|
|
Amant, R. S., & Horton, T. E. (2008). Revisiting the definition of animal tool use. Anim. Behav., 75(4), 1199–1208.
Abstract: Benjamin Beck's definition of tool use has served the field of animal cognition well for over 25 years (Beck 1980, Animal Tool Behavior: the Use and Manufacture of Tools, New York, Garland STPM). This article proposes a new, more explanatory definition that accounts for tool use in terms of two complementary subcategories of behaviours: behaviours aimed at altering a target object by mechanical means and behaviours that mediate the flow of information between the tool user and the environment or other organisms in the environment. The conceptual foundation and implications of the new definition are contrasted with those of existing definitions, particularly Beck's. The new definition is informally evaluated with respect to a set of scenarios that highlights differences from Beck's definition as well as those of others in the literature.
|
|
|
|
Boogert, N. J., Reader, S. M., Hoppitt, W., & Laland, K. N. (2008). The origin and spread of innovations in starlings. Anim. Behav., 75(4), 1509–1518.
Abstract: There are numerous reports of novel learned behaviour patterns in animal populations, yet the factors influencing the invention and spread of these innovations remain poorly understood. Here we investigated to what extent the pattern of spread of innovations in captive groups of starlings, Sturnus vulgaris, could be predicted by knowledge of individual and social group variables, including association patterns, social rank orders, measures of neophobia and asocial learning performance. We presented small groups of starlings with a series of novel extractive foraging tasks and recorded the latency for each bird to contact and solve each task, as well as the orders of contacting and solving. We then explored which variables best predicted the observed diffusion patterns. Object neophobia and social rank measures characterized who was the first of the group to contact the novel foraging tasks, and the subsequent spread of contacting tasks was associated with latency to feed in a novel environment. Asocial learning performance, measured in isolation, predicted who was the first solver of the novel foraging tasks in each group. Association patterns did not predict the spread of solving. Contact latency and solving duration were negatively correlated, consistent with social learning underlying the spread of solving. Our findings indicate that we can improve our understanding of the diffusion dynamics of innovations in animal groups by investigating group-dependent and individual variables in combination. We introduce novel methods for exploring predictors of the origin and spread of behavioural innovations that could be widely applied.
|
|
|
|
Smith, J. E., Kolowski, J. M., Graham, K. E., Dawes, S. E., & Holekamp, K. E. (2008). Social and ecological determinants of fission-fusion dynamics in the spotted hyaena. Anim. Behav., 76(3), 619–636.
Abstract: Theory predicts that individuals living in fission-fusion societies, in which group members frequently change subgroups, should modify grouping patterns in response to varying social and environmental conditions. Spotted hyaenas, Crocuta crocuta, are long-lived carnivores that reside in permanent social groups called clans. Clans are complex, fission-fusion societies in which individual members travel, rest and forage in subgroups that frequently change composition. We studied two clans in Kenya to provide the first detailed description of fission-fusion dynamics in this species. Because social and ecological circumstances can influence the cohesiveness of animal societies, we evaluated the extent to which specific circumstances promote the formation of subgroups of various sizes. We found that cooperative defence of shared resources during interclan competition and protection from lions were cohesive forces that promoted formation of large subgroups. We also tested hypotheses suggesting factors limiting subgroup size. Mothers with small cubs avoided conspecifics, thereby reducing infanticide risk. Victims of aggression either reconciled fights or separated from former opponents to reduce the immediate costs of escalated aggression in the absence of food. As predicted by the ecological constraints hypothesis, hyaenas adjusted their grouping patterns over both short and long time scales in response to feeding competition. Crocuta were most gregarious during periods of abundant prey, joined clanmates at ephemeral kills in numbers that correlated with the energetic value of the prey and gained the most energy when foraging alone because cooperative hunting attracted numerous competitors. Overall, our findings indicate that resource limitation constrains grouping in this species.
|
|
|
|
Patris, B., Perrier, G., Schaal, B., & Coureaud, G. (2008). Early development of filial preferences in the rabbit: implications of nursing- and pheromone-induced odour learning? Anim. Behav., 76(2), 305–314.
Abstract: Newborn rabbits, Oryctolagus cuniculus, discriminate between different categories of adult conspecifics on the basis of their abdominal odour cues. Whether these cues can support the development of filial preferences has not been adequately tested. Using a two-choice paradigm, we assessed the ability of 3-8-day-old pups to orient selectively to the mother versus an unfamiliar female, either spontaneously or after odour conditioning. In experiment 1, nonconditioned pups roamed indifferently over the mother and an unfamiliar female. In experiment 2, pups conditioned to a neutral odorant while nursing or with the mammary pheromone became attracted by the odorant. In experiment 3, pups that had learned the odorant while nursing oriented for longer to any female carrying it, but the unscented mother and a scented unfamiliar female were equally attractive. Finally, in experiment 4, pups that had learned the odorant paired with the mammary pheromone showed a preference for their scented mother, but not systematically for a scented unfamiliar female; furthermore, they were equally attracted by the unscented mother and a scented unfamiliar female. In sum, pups did not spontaneously evince an olfactory preference for the mother when opposed to an unfamiliar female, although they seemed able to detect individual maternal odours. In fact, they appeared to react to both species-specific cues and individual cues that they had learned, and their responses depended on their degree of familiarity with the cues and on the context. The mammary pheromone by itself might act as both a releasing and a reinforcing signal in these early socially oriented behaviours.
|
|
|
|
Palagi, E., Antonacci, D., & Norscia, I. (2008). Peacemaking on treetops: first evidence of reconciliation from a wild prosimian (Propithecus verreauxi). Anim. Behav., 76(3), 737–747.
Abstract: Reconciliation is defined as the first postconflict affinitive contact between former opponents. While reconciliation in anthropoid primates has been widely investigated, few studies have focused on postconflict mechanisms in prosimians, and only in captivity. Unlike anthropoids, Malagasy prosimians show female dominance, lack of sexual dimorphism and seasonal breeding. However, they share features with anthropoids such as cohesive societies, female philopatry and individual recognition. Comparing social prosimians with anthropoids is crucial for understanding the evolution of reconciliation dynamics. Here we present the first study on reconciliation in a wild prosimian. We focused on the Propithecus verreauxi (sifaka) of the Berenty forest (southern Madagascar). We examined postconflict behaviour in the light of theoretical expectations based on potential costs and benefits of the individuals involved. Our results indicate that P. verreauxi can evaluate possible risks and benefits of engaging in postconflict reunions. Victims were most likely to interact affinitively with the aggressor after low-intensity aggression. Moreover, only the conflicts occurring outside the feeding context were reconciled. Such results are consonant with the fact that, in P. verreauxi, social dominance is translated more into feeding priority than into a framework of despotic relationships. In agreement with the valuable relationship hypothesis, P. verreauxi were more likely to reconcile with valuable partners: reconciliation preferentially occurred between subordinates and top-ranking individuals, and between animals sharing good relationships (high levels of affinitive behaviours). Over the short term, reconciliation in P. verreauxi seems to have an important role in reducing the probability of further attacks by the aggressor.
|
|
|
|
Griffin, A. S. (2008). Socially acquired predator avoidance: Is it just classical conditioning? Special Issue:Brain Mechanisms, Cognition and Behaviour in Birds, 76(3), 264–271.
Abstract: Associative learning theories presume the existence of a general purpose learning process, the structure of which does not mirror the demands of any particular learning problem. In contrast, learning scientists working within an Evolutionary Biology tradition believe that learning processes have been shaped by ecological demands. One potential means of exploring how ecology may have modified properties of acquisition is to use associative learning theory as a framework within which to analyse a particular learning phenomenon. Recent work has used this approach to examine whether socially transmitted predator avoidance can be conceptualised as a classical conditioning process in which a novel predator stimulus acts as a conditioned stimulus (CS) and acquires control over an avoidance response after it has become associated with alarm signals of social companions, the unconditioned stimulus (US). I review here a series of studies examining the effect of CS/US presentation timing on the likelihood of acquisition. Results suggest that socially acquired predator avoidance may be less sensitive to forward relationships than traditional classical conditioning paradigms. I make the case that socially acquired predator avoidance is an exciting novel one-trial learning paradigm that could be studied along side fear conditioning. Comparisons between social and non-social learning of danger at both the behavioural and neural level may yield a better understanding of how ecology might shape properties and mechanisms of learning.
|
|
|
|
Cameron, E. Z., Linklater, W. L., Stafford, K. J., & Minot, E. O. (2008). Maternal investment results in better foal condition through increased play behaviour in horses. Anim. Behav., 76(5), 1511–1518.
Abstract: Play behaviour is widespread in mammals, but benefits to play have been difficult to demonstrate. Physical training is one of the many proposed hypotheses, suggesting that males and females should play differently, that increased maternal investment should lead to increases in play, and that increases in play should result in physical advantages. In a population of feral horses, Equus caballus, males and females did not differ in their play behaviour except that males initiated more of their play bouts than females. Maternal condition influenced play behaviour only in males, with sons of mothers in good condition playing more. However, when we controlled for maternal effects by comparing a son and a daughter of the same mother, daughters played more when their mother was in poor condition and sons played more when their mother was in good condition. Mothers of foals that played more lost more condition. Therefore, the difference in play behaviour could not be explained by offspring sex or maternal condition alone, but play behaviour mirrored variation in maternal investment. In addition, those individuals that played more survived better and had better body condition as yearlings despite weaning earlier. Since increased activity has been linked to enhanced musculoskeletal development in domestic horses, we suggest that play provides a link between increased maternal investment, increased body condition and future reproductive success in feral horses, and probably in other species.
|
|
|
|
Udell, M. A. R., Dorey, N. R., & Wynne, C. D. L. (2008). Wolves outperform dogs in following human social cues. Anim. Behav., 76(6), 1767–1773.
Abstract: Domestic dogs, Canis familiaris, have been shown capable of finding hidden food by following pointing gestures made with different parts of the human body. However, previous studies have reported that hand-reared wolves, C. lupus, fail to locate hidden food in response to similar points in the absence of extensive training. The failure of wolves to perform this task has led to the proposal that the ability to understand others' intentions is a derived character in dogs, not present in the ancestral population (wolves). Here we show that wolves, given the right rearing environment and daily interaction with humans, can use momentary distal human pointing cues to find food without training, whereas dogs tested outdoors and dogs at an animal shelter do not follow the same human points. In line with past studies, pet dogs tested indoors were successful in following these points. We also show that the reported failure of wolves in some past studies may be due to differences in the testing environment. Our findings indicate that domestication is not a prerequisite for human-like social cognition in canids, and show the need for additional research on the role of rearing conditions and environmental factors in the development of higher-level cognitive abilities.
|
|
|
|
Brooks, C. J., & Harris, S. (2008). Directed movement and orientation across a large natural landscape by zebras, Equus burchelli antiquorum. Anim. Behav., 76(2), 277–285.
Abstract: We investigated how plains zebras moved across a large natural landscape by analysing the movement paths of nine zebra mares foraging out from spatially confined waterholes during the dry season in the Makgadikgadi Pans National Park, Botswana. Since it was essential to investigate directed movement over a range of spatial scales to determine the correct movement behaviour and strategy, we used Nams's scaling test for oriented movement. Zebras followed directed movement paths in the lower to medium spatial scales (10 m–3.7 km) and above their visual, and possibly olfactory, range. The spatial scale of directed movement suggests that zebras had a well-defined spatial awareness and cognitive ability. Seven zebras used directed movement paths, but the remaining two followed paths not significantly different to a correlated random walk (CRW). At large spatial scales (>3 km) no distinct movement pattern could be identified and paths could not be distinguished from a CRW. Foraging strategy affected the extent of directed movement: zebras with a confined dispersion of grazing patches around the central place directed their movements over a longer distance. Zebras may extend the distance at which they can direct their movement after improving their knowledge of the local environment.
|
|
|
|
Schloegl, C., Kotrschal, K., & Bugnyar, T. (2008). Modifying the object-choice task: Is the way you look important for ravens? Behav. Process., 77(1), 61–65.
Abstract: Most animals seem to have difficulties in using gaze cues to find hidden food in object-choice tasks. For instance, chimpanzees usually fail in these tests, even though they are capable of following other's gaze geometrically behind barriers. Similar to chimpanzees, common ravens are skilled in tracking other's gaze but fail in object-choice tasks. We here explored whether procedural modifications, which had been used successfully in chimpanzees, would also yield positive results in ravens. In our modifications (a) the experimenter approached the cup while gazing at it, (b) the gaze cue was accompanied by a sound and (c) the experimenter could actually see the food while giving the gaze cue. Two out of seven birds performed above chance level in some of these conditions. However, we ascribe this improvement to the individuals' learning ability rather than to an understanding of the communicative nature of the task. This interpretation is further supported by results of a follow-up experiment suggesting that ravens may not rely on conspecifics' gaze cues for finding food caches in a natural foraging context. In sum, our results suggest that ravens may not transfer their gaze follow abilities to foraging situations involving hidden food.
|
|
