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Held, S., Mendl, M., Devereux, C., & Byrne, R. W. (2001). Studies in Social Cognition: From Primates to Pigs. Animal Welfare, 10, 209–217.
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Gröschl, M., Wagner, R., Rauh, M., & Dörr, H. G. (2001). Stability of salivary steroids: the influences of storage, food and dental care. Steroids, 66(10), 737–741.
Abstract: We studied influences of dental care, food and storage on the reproducibility of salivary steroid levels. Cortisol (F), 17OH-progesterone (17OHP) and Progesterone (P) were measured using adapted commercial radioimmunoassays. Saliva samples of healthy adults (n = 15; m:8; f:7) were collected directly before and after dental care, and directly before and after breakfast with various foodstuffs. A second experiment investigated stability of steroids under different storage conditions. Four series of identical saliva portions (I: Native saliva; II: Centrifuged saliva; III: Saliva with trifluor acetate (TFA); IV: Saliva with 0.5% NaN3) were stored at room temperature and at 4°C for up to three weeks. To demonstrate influences of repeated thawing and re-freezing of saliva on steroid values, saliva samples (n = 15) were divided into identical portions. These portions were frozen and re-thawed up to 5 times before measurement. Neither dental care nor intake of bread or milk effected the reproducibility of F, 170HP, and P. Steroid levels decreased significantly in the course of three weeks under different storage conditions (P < 0.001). This decrease was clinically relevant from the second week onward, with exception of NaN3 treated samples. After repeated freezing and re-thawing 17OHP and P decreased slightly (about 5%). Only F decreased significantly after the third thawing (P < 0.001). The results show the usefulness of standardized handling of saliva samples for improving reproducibility and reliability of salivary steroid measurements.
Keywords: Cortisol; 17OH-Progesterone; Progesterone; Saliva; Stability
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Xitco, M., Gory, J., & Kuczaj, S. (2001). Spontaneous pointing by bottlenose dolphins (Tursiops truncatus). Anim. Cogn., 4(2), 115–123.
Abstract: Two bottlenose dolphins (Tursiops truncatus) participating in a symbolic communication project spontaneously developed behaviors that resembled pointing and gaze alternation. The dolphins' behavior demonstrated several features reminiscent of referential communicative behavior. It was triadic, involving a signaler, receiver, and referent. It was also indicative, specifying a focus of attention. The dolphins' points were distinct from the act of attending to or acting on objects. Spontaneous dolphin pointing was influenced by the presence of a potential receiver, and the distance between that receiver and the dolphin. These findings suggest that dolphins are capable of producing referential gestures.
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López, J., Gómez, Y., Rodríguez, F., Broglio, C., Vargas, J., & Salas, C. (2001). Spatial learning in turtles. Anim. Cogn., 4(1), 49–59.
Abstract: Turtles (Pseudemys scripta) were trained in place, cue and control open-field procedures. The turtles trained in both the place and the cue procedures were able to learn their respective tasks with accuracy. Subsequent probe tests revealed that the turtles trained in the place task relied on the information provided by the extramaze cues to locate the goal. However, for these animals, no single cue was essential for performance, as accurate navigation to the goal was still possible when subsets of extramaze cues were eliminated. Furthermore, the turtles trained in the place task were able to navigate accurately to the goal place from new start locations. These results suggest that the turtles trained in the place task used map-like, relational strategies, by encoding the simultaneous spatial relationships between the goal and the extramaze cues in an allocentric frame of reference. In contrast, the turtles trained in the cue procedure used guidance strategies, i.e. approaching the individual intramaze cue associated to the goal as it were a beacon and largely ignoring the extramaze cues. Thus, the results of this experiment suggest that turtles are able to employ spatial strategies that closely parallel those described in mammals and birds.
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Arthur, D., & Levin, E. (2001). Spatial and non-spatial visual discrimination learning in zebrafish (Danio rerio). Anim. Cogn., 4(2), 125–131.
Abstract: Zebrafish (Danio rerio) provide an excellent model for assessment of molecular processes of neurodevelopment. To determine the functional importance of molecular events during neurodevelopment, we have developed methods for assessing learning in zebrafish in a three-chambered fish tank. In the first study, simple escape response was assessed. Zebrafish tested with a moving net learned to escape to another chamber more rapidly over the six sessions of training than the fish with the still net which did not learn. Upon reversal of the contingencies, the fish switched to the inactive net rapidly learned to suppress the escape response and fish formerly in the inactive net condition learned to avoid the moving net. In the second study, spatial discrimination learning was assessed. Zebrafish were trained on a right-left position discrimination to avoid the active net. Zebrafish showed significant improvement in escape responses over six sessions of training with three trials per session. In the third study, red-blue non-spatial discrimination learning was assessed. There was a significant improvement over the first six training sessions. With the reversal of contingencies, there was a significant decline of performance. With continued training, the fish again significantly improved avoidance. These studies found an effective motivational stimulus and procedure for studying escape behavior in zebrafish; a procedure whereby zebrafish would learn both spatial and non-spatial discrimination. These methods are being developed to help determine the functional importance of molecular events during zebrafish neurodevelopment.
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Webster, S., & Fiorito, G. (2001). Socially guided behaviour in non-insect invertebrates. Anim. Cogn., 4(2), 69–79.
Abstract: A review of the past 50 years of literature on socially guided behaviour addresses two questions: (1) whether socially guided behaviour, which has traditionally been considered characteristic of vertebrates, is also found among non-insect invertebrates, and (2) to see whether our classification of socially guided behaviours in invertebrates matches, and thereby supports, A. Whiten and R. Ham's classification of vertebrate behaviours into two broad categories, social learning and social influence. We systematically reviewed the literature on socially guided behaviour in non-insect invertebrates to determine if social behaviours exist. Once this was established, we characterised our findings using 13 behavioural phenomena that are considered to be descriptive of socially guided behaviour. Using a multivariate technique, we then analysed the data to determine if our characterisation scheme produced a similar distribution to that presented by A. Whiten and R. Ham. Our results indicate that socially guided behaviours are present in invertebrates, and invertebrates can be placed into the previously established framework on vertebrate social behaviour. Further, our analysis reveals a prominent separation between representations of the social influence and social learning categories, thereby supporting the previously published framework on socially guided behaviour.
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Snowdon, C. T. (2001). Social processes in communication and cognition in callitrichid monkeys: a review. Anim. Cogn., 4(3), 247–257.
Abstract: Studies of vocal development in nonhuman primates have found little evidence for plasticity in vocal production, somewhat more for usage of calls, with the greatest plasticity arising in response to calls of others. Generally, similar results were obtained with callitrichid monkeys, the marmosets and tamarins, but with several interesting exceptions. Infant pygmy marmosets show babbling behavior with improvement in adult call structure related to the amount and diversity of babbling. Adult marmosets alter call structure in response to changes in social partners, and wild marmosets have vocal dialects and modify call structure according to how far they are from other group members, suggesting the potential to modify call structure in different social and environmental contexts, though direct learning of novel vocalizations has not been observed. Infant cotton-top tamarins do not produce adult-like calls in appropriate contexts, at least in the first few months of life, but through food sharing from adults infants learn about appropriate foods and the appropriate contexts for food vocalizations. Tamarins modify call structure and usage with changes in social status. Tamarins, unlike other monkeys tested, can learn to avoid noxious foods through observation of other group members, and can learn about novel food locations. Recent studies provide evidence of contextual imitation in marmosets. The plasticity in vocal communication and evidence of social learning in marmosets and tamarins relative to other monkeys may be related to the cooperative breeding system of marmosets and tamarins. With a high degree of behavioral coordination among group members, there is a priority on monitoring signals and behavior of others and adjusting one's own signals and behavior. This creates the context for vocal plasticity and social learning.
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Bahloul, K., Pereladova, O. B., Soldatova, N., Fisenko, G., Sidorenko, E., & Sempere, A. J. (2001). Social organization and dispersion of introduced kulans (Equus hemionus kulan) and Przewalski horses (Equus przewalski) in the Bukhara Reserve, Uzbekistan. J. Arid. Environ., 47(3), 309–323.
Abstract: Asiatic wild asses and Przewalski horses initially inhabited steppe, semi-desert and desert areas, but Przewalski horses became extinct in the wild, and kulans disappeared at the beginning of the 20th century, except for a small population in Turkmenistan. The Bukhara Breeding Centre (Uzbekistan) was created in 1976 for reintroduction and conservation of wild ungulate species. In 1977-1978, five kulans (two males and three females), from Barsa-Kelmes island on the Aral sea, were introduced into the reserve. The group increased to 25-30 animals in 1989-1990, when eight Przewalski horses from Moscow and St Petersburg zoos were introduced. We analysed the home ranges, preferred habitats and social interactions of these closely related species during 1995-1998 by seasonal and group composition. Horses and asses formed a reproductive group and a secondary non-reproductive group. The home range of the secondary group was larger than the reproductive group and seemed to be less dependent from the watering places. Przewalski horses were less adapted to semi-desert conditions (both water and vegetation needs) than kulan.
Keywords: Przewalski horses; kulans; Central Asia; home range; behaviour
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Pongrácz, P., Miklósi, Á., Kubinyi, E., Gurobi, K., Topál, J., & Csányi, V. (2001). Social learning in dogs: the effect of a human demonstrator on the performance of dogs in a detour task. Anim. Behav., 62(6), 1109–1117.
Abstract: We recorded the behaviour of dogs in detour tests, in which an object (a favourite toy) or food was placed behind a V-shaped fence. Dogs were able to master this task; however, they did it more easily when they started from within the fence with the object placed outside it. Repeated detours starting from within the fence did not help the dogs to obtain the object more quickly if in a subsequent trial they started outside the fence with the object placed inside it. While six trials were not enough for the dogs to show significant improvement on their own in detouring the fence from outside, demonstration of this action by humans significantly improved the dogs' performance within two-three trials. Owners and strangers were equally effective as demonstrators. Our experiments show that dogs are able to rely on information provided by human action when confronted with a new task. While they did not copy the exact path of the human demonstrator, they easily adopted the detour behaviour shown by humans to reach their goal.
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Galef BG, J., & Giraldeau, L. A. (2001). Social influences on foraging in vertebrates: causal mechanisms and adaptive functions. Anim. Behav., 61(1), 3–15.
Abstract: We summarize 20 years of empirical and theoretical research on causes and functions of social influences on foraging by animals. We consider separately studies of social influence on when, where, what and how to eat. Implicit in discussion of the majority of studies is our assumption that social influences on foraging reflect a biasing of individual learning processes by social stimuli rather than action of independent social-learning mechanisms. Our review of theoretical approaches suggests that the majority of formally derived hypotheses concerning functions of social influence on foraging have not yet been tested adequately and many models are in need of further refinement. We also consider the importance to the future of the field of integrating 'top-down' and 'bottom-up' approaches to the study of social learning. Copyright 2001 The Association for the Study of Animal Behaviour.
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