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Giraldeau, L. A., & Beauchamp, G. (1999). Food exploitation: searching for the optimal joining policy. Trends In Ecology And Evolution, 14(3), 102–106.
Abstract: Commonly invoked foraging advantages of group membership include increased mean food intake rates and/or reduced variance in foraging success. These foraging advantages rely on the occurrence of 'joining': feeding from food discovered or captured by others. Joining occurs in most social species but the assumptions underlying its analysis have been clarified only recently, giving rise to two classes of model: information-sharing and producer-scrounger models. Recent experimental evidence suggests that joining in ground-feeding birds might be best analysed as a producer-scrounger game, with some intriguing consequences for the spatial distribution of foragers and patch exploitation.
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Boysen, S. T., & Himes, G. T. (1999). Current Issues And Emerging Theories In Animal Cognition. Annual Review of Psychology, 50(1), 683–705.
Abstract: Comparative cognition is an emerging interdisciplinary field with contributions from comparative psychology, cognitive/experimental and developmental psychology, animal learning, and ethology, and is poised to move toward greater understanding of animal and human information-processing, reasoning, memory, and the phylogenetic emergence of mind. This chapter highlights some current issues and discusses four areas within comparative cognition that are yielding new approaches and hypotheses for studying basic conceptual capacities in nonhuman species. These include studies of imitation, tool use, mirror self-recognition, and the potential for attribution of mental states by nonhuman animals. Though a very old question in psychology, the study of imitation continues to provide new avenues for examining the complex relationships among and between the levels of imitative behaviors exhibited by many species. Similarly, recent work in animal tool use, mirror self-recognition (with all its contentious issues), and recent attempts to empirically study the potential for attributional capacities in nonhumans, all continue to provide fresh insights and novel paradigms for addressing the defining characteristics of these complex phenomena.
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Erhart, E., & Overdorff, D. (1999). Female Coordination of Group Travel in Wild Propithecus and Eulemur. Int. J. Primatol., 20(6), 927-940.
Abstract: Coordination of primate group movements by individual group members is generally categorized as leadership behavior, which entails several steps: deciding where to move next, initiating travel, and leading a group between food, water sources, and rest sites. Presumably, leaders are able to influence their daily foraging efficiency and nutritional intake, which could influence an individual's feeding ecology and long-term reproductive success. Within anthropoid species, females lead group movements in most female-bonded groups, while males lead groups in most nonfemale-bonded groups. Group leadership has not been described for social prosimians, which are typically not female-bonded. We describe group movements in two nonfemale-bonded, lemurid species living in southeastern Madagascar, Propithecus diadema edwardsi and Eulemur fulvus rufus. Although several social lemurids exhibit female dominance Eulemur fulvus rufus does not, and evidence for female dominance is equivocal in Propithecus diadema edwardsi. Given the ecological stresses that females face during reproduction, we predict that females in these two species will implement alternative behavioral strategies such as group leadership in conjunction with, or in the absence of, dominance interactions to improve access to food. We found that females in both species initiated and led group movements significantly more often than males did. In groups with multiple females, one female was primarily responsible for initiating and leading group movements. We conclude that female nutritional needs may determine ranging behavior to a large extent in these prosimian species, at least during months of gestation and lactation.
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Walker, E. P., & Nowak, R. M. (1999). Walker's Mammals of the World.
Abstract: Description
From reviews of previous editions: “Professional naturalists will find [these volumes] invaluable as a handy reference, and amateurs at least those citizens alive to their earthly environment should delight in finding so much fascinating information made so available and palatable. Audubon ”What an amazing lot mammals are, seen here in all of their diversity! . . . Walker has made available a mine of information, for the specialist as well as for the casually interested . . . If you want to find out about a mammal, then, here is the place to look.“New York Times ”Every mammalogist must have [these books], and those who profess a broad interest in the fauna of the world will want them.“Natural History From aardwolves and bandicoots to yapoks and zorillas, Ernest P. Walker's Mammals of the World is the most comprehensive the pre-eminent reference work on mammals. Now, completely revised and updated, this fascinating guide is better than ever. Providing a complete account of every genus of mammal in all historical time, the sixth edition is 25 percent longer than its predecessor. Of the previous generic accounts, 95 percent have been substantively modified, and there are 80 new ones among them, three remarkable, large ungulates recently discovered in the forests of Indochina. New also is a full account of the woolly mammoth, now known to have survived until less than 4,000 years ago. Each section of the book describes one genus and includes facts such as scientific and common names, the number and distribution of species, measurements and physical traits, habitat, locomotion, daily and seasonal activity, population dynamics, home range, social life, reproduction, and longevity. Textual summaries present accurate, well-documented descriptions of the physical characteristics and living habits of mammals in every part of the world. As in the last two editions, the names and distributions of every species of every genus are listed in systematic order. These lists have now been cross-checked to ensure coverage of all species in the comprehensive new Smithsonian guide, Mammal Species of the World. Facts on the biology of mammals have been brought together from more than 2,700 newly cited references, nearly all published in the last decade. Also new are the latest data on reproduction, longevity, fur harvests, numbers in the wild and in captivity, and conservation status. The sixth edition also records all official classifications of every mammal species and subspecies in the massive 1996 IUCN Red List of Threatened Animals. The illustrations more than 1,700 include virtually every genus of mammal. Among them are pictures by such noted wildlife photographers as Leonard Lee Rue III, Bernhard Grzimek, David Pye, and Warren T. Houck. Mammals pictured here for the first time include the just-discovered giant muntjac deer of Viet Nam, a rodent known only from the Solomon Islands, a large fruit bat whose male suckles the young, and an extremely rare web-footed tenrec of Madagascar. Since its publication in 1964, Walker's Mammals of the World has become a favorite guide to the natural world for general readers as well as an invaluable resource for professionals. This sixth edition represents more than half a century of scholarship? Ernest P. Walker himself devoted more than thirty years to the original project and remains true to Walker's vision, smoothly combining thorough scholarship with a popular, readable style to preserve and enhance what the Washington Post called ”a landmark of zoological literature."
Reviews
“"An absolute treasure trove--a 'must' for the working naturalist as well as for any person who has curiosity about the world's mammals.”Roger Tory Peterson."?
“Unlike many academic reference works, all editions [Walker's Mammals], the new one included, are as accessible to amateurs as to professionals . . . For wildlife enthusiasts, this two-volume set is an indispensable resource. The new edition not only updates taxonomic information generated in the last 10 years, it pushes back the historical record, including all mammals known to have existed in the past 5,000 years. Twenty-one new genera also appear, animals that have recently been discovered. Either volume is hefty enough to kill a small mammal if dropped there's a total of 2,160 pages . . . And despite almost a decade between editions the last edition appeared in 1991 the price has remained virtually the same, despite an increase in book size of more than 20 percent. After being exposed to this kind of thorough, detailed information saturation, many readers may find it hard to go back to a plain old encyclopedia for their animal questions.”Bloomsbury Review
“For anyone who needs an up-to-date, comprehensive guide to every known species of mammal, Walker's Mammals of the World is an essential purchase.”Nicholas Gould, International Zoo News
“A massive compilation ideal for readers who want to have at their fingertips information on every mammal species.”International Zoo News
Author Information
Ernest P. Walker (1891-1969) began work on Mammals of the World in the early 1930s, when he became assistant director of the National Zoo in Washington. His work reflected an unequaled store of knowledge about the world's mammals. Ronald M. Nowak was senior author of the fourth edition and author of the fifth edition of Walker's Mammals of the World. His other works on mammalogy include North American Quaternary Canis and several parts of the National Geographic Society's Wild Animals of North America, for which he also was editorial consultant. He received a Ph.D. in biology from the University of Kansas in 1973 and was staff mammalogist at the former Office of Endangered Species, U.S. Fish and Wildlife Service, from 1974 to 1987. He served as an Air Force officer for four years and is a private pilot.
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Goodwin, D. (1999). The importance of ethology in understanding the behaviour of the horse. Equine Vet J Suppl, (28), 15–19.
Abstract: Domestication has provided the horse with food, shelter, veterinary care and protection, allowing individuals an increased chance of survival. However, the restriction of movement, limited breeding opportunities and a requirement to expend energy, for the benefit of another species, conflict with the evolutionary processes which shaped the behaviour of its predecessors. The behaviour of the horse is defined by its niche as a social prey species but many of the traits which ensured the survival of its ancestors are difficult to accommodate in the domestic environment. There has been a long association between horses and man and many features of equine behaviour suggest a predisposition to interspecific cooperation. However, the importance of dominance in human understanding of social systems has tended to overemphasize its importance in the human-horse relationship. The evolving horse-human relationship from predation to companionship, has resulted in serial conflicts of interest for equine and human participants. Only by understanding the nature and origin of these conflicts can ethologists encourage equine management practices which minimise deleterious effects on the behaviour of the horse.
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Macuda, T., & Timney, B. (1999). Luminance and chromatic discrimination in the horse (Equus caballus). Behav. Process., 44(3), 301–307.
Abstract: Equine colour vision was measured under conditions that minimised the possibility of animals using brightness cues to make chromatic discriminations. In a two-stage study, we first obtained luminance discrimination functions for achromatic targets then tested for chromatic discrimination over a range of target luminances. Horses were trained on a two-choice discrimination task. The positive stimulus was varied in luminance and/or colour using neutral density and broad band colour filters. The negative stimulus appeared as a uniform grey. In the brightness discrimination task, the horses performed well at large luminance differences but their percentage of correct responses declined to near chance levels at differences of less than 0.2 log units. In addition, a decrement in performance was noted at luminance differences of less than 0.2 log units for green and yellow chromatic discrimination functions, suggesting that horses cannot easily discriminate yellow and green from grey. However, the chromatic discrimination functions for red and blue showed that animals performed very well across the full range of target luminances. These results suggest that horses are at least dichromats.
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Linklater, W. L., Cameron, E. Z., Minot, E. O., & Stafford, K. J. (1999). Stallion harassment and the mating system of horses. Anim. Behav., 58(2), 295–306.
Abstract: Feral horse, Equus caballus, breeding groups, called bands, usually include one but sometimes up to five stallions. We found that mares were loyal to single-stallion (SS) or multistallion (MS) bands or were social dispersers (maverick mares, Mv). The spacing and social behaviour of mares and stallions in single- and multistallion bands was measured. Indices of mare well-being were also measured including activity budgets (feeding: MS>SS=Mv; resting: MS<SS=Mv), band and mare travel (MS>SS), maternal effort in maintaining contact with foals (MS=Mv>SS), parasite levels in faeces (MS>Mv>SS), body condition (MS=Mv<SS), fecundity (Mv<MS<SS) and offspring mortality (Mv<MS<SS). We present evidence suggesting that the poorer well-being of maverick mares and multistallion band mares results from greater harassment by stallions. Stallion and mare behaviour and poor reproductive success in multistallion bands were not consistent with explanations for the existence of such bands based on cooperation or alternative mating strategies. We suggest an alternative explanation. Stable relationships between mares and a single stallion may enhance reproductive success by reducing aggression between individuals. Therefore, we propose that there is strong selection pressure for stable, long-term stallion-mare relationships, called consort relationships. We propose the consort hypothesis, that multistallion bands are an artefact of selection for stable relationships that occasionally result in more than one such relationship forming, because mares solicit more than one stallion and stallion dominance changes during band formation. Copyright 1999 The Association for the Study of Animal Behaviour.
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Smith, S., & Goldman, L. (1999). Color discrimination in horses. Appl. Anim. Behav. Sci., 62(1), 13–25.
Abstract: Four Arabian horses and one Thoroughbred were presented with a series of two-choice color vs. gray discrimination problems. Testing was done in a stall containing a wall with two translucent panels that were illuminated from behind by light projected through color or gray filters to provide the discriminative stimuli. Horses first learned to push one of the panels in order to receive the food reward behind the positive stimulus in an achromatic light-dark discrimination task, and were then tested on their ability to discriminate between gray and four individual colors: red (617 nm), yellow (581 nm), green (538 nm), and blue (470 nm). The criterion for learning was set at 85% correct responses, and final testing for all color vs. gray discriminations involved grays of varying intensities, making brightness an irrelevant cue. Three subjects were tested with all four colors. Two of those subjects successfully reached the criterion for learning on all four color vs. gray discriminations, while the third reached criterion with red and blue, but performed at chance levels for yellow and green. A fourth horse was only tested with green and yellow, and a fifth only with blue, and both of those horses successfully reached criterion on the discriminations they attempted. With the exception of the one subject's poor performance with yellow and green, there was no significant difference between horses on any of the discrimination tasks, and no significant difference in their performance with different colors. The results suggest that horses have color vision that is at least dichromatic, although partial color-blindness may occur in some individuals.
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Clayton, H. M., Lanovaz, J. L., Schamhardt, H. C., & van Wessum, R. (1999). The effects of a rider's mass on ground reaction forces and fetlock kinematics at the trot. Equine Vet J Suppl, 30, 218–221.
Abstract: Ground reaction force (GRF) measurements are often normalised to body mass to facilitate inter-individual comparisons. The objective of this study was to explore the effect of a rider on the GRFs and fetlock joint kinematics of trotting horses. The subjects were 5 dressage-trained horses and 3 experienced dressage riders. Ground reaction force measurements and sagittal view videotapes were recorded as the horses trotted at the same velocity in hand (3.49 +/- 0.52 m/s) and with a rider (3.49 +/- 0.46 m/s). Data were time-normalised to stance duration. Ground reaction force measurements were expressed in absolute terms and normalised to the system mass (horse or horse plus rider). All the horses showed changes in the same direction when comparing the ridden condition with the in-hand condition. There was an increase in the absolute peak vertical GRFs of the fore- and hindlimbs with a rider. However, the mass-normalised peak vertical GRFs were lower for the ridden condition, with the peak occurring later in the forelimbs and earlier in the hindlimbs compared with the inhand condition. Maximal fetlock angle and its time of occurrence were similar for the 2 conditions, but the fore fetlock joint was more extended during the later part of the stance phase in ridden horses. The presence of a rider appeared to affect the GRFs and fetlock joint kinematics differently in the fore- and hindlimbs, and the ridden horse did not seem to be equivalent to a proportionately larger horse. This should be considered when normalising for body mass in studies comparing horses in hand and ridden horses.
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Aureli, F., Preston, S. D., & de Waal, F. B. (1999). Heart rate responses to social interactions in free-moving rhesus macaques (Macaca mulatta): a pilot study. J Comp Psychol, 113(1), 59–65.
Abstract: Heart rate telemetry was explored as a means to access animal emotion during social interactions under naturalistic conditions. Heart rates of 2 middle-ranking adult females living in a large group of rhesus macaques (Macaca mulatta) were recorded along with their behavior. Heart rate changes during 2 types of interactions were investigated, while controlling for the effects of posture and activity. The risk of aggression associated with the approach of a dominant individual was expected to provoke anxiety in the approachee. This prediction was supported by the heart rate increase after such an approach. No increase was found when the approacher was a kin or a subordinate individual. The tension-reduction function of allogrooming was also supported. Heart rate decelerated faster during the receipt of grooming than in matched control periods.
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