tests were more discriminating; they suggested that our red wolf could see better in moderate daylight (0.9 ft-c) than in dim light (Fig. 7-26, left, second from bottom).

Long-tailed weasels (Mustela frenata) in the wild may be either primarily nocturnal or arrhythmic. On 24-hr cycles, one of our animals (#2) was arrhythmic (Fig. 7-24, upper right) while the other three ranged from 72 to 99% nocturnal. Very dim light and darkness were inhibitory. Accordingly, the visual system of the long tailed weasel appears to be adapted best for dim-light vision, suitable for daylight vision, and least well adapted for vision in very dim light. The activity type in the wild (the "ecological activity type") is probably determined primarily by predator pressure and prey availability, as modified after heavy meals.

Tayras (Tayra barbara) can be primarily diurnal or primarily nocturnal. Our specimens were primarily diurnal on 24-hr cycles, but they were not notably influenced by alternating light-level tests. Thus, though the vision of tayras appears to be best in daylight, it also appears to be good in dim light. The ecological activity type of these highly versatile animals may be determined chiefly by predator pressure-primarily diurnal where unmolested but primarily nocturnal where disturbed by man.

The grison (Galictis vitatus) is said to be chiefly diurnal, though one worker reported both day and night activity. Our animal was strongly diurnal and essentially uninfluenced by light-level changes and alternating twilights. These findings suggest very versatile vision that is best in daylight. Since grisons and tayras are tropical mustelids with many similarities, the same comments probably apply to the activity types of both.

Striped skunks (Mephitis mephitis) are primarily nocturnal, with occasional daytime activity. Our single specimen was primarily nocturnal on 24-hr cycles (Fig. 7-22, left), with 12-20% of activity occurring during the day. The other tests suggested good vision in both day and night light. Accordingly, comparison of laboratory and field findings suggests that the ecological activity type of the striped skunk is determined by factors other than adaptations of the visual system.

Comparisons
We can coordinate the above findings by dividing the animals into 4 groups. The first includes the adult ringtails, kinkajous, mongooses, adult gray foxes, kit foxes, the skunk and genets. Our knowledge of the phasing of these animals in the field is fairly good; all appear to be primarily or strictly diurnal or nocturnal. For all of these species our findings for 24-hr phasing are in agreement with field observations. Beyond this, our other tests showed that (1) some individuals of four of the species that are primarily or strictly nocturnal (or diurnal) in the field were not inhibited by bright light (or darkness); (2) gray foxes appear to have poor vision in dim light; and (3) although primarily nocturnal in the wild, the striped skunk appears to see well in both bright and dim light.

The second group includes the coatis, the grison, and the tayras, for which field results conflict. Our tests indicate that these species are adapted best for vision in daylight, but the coatis showed some nocturnal tendencies, and the grison and the tayras appear to have highly versatile vision. The ecological activity types of these species are probably determined mainly by proximity to man-primarily diurnal where unmolested but shifting toward nocturnality near human settlements.

The third group comprises the red fox, arctic fox, and long tailed weasel. As regards activity phasing, these species are very adaptable in the wild, with seasonal factors having primary influence on at least the first two. Our studies indicate that these animals are adapted best for dim-light vision, but that they also see well in daylight

Into the last group fall 4 of our 5 juvenile animals, namely, the two gray foxes, the coyote, and the red wolf. The findings for them may not be compared unqualifiedly with field results because of possible complicating maturational changes. These four juveniles showed arrhythmic tendencies. The coyote and red wolf appeared to be adapted for vision at light levels between 0.0001 and 13 ft-c. There is an indication that gray foxes, at least, become less arrhythmic as they mature.

Comparisons of the outdoor and indoor 24-hr phasing suggest that the artificial indoor light cycle with simulated twilights is a good substitute for the natural light regime. The average change in the activity phasing for the ringtails, kinkajous, genets, and mongooses after transfer indoors was only 0.5%. Excluding the juveniles, the figure was 2.3% for the gray foxes. For the red fox, it was 3.0%; for the arctic fox, 2.8%; for two kit foxes, 1.6%; and for the tayra, 2.3%. The individuals that showed large changes (9.24%) were either juvenile, arrhythmic, or belonged to species that appear to have highly versatile visual systems.

Influences of twilights on activity
The tendency of many animals to be active during dawn and dusk probably hinges upon these periods being prime times for hunting and food gathering. Twilights are often times of intermediate temperatures, and are the only periods when the activities of many animals overlap. A very influential factor for rodents and small carnivores is the fact that many insects are most active during twilights.

Twilights generally would be the best periods for small carnivores to hunt other small nocturnal animals-not only because the latter are intensely active at these times, but also because visibility would be better than at night, and the relatively dim light would provide partial protective cover for the small carnivores from larger predators (particularly the sharp sighted diurnal birds of prey). One also expects many animals to be active during twilights because of the advantages of utilizing all suitable available time. This would be true particularly of nocturnal animals, for atmospheric refraction shortens the night, and the shortest nights occur during the season when food is most abundant (and hoarding by rodents is at a peak).

Only eight animals showed no evidence of intensified activity during or proximal to twilights. The remaining 34 had marked to minor activity peaks, which accords with our hypothesis that high values of activity indices usually indicate conditions favorable for activity. For example, time active peaked for one kinkajou both in the hour after dusk indoors and in the hour after sunset outdoors; one genet had indoor dusk and post dusk (Fig. 7-24, bottom right) and outdoor post sunset peaks of indices. Time active peaked both before dawn indoors and before sunset outdoors for one kit fox, and speed peaked during and after both sunrise and dawn; speed and session lengths of the skunk peaked before dawn indoors and during and after sunrise outdoors (Fig. 7-22, left).

Difficulties getting results published
I had assumed that a pioneering paper of broad scope, novel approach, and unprecedented results would be very favorably received by reviewers and would receive ready publication. But I was overlooking two considerations. First, was there an appropriate journal in existence for results of this nature? Second, my first paper on my equipment ("Automatic Multi-Channel Sensing and Recording of Animal Behavior") was referred to as a "curious gadget" by a Science referee, and as a "gadget" by the Zoological Editor of Ecology, its eventual site of publication.

With such seeming disdain for the use of instrumented enclosures, even with small animals used in medical research, for whom the use of running wheels was common, an even more unfavorable reaction might be expected for enclosures for much larger, comparatively exotic animals, even including a coyote and wolf. At any rate, the paper was, at first, not "favorably received." As usual, though, reviewer comments enabled us to improve the manuscript. We first submitted to Ecology on June 13, 1973, for which James E. Heath was an editor at the time, and to whom the paper was referred for action. On Sept. 25, he informed me:

I regret that your manuscript, "influences of light on activity and phasing of carnivores" is not acceptable for publication in Ecology. My reviewers were quite critical of the length, degree of overlap of this paper with others, and of the appropriateness of the paper for Ecology. Both suggested that Animal Behavior is a more appropriate place. Both reviewers worked the paper over in some detail and I have included their comments for your use.

....After studying with you and working diligently at one time to learn your methods and approach, I find it doubly difficult to reject your manuscript. In any case, please accept my best wishes.

One reviewer began:

General - the paper is competently done and the rationale is explained well in the Introduction. However, as written, I do not think Ecology is the appropriate place for publication because the data presented are of interest only as a baseline which allows an ecologist to study those things which the authors specifically excluded, such as interaction with man and competing species, food supply, weather, etc. It is too long and appears to repeat a lot of the kinds of data being published elsewhere....

James had been a student some years before in one of my courses. Only in the last few months (2002) did I have another occasion to contact him in connection with a recent paper, "REM and NREM Sleep as Natural Accompaniments of the Evolution of Warm Bloodedness." James had been working for many years in the area of mammalian physiology, and was of great help.

At any rate, after appropriate revisions, on Nov. 14, 1973, we sent the same paper off to Oecologia, only to be informed on March 5, 1974, by Managing Editor Prof. Hermann Remmert, that:

....the Editors feel that this field has become so complicated that it is impossible to give a full picture from your data. Most animals differ n their phase angle to the light regime according to the season, to light intensity, and to endocrine factors. We think the restriction for at least two full years is needed when they shall be ok (see for instance the papers by Müller in Oikos).

Editor Remmert was referring to a 1969 article by Karl Müller on trout (Salmo trutta L.), which "was desynchronized in midsummer in Swedish Lapland and had a free running circadian periodicity. During this period it shifts phase from nocturnal to diurnal activity. In late summer it shifts back to nocturnal activity...." Remmert apparently was suggesting that our animals should be studied for about two years to obtain valid results. In any event we gave up on Oecologia and sent the revised manuscript to The American Naturalist on May 15, 1974. Eight days later, Editor R. R. Sokal replied as follows.

....I suspect that The American Naturalist is not a suitable vehicle for this particular paper....It seems to me that the paper is too strictly ecological or physiological for our pages and would be a much better contribution to a journal such as Ecology or Physiological Zoology. I also suspect that reviewers to whom I might send the paper would come up with similar recommendations, and you should then have lost several weeks before being able to resubmit the paper to another journal.

However, the subject matter of your paper is borderline as far as suitability for our journal is concerned and I am, therefore, leaving the decision on whether you wish to proceed with us or to withdraw the paper up to you. I would be very glad to send the manuscript out for review if you wish me to proceed. I look forward to hearing from you.

On June 3, 1974, we informed Editor Sokal that "there have been a number of papers published in The American Naturalist that were in much the same category as ours. Accordingly, we have decided to cling to the hope that our paper will be deemed to be suitable and to ask if you would be willing to proceed with it. On Oct. 28, 1974, Editor George C. Williams informed us that:

The reviews of your paper....have come in and are favorable [although Reviewer #2 felt it was "the wrong place" to publish it - JLK]. I am, therefore, accepting your paper for publication in The American Naturalist. I enclose comments of the two reviewers. Their criticism should be seriously considered in your final revision of the paper. A few excerpts from the reviews follow.

Reviewer #1: This is a significant piece of work, well conducted, and with important results. It has value to theoretical aspects of biology in allowing hypotheses to be drawn about the adaptedness of visual systems in various species, and I think it should be accepted by The American Naturalist.

Additional comments concerned cutting text by 25%, with less precision and detail given and less elaborate explanations and examples....too many illustrations....overwhelmed with material....reduce figure captions....weakness of field data on coyotes.

Reviewer #2: This report presents the results of comparative studies of the wheel-running activity of a broad spectrum of carnivores, with emphasis on the individual animal. As a study of one aspect of comparative behavioral physiology, the report has considerable merit, and I think most reasonable reviewers would grant that it should enter in some way into the published literature. The data themselves are often quite interesting, particularly in their attention to the individual animal; and clear differences between species are often evident, of a sort not necessarily anticipated.

Additional comments concerned uncertain ecological implications of wheel-running activity....a very big jump to extrapolate these results to any firm conclusions about field behavior....questions raised about implications of the results for the adaptedness of the visual system....but acceptable if taken with proper reservations....The American Naturalist simply seems to me to be the wrong place [to publish the paper].
On Nov. 27, 1974, we returned a revised manuscript, having given close attention to the reviewer comments and suggestions, with the text materially shortened, and one figure deleted. The paper was accepted by Editor Williams on Dec. 14.