Chapter 9

UCLA (1963-1995), Small Primates, Program Clocks, Compulsory Regimes, Light-Level Preferences, Miscellaneous Publications, Reprinting in Books, Reviews, Students

Overview
It was natural and of great interest, to extend our studies to mammals much more closely related to humans, namely, small primates. First studies in 1972 led to a very surprising and exciting finding, namely, that the small nocturnal primates running in wheels showed night-to-night or cycle-to-cycle pattern repetitions of a precision rivaling those of nocturnal WF mice.

As with nocturnal rodents and nocturnal carnivores, some of the primates: (1) were ceaselessly active throughout the night; (2) were directionally conservative, often locomoting in a single direction all night; (3) oriented relative to the position of the moon and twilight light sources; (4) sometimes repeated activity patterns from night-to-night; (5) locomoted faster during bright twilight phases than during dim ones; (6) displayed increased activity during dusk and early dawn and reduced activity during late dawn; and (7) emerged and retired in pace with seasonal progressions in sunset and sunrise.

I did not anticipate difficulty getting our exciting new indoor findings published. As usual, we first submitted to Science. To our surprise, Assistant Editor Ringle wrote in 1973, "I regret to say that we have decided not to publish it." It emerged that the main objection was from one referee whose objection revealed that he or she had not read the paper carefully: At any rate, rather than quibble with the editors of Science, where we published frequently, we decided to submit elsewhere. The paper, titled, Primate Locomotor Pattern Repetitions, Program locks, and Orientation to Light, appeared in Primates in 1974. Our outdoor results appeared in Science in 1976 under the title, "Activity of Nocturnal Primates: Influences of Twilight Zeitgebers and Weather."

Under natural conditions, activity rhythms usually become synchronized with (entrained to) the earth's rotational period as a result of responses to certain periodic environmental changes, or Zeitgebers, of which light level is often the most important. For many animals, the light-level Zeitgebers are believed to involve the twilight periods. Many animals customarily begin and/or cease activity during natural twilights, and artificial twilights also were found to influence the activity of numerous captive mammals.

We found that the time of activity onset of our small primates in outdoor enclosures usually fell in certain light-level ranges of dusk and kept pace with seasonal progressions of sunset time, suggesting a high degree of efficiency of entrainment of their clocks by light-level Zeitgebers.

To this time (1976) no comparative study of the light-level preferences of small nocturnal mammals had been published from my laboratory. This project was undertaken then and reported as the 3rd in the series, "Compulsory Regime and Control of Environment in Animal Behaviour" in Behaviour in 1976 under the title, "Light-Level Preferences of Small Nocturnal Mammals."

The most reliable behavioral guide to the overall adaptedness of the visual system probably is an animal's ambient light-level preferences during activity. In this study we used two approaches to pinpoint such preferences. In the compulsory or imposed method, we altered the ambient light level stepwise through an appropriate range during activity periods. In the volitional method, the animals, themselves, altered the levels in 10 steps (darkness to 20 ft-c =.200 lux) by pressing levers. In both approaches we determined the influences of different light levels on activity in exercise wheels.

During activity, most individuals were highly selective for light level. Since the preferences generally correlated well with habits and habitat preferences in the wild, volitional control of light probably gives a reliable indication of overall state of adaptedness of the visual system of small nocturnal mammals. Thus, such tests could serve as independent guides for interpreting retinal histology.

The above study using adults of 9 species of small nocturnal mammals revealed preferences for darkness or dim light. These generally were species specific and correlated with habits and habitat preferences in the wild. In contrast, most small diurnal rodents preferred bright light. Accordingly, the results of such tests also probably give a reliable indication of the overall state of adaptation of the visual system of small diurnal mammals.

In another paper, "Light-Level Preferences of Cactus Mice," Peromyscus eremicus," for all 9 mice, the time spent running in the wheel had marked, minor, incipient or presumptive peaks at level 5 (0.0014 lux) or level 6 (0.0025lux). These peaks probably reveal the optimal light level for the animals' vision. But the major peak in the active time of most individuals was in darkness (or extremely dim light). This difference from the habits of other small nocturnal mammals could be accounted for by cactus mice ecology.

Articles on my animal behavior studies in newspapers, and mention on radio and TV, were too numerous, and are of too little note, to warrant recording here. I did contribute a few popular articles on animal behavior. The first was in 1970, the lead article in Zoonooz, a monthly publication of the San Diego Zoological Gardens. A second article in 1975 was introduced by Clyde A. Hill, Curator of Mammals, characterizing my findings as "a significant breakthrough in zoo exhibit technology that occurs about once in every decade."

Next came the lead article and cover illustration (a mouse running with a clock and pursued by a wolf) in New Scientist in 1976. There followed another article in 1977 in which I  describe a slow loris that on one day altered the light level 3,674 times, a record.

Laudatory references to my animal behavior work in books and articles appeared in 1965 by W. H. Thorpe, the renowned British ethologist in his chapter in Ideas in Modern Biology, by J. A. Moore; in 1968 in L. B. Slobodkin's review of my chapter in Systems Analysis in Ecology in Science; in the K. E. Weick 1999 review in Science of my chapter in Naturalistic Viewpoints in Psychological Research;in 1970 in Robert Ardrey's book, The Social Contract, referring to my Behavior of Captive White-Footed Mice paper in Science;and in 1971 in the Charles L. Kutscher volume, Readings in Comparative Studies in Animal Behavior, in which my paper, "Behavior of Captive White-Footed Mice," in Science was reprinted and discussed by Kutscher.

My additional publications in animal behavior, book chapters, etc., included: in 1966, Chapter 5, "Automatic Monitoring of the Activities of Small Mammals," in Systems Analysis in Ecology; in 1969, a chapter, "Behavior of Captive White-Footed Mice," in Naturalistic Viewpoints in Psychological Research, Edited by E. P. Williams and H. L. Raush; in 1970, a chapter, "Behavior: Confinement, Adaptation, and Compulsory Regimes," in The Science of Psychology: Critical Reflections, Edited by D. P. Schultz; in 1971, a chapter, "Behavior of Captive White-Footed Mice;" in Readings in Comparative Studies in Animal Behavior by C. L. Kutscher; and in 1979, a chapter, "Life in the Twilight Zone," in Science Year, The World Book Science Annual.

Also listed are the titles of my reviews of 11 books on water and biological membranes, and the names of my 15 students who earned Ph.D. degrees.

What had began about 20 years earlier as a simple question of how much sleep a healthy deer mouse requires led my students and me to branch out down many unexpected, exciting paths. Studying a variety of aspects of behavior and learning on the way, we soon found our attention focused almost exclusively on the roles light plays in the lives of animals. Several years of intensive laboratory studies of these roles inevitably raised questions that could only be answered by field studies. In turn, these studies compelled us to branch out along other unforeseen paths.

Teaching

My teaching aims and practices, and interactions with students are discussed in detail. Unfortunately almost all student comments on my teaching were lost accidentally on my office relocation after retirement from teaching in 1990. However, sufficient comments were retained, mostly accidentally, and received on subsequent encounters, to be representative.

Pet Peeves

I include a few words on my pet peeves. One of these concerns word usage that is utterly illogical, yet is employed regularly 99.99%  of the time. It is so thoroughly ingrained that the fact of its being illogical will likely carry no weight. Another peeve, thoroughly ingrained in all weather forecasters and very many scientists, concerns their belief that the words hot and high, cold and low, warming and increasing and cooling and decreasing become synonyms when used with the word, "temperatures." Obviously something as awry with their thinking.
End Overview

Primate Locomotion Pattern Repetitions, Program Clocks, and Orientation to Light

It was natural and, of course, of great interest, to extend our studies to mammals much more closely related to humans, namely, small primates. I had previously studied one diurnal monkey, a male pig-tail macaque (Macaca nemestrina), but not in great detail. The present studies were undertaken with my doctoral student Charles Peters in 1972. Charles was an anthropology major, but became so much interested in animal behavior, after taking my courses in Behavioral Research Problems, that he requested to do his thesis jointly with Prof. R. Edgerton and me on small primate behavior, using the techniques of my laboratory.

Our plan was to carry out both outdoor studies on the roof of the Life Sciences Building and indoor studies, as already described for WF mice and carnivores. Our studies led to an early very surprising and exciting finding, namely, the small nocturnal primates running in wheels showed night-to-night pattern repetitions of a precision rivaling those of nocturnal WF mice.

Our experimental animals included 1 male owl monkey (Aotus trivirgatus), 2 male and 1 female slow lorises (Nycticebus coucang), and 2 male and 1 female bush babies (Galago senegalensis), all mature and wild caught. They were fed mealworms and a varied assortment of fruits, nuts, and pet chows, daily, without disturbance. As in virtually all studies, water was available ad libitum. The 122-cm diameter activity wheel, enclosure environments (natural weather outdoors, 19-23°C and 40-60% relative humidity indoors), and light sources have already been described.

Two indoor light cycles with artificial twilights (lasting 54.5 min) were employed, one of length 24 hr and one of length 4 hr. The artificial twilights roughly duplicated the relative light-level changes occurring locally during the beginning of dawn and end of dusk. The rationale for using 4-hr cycles is: (1) such cycles determine whether the responses to simulated twilights will occur at any time during the 'day,' or whether they occur only if the light changes take place at 24-hr intervals; and (2) the quantitative responses to untimely dawns and dusks help to confirm the type of phasing for which the visual system is adapted best.

As with nocturnal rodents and nocturnal carnivores, some of the primates: (1) were ceaselessly active throughout the night; (2) were directionally conservative, often locomoting in a single direction all night; (3) oriented relative to the position of the moon and artificial twilight light sources, sometimes so markedly that one could program running direction almost at will; (4) exhibited individually characteristic activity patterns; (5) sometimes repeated activity patterns from night-to-night; (6) locomoted faster during bright twilight phases than during dim ones; (7) displayed increased activity during dusk and early dawn and reduced activity during late dawn; and (8) emerged and retired in pace with seasonal progressions in sunset and sunrise.

Several remarkable activity pattern repetitions were observed in the course of this study, of which I give illustrations for a female slow loris on Sept. 7 and 8 (together with a detailed description), a male bush baby on Aug. 17 and 18, a female bush baby on July 30 and 31, and another male bush baby on June 28 and 29, all in 1973, during 3 consecutive indoor 4-hr cycles (Figs. 9-1 & 9-2).

The different characteristics and directional properties seen in slow loris patterns (Fig. 9-1, upper) represent primarily gaits of different rhythm and speed. The first sign of activity on both Sept. 7 and 8 was low amplitude rocking of the wheel during mid (barely perceptible at a1) 'first' dusk, as the animal climbed into the adjoining nest cage from its customary sleeping site at the bottom of the wheel. After feeding for about 20 min it re-entered the wheel and engaged in extensive bouts of essentially unidirectional 'high-speed' activity (b1). Minor very-low-speed activity that resulted in rocking (d1) occurred during both mid-to-late first dawns. Similar low speed bouts began at the end of both first dawns and continued into the first bright-light periods (e1), after which the animal retired.

It climbed out of the wheel again to feed about 20 min into both second dusks (a2), at the same relative time (within seconds) as during the first dusks. After feeding, it re-entered the wheel and engaged in extensive bouts of essentially unidirectional locomotion (b2) similar to the first bouts but slower. Intermediate-speed, essentially unidirectional bouts began at the beginning of both second dawns (c2). Low-speed bouts occurred during the last half of both second dawns (d2). Partially bidirectional, moderate to high-speed spurts commenced at the beginning of both second bright-light periods (e2). These transformed partly (Sept. 8) or completely (Sept. 7) to low-speed activity before terminating during the bright-light periods, when the animal again ceased activity.

It became active again during both third dusks (a3) at the same relative times. It did not feed a third time, though, but launched directly into moderate-speed bouts that gave way to sustained unidirectional low-speed bouts (b3) that lasted 2 h, terminating during mid third 'dawn.'. It remained on a 24-hr rhythm; sleeping and resting in the wheel for the 14 h between the 2 records, even though the 4-hr cycles continued throughout this period.

Another remarkable pattern repeat is that of the male bush baby on Aug. 17 and 18 (Fig. 9-1, lower), including spikes (f) of high-speed locomotion only about 3 min out of phase with each other. The chief difference between the patterns was the occurrence of an activity bout (h3) during the third dim light phase on Aug. 18. This animal often locomoted non-stop in a single gait or routine for several hours.

The pattern repeats by the female bush baby (Fig. 9-2, upper) illustrate the scalloped appearance of twilight running records of several primates and numerous other mammals we studied. The scalloping depends primarily on the tendency of locomotor speed to be proportional to the light level in the range of twilights. The other male bush baby was much less active but it also repeated patterns (Fig. 9-2, lower).

Differences in speed and degree to which activity was sustained by the bush babies reflect qualitatively and quantitatively different locomotor routines. These included such acts as scurrying on all fours, "riding" the rotating wheel, jumping on, off, and over the axle, and jumping to the bottom from the receding face, and then from the bottom to the approaching face.

Among the three species, locomotor orientation of the slow lorises and owl monkey was influenced strongly by the position of light sources. The slow lorises responded both to the position of the moon and the simulated twilight sun. The influence of the former was confirmed by alternation tests in which it appeared first to the east and then to the west in successive 4-hr cycles, whereas the influence of the simulated twilight sun was confirmed by changes in running direction during, or at the beginning or end of, twilights (records not included).

The impressive pattern repetitions described in 1968 for nocturnal old field mice occurred during 24-hr cycles in the unchanging dim light of the night period. Since the only time cues were the light changes of dusk and dawn, the pattern repetitions had to depend primarily on a close synchrony (to fractions of a percent of the same time after initiating activity) of internal mechanisms that determined the beginning and ending of activity during the course of the night. In other words, physiological timing mechanisms must have provided the reference points for beginning and ending of similar activities at the same times during successive nights.

For our primates, though, light source and light-level changes repeated every 4 h. Accordingly, if the locomotor patterns depended entirely on responses to the cyclic light changes, one would expect to find the same pattern repeated every cycle. The degree to which the patterns changed from cycle to cycle is primarily a measure of contributions of internal time programming factors (the 'program clock') to the form of the pattern, while the degree to which the patterns were the same on both 'nights' is a measure of the degree to which the internal program remained unchanged.

Internal time programming must have played a major role in the generation of the pattern repetitions of the female slow loris (Fig. 9-1, upper) because its pattern differed markedly from one cycle to the next. In part, the changes reflected persistence of the animal's habit (on 24-hr cycles) of locomoting progressively more slowly from dusk to dawn. While this habit could account for the decrease in speed from dim light periods b1 to b2 to b3, it could not account for the other pattern changes. These other changes could depend partly on differences in responses to identical light stimuli presented at different times during the 'night' period of the animal's internal clock. Other internal factors that can differ from 'night' to 'night' must have been involved, though, because the patterns on other nights (not shown) were not identical to the one repeated on Sept. 8.

The tendency of our nocturnal primates to orient relative to the positions of light sources and the enclosure environment suggests a potential for using celestial light sources and prominent topographical features as navigational reference points in the wild. Together with the conservatism of movement patterns suggested both by periods of sustained unidirectional running and repeats of activity patterns these findings support conclusions for our nocturnal primates similar to those drawn for nocturnal rodents and carnivores, namely, that the primates probably maintained a continual 'awareness' of their immediate surroundings and directions of movements in the laboratory, and that in the wild they may use both distant and near reference points as aids in 'keeping close track' of absolute position and displacement from the nesting area.

The pattern changes that occur from one 4-hr cycle to the next apparently reflect changes in physiological factors (in addition to degrees of satiation of hunger and thirst) over the course of subjective activity periods. When the light level is constant for long periods, as during the day or night periods of 24-hr cycles, these changes may be hidden or expressed only in relatively unobtrusive ways. But when light conditions change cyclically over the course of the subjective activity period, the changes may receive magnified expression, in the form of complex modifications of the locomotor performance.

As  often in the past, I did not anticipate that we would have any difficulty getting these exciting findings published. In my letter of submittal I wrote, "[w]e are very enthusiastic about this paper, which should be of the most widespread interest of any to come from my laboratory. It reports the finding in primates of many of the remarkable locomotor responses to light, and other facets of locomotor behavior that have been detected by us in numerous other mammals. This suggests deep rooted neurobehavioral similarities between widely different groups of mammals insofar as responses to ambient light are concerned. Its widest appeal will hinge on the fact that owl monkeys, bush babies, and slow lorises are much more closely related to man than the animals of earlier studies.

As usual, we first submitted the paper to Science. To our surprise, Assistant Editor J. E. Ringle wrote, on June6, 1973, "[I] regret to say that we have decided not to publish it. By way of explaining our decision, I am enclosing the referees' comments. Excerpts from these follow.

Referee 1: I feel that this is quite an interesting paper, especially the findings of directionality of the nocturnal activities with respect to twilight, dawn, and the "moon."

There are two minor points that I feel the authors should change......

Referee 2: As exciting as the research reported in this paper is, it appears to represent a pilot investigation rather than a systematic piece of research of the type usually reported in Science. Because of this, I do not recommend it for publication.

The primary shortcoming of the study is that it reports the behavior of the animals for only a short period of time. We see gross motor activity for four different animals with the longest period of observation being four days. Most studies of this type will examine the activity of the subjects for at least seven days, and preferably for periods up to thirty days....

The recommendations of Referee 1 could have been taken into account easily, and would have been no cause for rejection. The comments of Referee 2, more than anything, show that he did not read the paper carefully, perhaps becoming careless in his apparent efforts to find fault. If there is anything our laboratory cannot be accused of, it is that we do not study our animals long enough. One of our principal findings was that captive animals may take many days, even weeks, to adapt to the experimental situation.

It is stated in the Results section that "Animals were studied first outdoors and then indoors on 24-hr light cycles for a period of from 4 to 10 weeks each. Under these conditions they were strictly nocturnal (reference to our 1976 Science paper, in preparation at that time; see below)." The shorter periods referred to by Referee 2 were those remarkable instances in which pattern repeats occurred, for some of which Figures were included. At any rate, rather than quibble with the editors of Science, since we published there frequently, we decided to submit elsewhere. The paper, titled "Primate Locomotion Pattern Repetitions, Program Clocks, and Orientation to Light," was submitted to Primates and appeared in the following year (1974;15:209-217).

Activity of Nocturnal Primates: Influences of Twilight Zeitgebers and Weather

Other outdoor results of the foregoing study appeared in Science (1976;191:83-86) titled as above. We dealt with Assistant Editor Ringle again with this paper. The reviewer comments can be summed up by the following two quotes:

An interesting paper that points the way to some new areas for investigation,....In general these conclusions seem justified, and this is a useful contribution to our knowledge of primate activity cycles.

Under natural conditions, activity rhythms usually become synchronized with (entrained to) the earth's rotational period as a result of responses to certain periodic environmental changes, or Zeitgebers, of which light level is often the most important. For many animals, the light-level Zeitgebers are believed to involve the twilight periods. Many animals customarily begin and/or cease activity during natural twilights, and artificial twilights also influence the activity of numerous captive mammals.

It is virtually impossible to determine the isolated influences of natural twilights through field studies because of the confounding influences of other environmental variables, such as cloud cover, temperature, and food availability. These complications may obscure functional relationships that only can be observed when the naturalist's observations are complemented with the results of controlled studies, such as those described here.

We found that the time of onset of activities of bush babies (Galago senegalensis), slow lorises, (Nycticebus coucang), and an owl monkey (Aotus trivirgatus) living in outdoor enclosures usually fell in certain light-level ranges of dusk and kept pace with seasonal progressions of sunset time. Apparently their internal clock usually aroused our animals at about the time of sunset but well before the Zeitgeber. If light conditions were favorable, the evening's activity commenced. If the light was too bright, only a brief emergence was recorded; the animal rested, entered or left the wheel, groomed, or ate before eventually commencing sustained locomotion.

The dawn Zeitgeber may have been without effect when animals retired very early, whereas when activity continued through dawn it doubtless was registered. But it was not unusual for an animal to continue activity after sunrise in overcast weather. Excessive heat and cold were inhibitory. Occasional brief dawn re-emergence, after ceasing activity early, suggest that retired animals continued, for a time, to maintain awareness of the outside light level.

Highly consistent emergence and cessation times during some periods of markedly variable day to day cloud cover support the suggestion that specific stable post sunset and pre sunrise twilight segments are the light-level Zeitgebers for these primates (Fig. 9-3). This evidence was most convincing for cases of rapid day to day progression of sunset and sunrise times. In this connection, the seasonal changes in sunset and sunrise times in Los Angeles occur 2 to 3 times faster than in the subtropics and tropics, while the corresponding changes in day length are greater and the twilights last longer.

Accordingly, the animals had to make much greater seasonal adjustments using twilight cues that were more gradual and difficult to detect ("the twilights last longer"). In view of the fact that the ancestors of these primates were not exposed to temperate latitude conditions since at least the Miocene, our findings suggest a high degree of efficiency of entrainment of biological clocks by light-level Zeitgebers.

Light-Level Preferences of Small Nocturnal Mammals

To this point (1976) no comparative study of the light-level preferences of small nocturnal mammals had been published from my laboratory. This was the project undertaken with my doctoral student Roy Havenhill, reported as the 3rd in the series , "Compulsory Regime and Control of Environment in Animal Behaviour" in Behaviour (1976;59:203-225) under the above heading.

The most reliable behavioral guide to the overall adaptedness of the visual system probably is an animal's ambient light-level preferences during activity. In this study we used two approaches to pinpoint such preferences for a wide variety of captive small nocturnal mammals. In the compulsory or imposed method, we altered the ambient light level stepwise through an appropriate range of levels during activity periods. In the volitional method, the animals, themselves, altered the levels in 10 steps (darkness to 20 ft c = 200 lux) by pressing levers. In both approaches we determined the influences of different light levels on activity in exercise wheels, chiefly on the amount of time active and locomotor speed.

Of the two methods, the volitional one has the important advantage that the animals can control the amount of activity at each light level without restriction. With the imposed method, the level exposures are compulsory; the animals are restricted to expressing preferences primarily by being active or inactive. Accordingly, the volitional method has much greater resolving power.

The experimental animals were adults of 9 species in the families Cricetidae (the mice) Didelphidae (the mouse opposums), Sciuridae (flying squirrels), and Geomyidae (the gopher). We used 3 flying squirrels (Glaucomys volans), 4 meadow voles, 2 each of Microtus californicus and Microtus pennsylvanicus, 3 wood rats (Neotoma lepida), 2 Florida mice (Peromyscus floridanus), 2 California mice (Peromyscus californicus), a pocket gopher (Thomomys bottae), 3 canyon mice (Peromyscus crinitus), and 2 mouse opossums (Marmosa mitis). Experimental enclosures and conditions already have been described.

During activity, most individuals were highly selective for light level. Behavior not only was species specific, but members of the same species often gave identical results (Fig. 9-4). Since the light-level preferences generally correlated well with habits and habitat preferences in the wild, volitional control of light level probably gives a reliable indication of the overall state of adaptedness of the visual system of small nocturnal mammals; such tests could serve as independent guides for interpreting retinal histology.

Both the mouse opossums and gopher spent most of their active time in total darkness and much of the remaining time at level 2 (0.7% of starlight). For the flying squirrels, active time generally peaked at level 2 or 3 (2.1 or 7.5 x 10^-5 lux), for the Florida mice it peaked at level 5 (0.0045 lux = 50% of light on clear moonless night), and for the California mice at level 7 (0.06 lux = about 3 x full moon). Individual woodrats and canyon mice had the most spread between the positions of their peaks for active time and visits at each light level - levels 5 to 7 for the former and 5 to 8 for the latter (Fig. 9-4).

Meadow voles were the only animals to have dual light-level preferences (darkness and level 4, at 4.5 x 10^-4 lux). These dual preferences may be related to the fact that meadow voles need to feed at regular intervals and are active around the clock in the wild. Components of persisting physiological cycles, particularly digestion, may have influences the degree to which visual and non visual factors determined the voles' light-level preferences; thus, non visual factors may have predominated primarily during digestive phases, and visual factors during primarily non digestive ones (Fig. 9-4).

Eight of the animals showed preferences for dimmer levels during inactivity; 3 of these 8 showed marked shifts to darkness. For 13 of the 20 animals, running was fastest at the light levels preferred for activity. The results for the gopher and flying squirrels accord with our hypothesis that the proportionality of the running speed of certain rodents to light level is the result of selection for individuals that run as fast as navigational safety permits during twilights. Thus, factors that lead to such selection would not be expected to play a significant role for gophers (travel mostly under ground) and flying squirrels (travel mostly by gliding), and these 2 species did not exhibit the speed light level dependence.

Light-Level Preferences of Cactus Mice

The above study and others of light level selection during activity of adults of 9 species of largely or strictly nocturnal rodents and a didelphid revealed preferences for darkness or dim light (Fig. 9-4). These generally were species specific and correlated with habits and habitat preferences in the wild. In contrast, most small diurnal rodents preferred bright light. Accordingly, the results of such tests probably give a reliable indication of the overall state of adaptation of the visual system of small mammals that have essential simplex vision (almost exclusively either rod or cone cells) and, thus, could serve as independent guides for interpreting retinal histology.

In these exploratory studies different light levels were achieved by methods in which color temperature changes occurred. In other words, as the light level was dimmed the light became more red. Accordingly, to perfect the technique as a procedure for assessing the overall state of adaptation of the visual system of small mammals, a new method has been developed to achieve light-level changes at constant color temperature.

This paper, "Light-Level Preferences of Cactus Mice, Peromyscus eremicus," was the fourth in the series, "Compulsory Regime and Control of Environment in Animal Behaviour" (Behaviour 1978;65:161-181). The volitional light-level preferences at constant color temperature (2390°K, similar to white light from a flashlight) of 9 closely related, captive born cactus mice were determined by allowing them a choice between light levels ranging from darkness to 1.1 lux (0.11 ft c). The levels could be altered bidirectionally to brighter or dimmer values, one step at a time, in sequence, by pressing levers. The mice were confined in exercise wheel enclosures (Figs. 2-11  2-12) and tested and retested at ages of 4 to 35 months.

For all 9 animals, the time spent running in the wheel had marked, minor, incipient or presumptive peaks at level 5 (0.0014 lux) or level 6 (0.0025lux) (Fig. 9-5). These peaks probably reveal the optimal light level for the animals' vision. But the major peak in the activity of most individuals was in darkness (or extremely dim light). There also was generally a marked tendency for the animals to spend a greater percentage of inactive time than active time in darkness.

Five animals retested after a period of at least 5 months showed changes in preference, there being a tendency for the minor preference for dim light either to increase with age or to appear first long after maturity (Fig. 9-5; compare 2 plots at right with those at left)..

The light level regimes to which small nocturnal animals are exposed are analyzed in terms of a scheme involving two sets of factors-light-level preferences and factors unrelated to these preferences (weather, predator and prey habits, heavy phases of digestion, etc.). Although both sets of factors determine light-level preferences in the wild, only the light-level preferences appear to be operative in captivity.

Cactus mice differ from most other species of small nocturnal mammals we have studied in an important regard; as with canyon mice and desert woodrats, they occupy highly exposed habitats, specifically rocky outcrops and low hot deserts with sandy soil, often in stands of cactus. Accordingly, although the habitats of most of the other species studied probably provide numerous sites where the animals can take cover in the course of surface activity, the burrows themselves may be the chief sources of cover for cactus mice.

For that reason, cactus mice in the wild may visit their burrows much more frequently than do individuals of other species. But a greater tendency of the cactus mouse to visit the burrow probably is equivalent to a greater tendency to seek darkness at times when vision is unnecessary. This difference in habitat and possible differences in habits of the cactus mouse may be the bases for their great preference for darkness or extremely dim light in captivity.

In this connection, although studied only as adults, 2 of the 3 desert woodrats did have minor peaks in darkness, while one of the 3 canyon mice had a slight peak there (Fig. 9-4). In the case of the gopher, which is superbly adapted for life in tunnels and burrows (and, hence, for activity in the dark), the finding that the captive animal strongly prefers darkness at all times requires no reconciliation.

On the other hand, the preference of the mouse opossums for darkness during activity (Fig. 9-4) remains paradoxical, for the active mouse opossum in the wild relies heavily on vision (even though it usually confines itself to dim light areas). As with the gopher, more extensive studies may reveal a dim-light range in which mouse opossums see best.

 'Popular' articles on animal behavior in magazines

Articles on my animal behavior studies in newspapers, and mention on radio and TV, were too numerous, and are of too little note, to warrant recording here. I did, however, contribute a few 'popular' articles on animal behavior in two magazines, which are mentioned here in chronological order.

The first was in 1970, the lead article in Zoonooz (42:4-7) titled "Mammalian Activity." This was a general article on the techniques used in my laboratory to study captive mammals of all kinds, which contained the illustration of a fossa (Fig. 7-12, lower) treading in a large open faced exercise wheel.

Next came "The Race Through Twilights" in 1975, also in Zoonooz (48:13-16), in which I described the marked influences of artificial twilights on the activity of nocturnal mammals in the laboratory. This article was introduced by Clyde A. Hill, Curator of Mammals, as follows.

About once in every decade a significant breakthrough in zoo exhibit technology is made. The Race Through Twilights describes the underlying principle which has enabled us to propose a new method of displaying many kinds of animals. Most small mammal houses have two things in common, their displays resemble those of aquariums and most of the animals are inactive much of the time. By creating and prolonging an artificial twilight, these dormant exhibits will become alive with activity and each animal's waking behavior can be observed by the zoo visitor. Dr. Kavanau uses an exercise wheel to gather data. Such devices probably will have limited use in the small mammal house of the future because each exhibit will be carefully designed to provide naturalistic activity areas." In other words, sequential artificial twilights could be provided for small mammals during zoo visiting hours, which would tend to keep the animals active at those times, rather than only at night, as usually is the circumstance.

Next came, "Animals in a Twilight World" in 1976, the lead article and cover illustration in New Scientist (71:574-576). Introduced by the editors on the Contents page as follows.

As twilight descends on the animal world, many small creatures shift into a new gear of activity; they are anxious to maximize their chances of collecting food while trying to avoid becoming the supper of ever present carnivores. Using artificial days and nights, California scientists have shown how the animals' lifestyles help to balance opportunities and hazards in the environment.

This article included running records of a canyon mouse and an eastern chipmunk during sequential simulated dawns and dusks, with the typical scalloped patterns caused by running fastest in the brightest light, as well as an outdoor record for an eastern chipmunk, showing a marked high speed peak during a natural dawn.

There followed another article headed by a photograph of two slow lorises in New Scientist in 1977 (74:530-532), titled, "How Much Light Do Animals Like? The Editors subtitled this article, "Allowing animals to alter light levels at will reveals that they have sharp preferences that are admirably suited to their way of life." One slow loris of this study was so taken with altering the lights that it did little else. It holds the record of 3,674 alterations per day.

References to my work on animal behavior in books and articles

1965. In his chapter in Ideas in Modern Biology, by J. A. Moore, Natural History Press, Garden City, NY, W. H. Thorpe, the renowned British ethologist, referring to my 1963 Wheel-running paper in Behaviour, wrote as follows.

To conclude this section I would like to refer to the remarkable studies of Kavanau who showed that if the deer mouse (Peromyscus crinitus) is confined in a wheel running device, so arranged that arbitrary regimes of wheel running can be programmed for it, and the mouse given power to change these by pressing a lever, the mouse tends to react to the arbitrary imposition of the regime by opposition to it.

Thus if animals have the power to counteract the effects of initiation or cessation of environmental modifications, they may promptly do so. Confined animals in this situation repeatedly exercise this control. They find it rewarding to obtain and exercise a degree of control over the environment perhaps in partial substitution for the control exerted in the wild (but withdrawn by confinement), perhaps in any circumstances.

Taken alone, the nature of the specific stimulus or activity is an unreliable guide for interpreting the behavior of small mammals upon whom it is forced or to whom it is presented unexpectedly. Stimuli that are rewarding (or punishing) in certain circumstance can become punishing (or rewarding) in other circumstances.

1968. In the L. B. Slobodkin review in Science (159:416-417); of my chapter in Systems Analysis in Ecology, Slobodkin writes:

Kavanau has placed mice in what is essentially a computer environment control system in which the computer is informed of the behavior of the mice and the mice can, in turn, control the computer so as to modify their own environment in a variety of ways. The behavior revealed by this arrangement makes the mice seem much more exciting than any animals that ever occupied a Skinner box or desperately leaped from an electrified platform.

I am fascinated and delighted by any study which can unequivocally conclude that, "mice of the genus Peromyscus tend to react to the arbitrary imposition of a regime by opposition to it...." Not only is this a promising foretaste of new problems that will be approachable only through highly automated data processing, but somehow it lends hope to the world.

1969. In the K. E. Weick review in Science (166:866-868) of my chapter in Naturalistic Viewpoints in Psychological Research, Weick writes:

The papers show what naturalistic methods can accomplish when competently used (papers Menzel, Kelley, Kavanau)....The two most persuasive papers involve infrahuman research: [a review of Menzel paper with primates followed. JLK] ....The same emphasis of the shifting definition of objects as a function of context pervades Kavanau's chapter about captive white-footed mice. Although Kavanau stays in the laboratory, he works on a question that is relevant for naturalistic inquiry: if I bring wild caught mice and their undomesticated repertoires into an artificial environment, of what are they capable, in what ways will they try to modify imposed regimes, and what can I infer from this about their adaptations to natural conditions?

A glimpse of what he has learned about their capability can be had from a description of the vertical maze system in which he placed some animals. The system is '96 meters long, has 1,205 90° turns, 48 meters of vertical passageways, and open into 445 blind alleys, the latter occupying 63% of the total space. Mice learned to traverse the system in as few as two days, a performance that is even more surprising given that there was no extrinsic reward and no prior deprivation, and that the maze had to be learned both forward and backward because there was only one point of entry and exit.

On the question of how captive mice modified imposed regimes, the most striking finding is that mice avoid activities not initiated by themselves, even activities that they engage in repeatedly when they can do so of their own volition, and they similarly resist being forced to stop an activity. Part of the fascination with this phenomenon is that it is virtually identical to one uncovered in human actions by Brehm (A Theory of Psychological Reactance, 1966) which he labels "psychological reactance." As a clue to what Kavanau finds regarding how mice function in their natural habitats, it is sufficient to mention the lengthy program of illuminance experiments which support the idea that mice use the twilight sun and moon as "navigational" references when they are active at night.

Although I have paid more attention to findings in these two papers than to the insightful methodological points raised by their authors, this is simply because the findings are a more eloquent testimonial to the value of this method than is argumentation. Unfortunately, this eloquence is less apparent in the "human" papers....However, the days of such impediments may be numbered if researchers follow Kavanau's example of using the laboratory as a field situation, and Kelley and Menzel's of using the field as a laboratory situation....

1970. In Robert Ardrey's book, The Social Contract, referring to my Behavior of Captive White-Footed Mice paper in Science, he wrote (pp. 98-99):

So blocked have we been by the tyranny of reinforcement theory with its rewards and punishments that today we are only beginning to learn about learning. In a crashing experiment at the University of California, Los Angeles, the iconoclastic zoologist J. Lee Kavanau built a maze with 427 meters of linear runways, 1,205 ninety degree turns, and openings into 445 blind alleys occupying over 50 percent of the space. Into the maze he turned not the domesticated, highly inbred animals that have furnished us with the supposed proof of reinforcement theory, but wild caught white-footed mice. Without pressure of deprivation, without threat of punishment or lure of reward, they learned to run the entire maze not only forward but backward in two to three days. "These activities appear to be the expression of inherited tendencies to explore and develop wide ranging motor activities," wrote Kavanau. "It is unlikely that these remarkable learning performances even begin to approach the capacities of the animals."

1970. In his book, Culture and Biological Man, referring to my 1963 Wheel running paper in Behaviour, E. D. Chapple wrote (p. 131):

Kavanau found with deer mice (Peromyscus) that, on a motor wheel on which they could run more freely than one on which they did all the work, once they learned to turn the motor off and on, they would rune only when they turned on the motor. If the experimenter did so they, would refuse to run. Such recalcitrance in taking the initiative clearly helps to confuse the issue as to what is actually going on.

1971. In the Charles L. Kutscher volume, Readings in Comparative Studies in Animal Behavior, in which my 1967 Science paper, "Behavior of Captive White-Footed Mice" was reprinted, Kutscher discussed it as follows.

Kavanau's paper raises the problem of the rational for the laboratory study of animal behavior and the best means of doing this. He reasons that bringing a highly inbred strain into the laboratory and subjecting it to a sterile environment rigidly controlled by the experimenter may tell us very little about the behavior of wild and relatively unconfined animals. This sounds like the old Psychologist ethologist controversy again, but Kavanau adds a considerable amount of data from his study of the white-footed mouse.

He shows that these mice will seize upon every opportunity to manipulate the environment, from chewing cardboard cartons to shreds to choosing to run a square activity wheels instead of round ones, to learning to  traverse a complex maze rapidly with 445 blind alleys although no intrinsic reward was given and the animals were not deprived.

These animals learned complex sequences of lever pressing and shutter pushing in order to get food or water or to leave the nest. Almost complete records of the animals' activity indicated when they ate, drank, slept, exercised, and eliminated, permitting correlations of the occurrences of these activities and determination of the mean times between the occurrences. Animals were allowed to set the illumination level by manipulation of appropriate controls.

In nature, of course, the mice do not control illumination by pushing buttons, but they do move into their burrows during daylight and emerge during periods of reduced illumination. In short, Kavanau's elaborately constructed apparatus enables one to record an immense amount of information about the daily response patterns of his animals and it enables his animals to manipulate the environment to a larger degree than in most psychological experiments.

Which approach is the best one? Again we have to consider the approach of the scientist who wants to know whether a particular variable (for example, food deprivation) has an effect on behavior (for example, wheel running). He keeps all other variables constant and regulates degree of food deprivation and allows the animal the opportunity to run the wheel, but little else.

Kavanau's approach and that of many ethologists and ecologists, seems to be that of getting as complete a picture of the animal's behavior as we can by allowing the animal a wide variety of response opportunities. Kavanau appears to be testing no particular theory or working on no specific narrowly defined problem as do most psychologists. It is the view of the writer and others (for example, Hinde) that both approaches need to be exploited and an attempt made at synthesis of the data from both approaches.

Kavanau's data raise some interesting problems which may not be answered for some time. For example, is the white-footed mouse superior to the laboratory rat since this mouse can learn a very complex maze in a few days and rats sometimes take a large number of trials to master a T maze with one blind alley? There is little evidence of maze learning in animals other than the inbred laboratory strains. Perhaps Kavanau's work will stimulate some of these studies. The field of animal behavior may be entering a very exciting period of growth.

However, the latter words of Kutscher did not prove to be prescient (see below: "Some 21st century techniques are 40 years obsolete." Kutscher introduces the paper as follows.

In this paper Kavanau shows how experiments run under more natural conditions with freshly trapped animals can yield results quite different from those obtained with highly inbred domestic animals tested on simpler and more artificial tasks. White-footed mice learned to thread their way through a complex maze containing 427 meters of linear runways and 445 blind alleys in as little two or three days without intrinsic reward or prior deprivation. In most other experiments on maze learning the inbred white rat is motivated by hunger or thirst.

There are, of course, advantages to the use of an inbred domestic species besides the ease of procurrance and knowledge of and control over the early experience of the animals. The inbred species often show low variability on certain behavioral tasks and, indeed, are sometimes bred for these characteristics. Kavanau argues that two freshly trapped mice may respond in opposite ways to one of his tests and each could provide evidence for conflicting theories of behavior.

Kavanau's challenge to the monumental amount of research on inbred and laboratory raised species cannot be taken lightly. Each worker in the field of animal behavior must ask himself how far he wishes to generalize his data to other life forms.

Psychologist have long held the tacit assumption that the white rat was a perfectly adequate, representative life form and that principles of learning, for example, would be similar in other species, including man. The rat can be inbred to reduce behavioral variability, can be tamed, can adapt to deprivation schedules, and can produce large and frequent litters. The complacent assumption that the rat is a representative species has been questioned by Beach, but still relatively little interest has appeared in psychology on species differences.

Kavanau argues from the point of view of the biologist (ethologist and ecologist). He argues that the relatively uniform behavior of the inbred species represents only a small segment of the total response spectrum and has probably minimal significance of one wishes to generalize about the evolution and adaptedness of behavior in the wild. The ethologist's search for species differences will probably help to answer the question of how far we can generalize our data, much of which has been collected on highly inbred species.

In 1995, in their book, When Elephants Weep, authors Jeffrey M. Masson and Susan McMcarhty summarize findings from my Science review as follows:

One of the joys of freedom is surely the ability to control one's own destiny, and a few scientists have argued that animals feel the need for such control. Zoologist J. Lee Kavanau gave white-footed mice (deer mice) the opportunity to adjust light levels in their cages by pressing a lever. He found that the mice preferred dim light to bright light or darkness, and if left alone would adjust the light level accordingly.

But if he turned the lights up high the mice would frequently respond by making the cage completely dark. Conversely, if he made the cage completely dark, the mice would make the light as bright as possible. He also found that if he disturbed sleeping mice, so that they came out of their nest boxes to investigate, they would soon go back inside, but if he put them inside by hand, they would immediately come out, no matter how many times he replaced them. They cared about choice more than comfort.

When given the opportunity to manage their environment, they battled fiercely for control. Because white-footed mice have far more control over their surroundings and activities, this matters more to he captive animal. Even if a zoo animal is supplied with all material wants, there may be something vital lacking, something its need to be happy. One of the joys of freedom may simply be the ability to evade compulsion.

Additional publications in animal behavior - book chapters, etc.

1966. I contributed chapter 5 (99-146), "Automatic Monitoring of the Activities of Small Mammals," to Systems Analysis in Ecology, Edited by K. F. Watt, Academic Press, New York.

1969. I contributed a chapter, "Behavior of Captive White-Footed Mice," to Naturalistic Viewpoints in Psychological Research, Edited by E. P. Williams and H. L. Raush, Holt, Rinehart & Winston, New York.

1970. I contributed a chapter, "Behavior: Confinement, Adaptation, and Compulsory Regimes" to The Science of Psychology: Critical Reflections, Edited by D. P. Schultz, Appleton, New York.

1971. I contributed a chapter, "Behavior of captive white-footed mice" to Readings in Comparative Studies in Animal Behavior  by C. L. Kutscher, Xerox College Publications, Waltham, MA.

1979. I contributed a chapter, "Life in the Twilight Zone," to Science Year, The World Book Science Annual, World Book Childcraft International, Inc., Chicago. This well illustrated chapter covered all the studies in my laboratory and of my students in the field, up until 1979 (see below, also, the Ph.D. Thesis studies of my students).

Book Reviews by me

Theoretical and Experimental Biophysics, vol. 1, Ed. by A. Cole, Dekker, New York, 1967 (Science 1967;158:108-109).

Cell Water. By D. A. T. Dick, Butterworths, Washington, 1966.

Mammalian Cell Water, By E. G. Olmstead, Lea & Febiger, Philadelphia, 1966 (QRB 1967;42:86-87).

The State and Movement of Water in Living Organisms. Ed by G. E. Fogg, Academic Press, New York, 1965 (QRB 1967;42:87-88).

Intracellular Transport. Ed. by K. B. Warren, Academic Press, New York, 1966 (QRB 1968;43:194-195).

Membrane Models and the Formation of Biological Membranes. Ed. by L. Bolis, B. A. Pethica, North Holland, Amsterdam, 1967 (QRB 1969;44:301-302.

Biological Membranes. Physical Fact and Function. Ed. by D. Chapman, Academic Press, New York, 1968 (QRB 1969;44:341).

Biology of Peromyscus (Rodentia). Ed. by J. A. King, American Society of Mammalogists, Stillwater, 1968 (Science 1969;165:782 783).

The Molecular Basis of Membrane Function. Ed. by D. C. Tosteson, Prentice Hall, Englewood Cliffs, 1969 (QRB 1970;45:188)..

Membranes of Mitochondria and Chloroplasts. Ed by E> Racker, Van Nostrand Reinhold, New York (QRB 1970;45:288-289)

Permeability and Function of Biological Membranes. Ed. by L. Bolis, A. Katchalsky, R. D. Keynes, W. R. Loewenstein, B. A. Pethica, Oxford Univ. Press, New York, 1970 (QRB 1971;46:175-176).

Ph.D. Thesis studies of my students

1966. Morris, John Edward Chick mesonephric regression and its control.

1973. Ramos, Judith Ann - Influences of light on activity and phasing of carnivores. Judy's collaborative studies with me have been covered in the text.

1975. Rischer, Carl Edward The effects of light and temperature on the activities and phasing of small wild mammals: (Peromyscus polionotus) (Eutamias minimus) (Tamias striatus) (Ammospermophilus leucurus). Carl's collaborative laboratory studies with me have been covered in the text.

1976. LorVel Shields Telemetric determination of the activity of free-ranging rodents: the fine-structure of Microtus californicus activity patterns. LorVel.studied pack rats, California mice, and California meadow mice. He perfected a transmitter collar design by which movements and postures of the collared animals could be determined automatically. For example, changes in the spacing of pulses emitted by the transmitter indicate when the animal curls up and goes to sleep. The pulse spacing is a sensitive indicator of how snugly the transmitter is pressed against the animal's body, and this depends on the animal's position. By first observing each trapped animal in an enclosure for a time before it is released, Shields can match the pulse spacing modulations of the transmitted signal with the animal's posture and movements. When the animal is returned to its home range, its activities can be monitored in great detail.

Using antennas in a number of locations and automatic detectors, Shields noted the location, posture, and movements of one animal continuously for several weeks. When the information received was correlated with local light level, temperature, weather and seasonal changes in the type and availability of food, the animal's life became almost an open book. Shields has added greatly to our knowledge of the roles that various environmental factors play and how they influence activity patterns. Now the new knowledge he can gain about his rodents is limited primarily by his ability to deal with the vast amount of data collected.

1977. Thomas Richard Loughlin Activity patterns, habitat partitioning, and grooming behavior of the sea otter, Enhydra lutris, in California. Tom used telemetry to study the activity of sea otters living off the California coast. He discovered that researchers were wrong about an activity as basic as feeding behavior. All previous observations indicated that sea otters fed only during the day, but Loughlin proved that they do almost half their feeding at night. Tom obtained his M.A. degree in 1974 from Humboldt State University, studying the ecology and population dynamics of harbor seals.

1977. Michael Recht The biology of the Mohave ground squirrel, Spermophilus mohavensis: home range, daily activity, foraging and weight gain and thermoregulatory behavior. Mike has been using small attached radio transmitters to learn about the behavior of small mammals and lizards in the Mojave Desert in California. One of his most striking findings concerns the Mojave ground squirrel. Previous researchers had assumed that when the squirrels are not seen they are not active. Mike found that Mojave ground squirrels, by avoiding overheating can be active throughout even the hottest days. From the close inspection of behavior that radio telemetry makes feasible. He also learned that Mojave squirrels' home range expands and contracts with the available food supply. Since the animals travel over a well defined system of 'highways' to get about in their home ranges, we can now map their routes and study in detail how the squirrels use the resources of their habitat. For example, we can learn where they find water, store food and obtain their nest building materials.

1982. Fausett, Larry Lee Activity and movement patterns of the island fox, Urocyon littoralis, Baird 1857 (Carnivora, Canidae). Larry studied island foxes (Urocyon littoralis) on Santa Cruz Island, California, placing particular emphasis on determining activity and movement patterns through the use of radio telemetry. He found a lack of rhythmicity in the foxes' activity and variable times of activity, from a low of 30% in the summer to a high of 40% in the winter, with some environmental but seasonally variable influence on the time of day when activity occurs. In the summer there is very little activity during the middle of the day, but much more in the early morning and late afternoon. In the winter the reverse is true, with little activity occurring during the hours of 22:00 to 5:00. Mapping of movements showed that the ranges of different animals varied in size and area covered, both on a seasonal and sexual basis. Males covered almost twice the area of females in the winter, while both sexes had very similar size ranges in the summer.

1983. Meyers, Nancy Jean Behavioral ecology of the grasshopper mouse (Onychomys sp.): a comparative radiotelemetric investigation. Excerpts from Synopsis of Research submitted by Nancy: field study began in 1977 near Saddleback Butte in LA County, CA....behavioral data were collected with the aid of radiotelemetry....mice were fitted with collars and released at the site of capture....animals were retrapped for collar replacement....nightly activity consisted mostly of foraging which occurred intensely around bushes and the logs of fallen Joshua trees....mice traveled quickly from bush to bush....they searched under each and killed any arthropods encountered....they foraged in pairs during the breeding season....environmental parameters were recorded concurrently with behavioral data....although much new information has been gained, many questions remained unanswered.

1983. Donald Ray Perry Access methods, observations, pollination biology, bee foraging behavior, and bee community structure within a neotropical wet forest canopy. Don began his Ph.D. studies at UCLA in 1976 and focused on methods of access into the tops of tall tropical rain forest trees, also including studies of the reproductive biology of canopy plants. He devised a system of access into trees that are too weak to climb. His work has been widely published in such media as Smithsonian, Scientific American, Newsweek, Encyclopedia Britannica, International Wildlife, and Yearbook of Science and the Future. His Automated Web for Canopy Exploration won first place in the 1984 Rolex Awards for Enterprise. His 1986 book, Life above the Jungle Floor, was the basis for the film, "Medicine Man." Don's greatest achievement is his revolutionary 2007 book on human canopy evolution titled, "The Descent: The Theory of Canopy Evolution" (see www.canopyevolution.com)." He proposes that human encephalization was driven by similar, but unique, forces that lead to non human primate brain evolution, namely, those encountered in arboreal habitats.
In later years Don commented that "The freedom of thought and direction you allowed was instrumental in my continuing success." Don and I have kept in close contact, and have edited each other's works in the first years of the 21st century.

1988. Shargo, Eric Samuel Home range, movements, and activity patterns of coyotes (Canis latrans) in Los Angeles suburbs. Coyotes were studied in a suburban neighborhood from 1984to 1987. The animals were active primarily during the night. The overall activity level averaged 37.8% per day; hunting and foraging occupied only 30% of this time. A statistical analysis revealed no significant difference between the activity levels of different individuals.

Home ranges varied from 40 to 223 hectares, averaging 110. These were variable in shape and tended to follow the topography. Within each home range there were a number of foci of activity; these areas were associated with intensive foraging movements. Occupation of home ranges lasted at least several months. It is suggested that the home ranges found are consistent with expected values for omnivores.

There were seven types of movement patterns; most commonly the animals ranged between foci of activity and foraging. Cumulative distances covered during a 24-hr period averaged 5,820 m, more than 80% of this Figure during the night. The amount of time spent among suburban housing ranged from 3.9 to 100%. Animals that spent less than half of their time among housing typically limited their visits to nocturnal forays of up to 5 hr long. Animals that spent more than half their time among housing often spent the daylight hours resting on residential property. The ecological significance of influences of human activities within the study area is discussed.

1989. Hohn, Aleta Ann Variation in life-history traits: the influence of introduced variation in cetaceans. Apparent variation in life history traits, either between populations or within populations over time, may be the result of variation introduced as a by product or artifact of the process of characterizing individuals or populations rather than of natural variation. Introduced variation can occur during sampling, during measurement, or during estimation of parameters. In dolphin life history studies, a frequent source of measurement error is in estimation of age, and a frequent source of analytical error is in estimation of average age at attainment of sexual maturation (ASM). Age is generally estimated from growth layers (GLGs) in teeth. Errors occur because counting GLGs is not straightforward and incorrect assumptions about which structures represent annual layer boundaries are often made. Using Monte Carlo simulations to test four methods of estimating ASM showed that even with the same data set, differences in ASM estimates between estimators and over different sample levels. A relatively new method, the Sum of Fraction Immature method is recommended for estimating ASM.

1991. Scott, Michael David The size and structure of pelagic  dolphin herds. The study of herd size and structure of dolphins in the open ocean has been difficult. However, data collected from tuna purse seiners in the eastern Pacific Ocean have allowed such studies in some detail. An increasing trend in the proportion of mixed species herds was found with distance offshore, but even in the furthest offshore area, only 30% of the bottlenose dolphin sightings were of mixed species herds. The median herd size of 10 was similar to the typical herd sizes reported for coastal populations.

A daily pattern of increasing herd size in the morning and subsequent decline in the late afternoon or night was evident for spotted, spinner, and common dolphins, and for mixed species aggregations, as well as for the large yellowfin tuna that associate with them. Predation pressure appeared to be the major influence on this daily pattern, although the effect of prey distribution could not be discounted. Fifteen herds of Central American spinner dolphins were photographed during an aerial study off the west coast of Mexico. Computer generated maps of the herds were used to examine the spatial relationships of various size classes. Also, nearest neighbor analyses were used to examine the relationship between the size of an individual and that of its neighbors.

Michael was a scientist with the Inter American Tropical Tuna Commission, Dolphin Program both before and after his thesis studies. He authored the well known "The Tuna Dolphin Controversy" in August, 1988 in Whalewatcher.

1992. Havenhill, Roy Michael Behavior of small mammals given volitional control of illumination within an instrumented enclosure. Roy's collaborative studies with me have been covered in the text.

1992. Chivers, Susan Julia Life history parameters as indicators of density dependence for populations of delphinids. The focus of Susan's studies was to determine how several life history parameters correlated with population size relative to carrying capacity for populations of spotted, spinner, common, and striped dolphins. Identified correlations can be used as indices to distinguish between changes in population abundance responsive to changes in carrying capacity, exploitation, or recovery from exploitation.

The proportion of female dolphins that were mature and the proportion of females that were pregnant or lactating were significantly correlated with population size relative to carrying capacity for some of the species. An individual based simulation model was developed to test the assumptions of population regulatory mechanisms for marine mammals, and to predict correlations between life history parameters and population size relative to carrying capacity. Susan concluded that it is unlikely that population growth is regulated primarily by juvenile survival rates for these dolphin populations, as previously assumed.

1995. Cornish, Michael Jon Reversed sexual size dimorphism, prey selection and hunting success in five species of North American raptors. Among birds of prey that hunt other birds, the female is larger than the male, a phenomenon known as reversed sexual size dimorphism (RSD). Michael investigated the relationship between the degree of RSD, the proportion of avian prey consumed, and prey selection and hunting among 5 species of birds of prey with differing RSD. From 1985 to 1992, 301 hunts were observed by Cooper's hawks, sharp shinned hawks, prairie falcons, red tailed hawks, and red shouldered hawks during both artificially induced and naturally occurring hunts. As the RSD of a bird of prey increased, the proportion of birds it preyed upon increased, and differences in the prey taken by males and females emerged.

Red tailed and -shouldered hawks have a low to moderate RSD and both sexes preyed upon the same mammals. However, red tailed hawks generally took large prey, whereas the diet of red shouldered hawks was restricted to rodents. Cooper's hawks have a high RSD and preyed upon both birds and mammals. Differences between the sexes were noted only when birds were preyed upon. Size differences between the sexes were greatest for sharp shinned hawks, which preyed exclusively on birds and showed the greatest prey selectivity. During the winter months, prairie falcons preyed exclusively on birds.

[James Handsfield and Stacy Sjoberg successfully completed their oral preliminary examinations but were unable to complete their thesis studies for one reason or another.]

Two non-Ph.D. students who took some of my courses later became faculty in the U.C. System, one at UCLA, the other at Irvine. They eventually told me that I had been their role model.

What had began over 40 years ago as a simple question of how much sleep deer mice need led my students and me to branch out down many unexpected, exciting paths. Touching base with a variety of aspects of behavior and learning on the way, we soon found our attention focused almost exclusively on the roles light plays in the lives of animals. Several years of intensive laboratory studies of these roles inevitably raised questions that could only be answered in the field. In turn, the field studies compelled us to branch out along other unforeseen paths.

Teaching

Aside from some early teaching when I arrived at UCLA, filling in for faculty on Sabbatical, for example Ted Jahn's Advanced Cellular Physiology course, my initial teaching was in Invertebrate and Vertebrate Embryology, the latter a laboratory course. I then went on to give courses in Behavioral Research Problems (Biology 130 and 275, beginning in 1963), Mathematical Modeling (beginning in 1976), and an invited lecture course in Modern Methods in Biology. The modeling and behavior courses were very heavily populated by premedical students, most of whom successfully completed medical school and went on to a professional medical career as MDs, some in Southern California.

In all courses except the one using invited lectures it was my practice to spend the first 10 min or so discussing the latest findings in various fields of science, of interest, with special attention devoted to medicine and health. In the courses in Behavioral Research Problems and in Mathematical Modeling, I pursued the practice, not of lecturing the new material to be covered but, rather of trying to coax the material from the students, themselves. I did this by asking leading questions. No matter how obscure the material might be, in a class of 15 to 20 students, it is very likely that someone will guess correctly and, if not, further hints could be given.

It also was my practice to take student from all classes to dinner near the end of the semester or quarter. I also brought them to my home to hear my multi purpose, high fidelity sound system, complete with oscilloscopes and a spectrum analyzer to visualize all the sound waves. On these occasions, I also played their favorite recordings, for comparisons (usually borrowing them to make my own copies). In essence, these were demonstrations of the audio topics covered in coursework (recording and reproduction of sound). Sometimes I was able to bring classes to Fred Sauls' art studio in Hollywood (see Chapter 8) for lectures on the life of a highly versatile artist. I include the lengthy written comments about the sound system from one student, Kathy McClay, from May, 1976, below.

Although I'm not much of a stereo buff, I thoroughly enjoyed the session. The sound was superior to anything I'd ever heard. It was breathtaking! I found the oscilloscopes and the Lissajou Figures particularly fascinating - sat there mesmerized. The exposure to equalizers, spectrum analyzers, the Sony decoding/amplifier, rectifiers, ambient systems, cross overs, was informative and interesting. I also enjoyed learning something about different kinds of equipment (JBL speakers, Nakamichi tape system, Marantz, Sony, Audiotronics earphones). I should like to hear the system after the Dahlquists are in (also found your sculptures made from spare parts delightful, and the soundproof door panel is clever!!).

I would have liked to present, at this point, how my undergraduate and graduate students from courses responded, personally, to my teaching methods and effectiveness, by quoting directly from their most revealing course evaluations. Unfortunately, that particular file was discarded accidentally on moving from the Life Sciences Building to Slichter Hall in 2001. I have only a few scraps to draw from in this connection. These originated in other connections, as follows.

On one occasion, on June 5, 1980, just as I was in the process of finishing the text of my first geometry book, I took my class in Behavior Research Problems to dinner at an Acapulco restaurant in Westwood Village. Seven of the students wrote messages on the 10 x 14" menu which, by a stroke of luck, happened to survive at home. These are as follows.

Lee, thank you for a unique and interesting learning experience. It was fun and useful. Bill Kupfer

To a truly unique person. Good luck with your book. Arthur Maletz

Lee, I had a great time, I learned a lot, and I like your style of teaching. Good luck on your book. Steven Dominguez [Steve became an MD and my physician at UCLA. When he moved on he recommended another physician, Dr. Peter Galier, who has cared for me ever since.]

Lee, That was nice having a professor who also was a friend. Thanks for everything. Gerry

P.S. The experience with your personality and what you have to offer were enriching and valuable. Thank you. Enrique J. Gonzalez

I wish you the best of luck with your book. I hope you'll have a pleasant summer. I enjoyed the lectures on high fidelity. Fred Butler

The best of luck with your book and the years to come. Danny López.

On a very recent occasion, in 2002, I was shopping at Trader Joe's one morning. On returning to the parking lot, a former student of mine, Martha Hierro, and her son were waiting to say hello. She and her sister, Gloria, were from my Behavior Research Problems courses. Both then were practicing physicians, and she gave me their business cards. Since my fields of study in sleep, memory, and mental disorders were very different from those when they took my courses, over 20 years earlier, I sent them some recent reprints. I received a reply from Martha on July 1, as follows.

Thank you for sending me the articles on delirium and psychotic symptoms. I was so happy to see you at Trader Joe's. You look so well. Many of us who once were your students have grown and developed thanks to the professors who cared - you certainly did!!

Respectfully and sincerely, Martha Hierro,  M.D.

P.S. Maybe I will come share coffee with you sometime to discuss your work - it is intriguing!

Quite unexpectedly came an e-mail on Sept. 19, 2003, from my former student Alon Y. Avidan, who coincidentally had been invited to contribute a chapter on sleep apnea to a volume on Sleep and Aging, to which I also was an invited contributor. His pertinent communication is as follows:

"...Just about 16 years ago I was your student at UCLA....I am a neurologist & sleep specialist at the University of Michigan. You may also remember Goeff Gerstner who was also your student in the class and is also a professor at [U. of] Michigan (School of Dentistry). It is very nice to see how our paths have intersected. Last week I gave a lecture to Goeff's dental students and we were talking about our past experiences at UCLA and talked about how your class influenced our academic lives in such a positive way. You made our thinking evolve and mature and we truly miss you as a teacher. [In 2006 Alon joined the faculty of the David Geffen School of medicine at UCLA.]

[If some former student reads this material and would like to add his or her comments to a possible 2nd edition, they would be welcome-JLK.]

Some 21st century techniques are 40 years obsolete

For whatever reasons, in the years since we carried out these studies no other laboratory, to my knowledge, has followed in our footsteps, by which I mean that no other laboratory has carried out comparable, detailed, instrumented studies with state-of-the-art techniques. Automating data reduction and activating switches, today, present no problem-almost any desk computer could be programmed to accomplish it. Instrumentation for programming environmental variables and for automatic second to second monitoring to obtain data, however, present much the same challenges today as they did 50 years ago. Required are various types of naturalistic enclosures, custom built running wheels, environmental controls, electromechamical transducers, electric eyes, proximity sensors, multi channel strip chart analog and digital recorders, sensitive switches, limit switches, etc.

Not even any student of mine has carried on in this regard. As an illustrative example, to my knowledge, no one subsequently has produced a record showing time, direction, and speed of running an activity wheel on a second to second basis. Nor, apparently, have simulated twilights been employed. Even with abrupt switching between day and night conditions, the light levels being used are unfavorable (just bright and dark), if not actually damaging to the retina. It was the simulation of natural conditions that provided the substrate for our findings of the influences of twilights on animal activity, the existence of biological program clocks, etc., in many small and medium sized mammals. Do current levels of funding present insurmountable roadblocks? Is there no longer a potential for such studiest?

Pet Peeves

There were two injuries

There was one injury

There were no injuries

Regardless of possible justifications that might be advanced, it is totally illogical to revert to the plural in the last example above, when proceeding from the plural to the singular to total absence. Yet, this is essentially universal usage. I never hear anyone do otherwise but I never intentionally do so myself. "No" means total absence, and should not be used otherwise. "No fund" only sounds strange because the illogical "no funds" is in such common usage. Another favorite, "no data were," should read,, "no datum was."

Improper use of the word "temperature"

The word "temperature" does not connote a material substance. Temperatures can be high or low, rising or falling, greater than or less than, and even set records. But they cannot be hot or cold, warming, cooling, or freezing, etc. as weather forecasters would have us believe. It's the water, the wind, the ground, or collectives, such as the weather, the day, the night, etc., that are hot or cold, etc. One cannot just blame these errors on poor training of weather forecasters, because very many scientists are prone to the same error. Webster defines "temperature" as the "degree of hotness or coldness [of some material substance] measured on a definite scale." Other definitions also exist but they all incorporate references to the heat content [of a substance] in one way or another.

TV Images of athletes

In general, but most particularly for football track, and hockey players (both male and female), it is ridiculous to display them on the screen in portrait style. These images are not primarily for facial identification, in case one meets one of them on the street. They should convey the comparative physiques of the players relative to the norm. In all such cases, the full body profile of the player should be displayed against an outline of the norm, say, a 6-footer weighing about 170 pounds, for men.

Interminable chit chat among newscasters

This is the most irritating of all! Does anyone listen to newscasts to get the benefit of personal chit chat between the newscasters, as opposed to the views of news analysts? I don't think so. Yet in virtually every newscast with two or more participants, we are bombarded with endless personal exchanges between the newscasters, mostly personal comments on the last news item.. If there's more than one newscaster, please stick to the news.

We'll tell you, We'll show you, You'll see

These words are repeated endlessly by TV announcers, yet are quite superfluous. Of course, you'll tell us, you'll show us, we'll see. "Coming up" is quite enough.

Basketball

When is the game of basketball going to be restored to its original genre by raising the baskets about 2 feet? Since when is slam dunking a measure of skill (despite slam dunking contests)?