| Home | [1–10] << 11 12 13 14 15 16 17 18 19 20 >> [21–27] |
|
Kralj-Fiser, S., Scheiber, I. B. R., Blejec, A., Moestl, E., & Kotrschal, K. (2007). Individualities in a flock of free-roaming greylag geese: behavioral and physiological consistency over time and across situations. Horm Behav, 51(2), 239–248.
Abstract: The concept of personality implies individual differences in behavior and physiology that show some degree of repeatability/consistency over time and across contexts. Most studies of animal personality, particularly studies of individuals' variation in physiological mechanisms, have been conducted on selected individuals in controlled conditions. We attempted to detect consistent behaviors as well as physiological patterns in greylag ganders (Anser anser) from a free-roaming flock living in semi-natural conditions. We tested 10 individuals repeatedly, in a handling trial, resembling tests for characterization of “temperaments” in captive animals. We recorded the behavior of the same 10 individuals during four situations in the socially intact flock: (1) a “low density feeding condition”, (2) a “high density feeding condition”, (3) a “low density post-feeding situation” and (4) while the geese rested. We collected fecal samples for determination of excreted immuno-reactive corticosterone (BM) and testosterone metabolites (TM) after handling trials, as well as the “low density feeding” and the “high density feeding” conditions. BM levels were very highly consistent over the repeats of handling trials, and the “low density feeding condition” and tended to be consistent over the first two repeats of the “high density feeding condition”. Also, BM responses tended to be consistent across contexts. Despite seasonal variation, there tended to be inter-test consistency of TM, which pointed to some individual differences in TM as well. Aggressiveness turned out to be a highly repeatable trait, which was consistent across social situations, and tended to correlate with an individual's resistance during handling trials. Also, “proximity to the female partner” and “sociability” – the average number of neighboring geese in a close distance while resting – were consistent. We conclude that aggressiveness, “affiliative tendencies” and levels of excreted corticosterone and testosterone metabolites may be crucial factors of personality in geese.
|
|
Taillon, J., & Cote, S. D. (2007). Social rank and winter forage quality affect aggressiveness in white-tailed deer fawns. Anim. Behav., 74(2), 265–275.
Abstract: Achieving a high social rank may be advantageous for individuals at high population densities, because dominance status may determine the priority of access to limited resources and reduce individual loss of body mass. The establishment of dominance relationships between individuals involves variable levels of aggressiveness that can be influenced by resource availability. The relationship between social rank and aggressiveness and the impacts of resource abundance on aggressiveness are, however, poorly understood, but may be relevant to understand the mechanisms determining dominance relationships between individuals. We experimentally simulated, in seminatural enclosures, a deterioration of winter forage quality induced by a high-density deer population and examined the effects of (1) social dominance and (2) diet quality on aggressiveness, forage intake and body mass loss of white-tailed deer, Odocoileus virginianus, fawns during two winters. Within diet-quality treatments, fawns were consistently organized into linear hierarchies and showed clear dominance relationships. Dominants initiated more interactions and showed higher aggressiveness than subordinates, but subordinates had higher forage intake than dominants throughout winter. Social rank did not influence cumulative body mass loss of fawns. During both winters, fawns fed the control diet maintained their aggressiveness level, whereas fawns fed the poor-quality diet decreased it. Our experimental approach revealed that white-tailed deer responded to a reduction in winter forage quality by modifying their aggressiveness, indicating that ungulates may show plasticity not only in their foraging behaviour in response to decreased resources but also in their social behaviour.
|
|
Bonnie, K. E., & Earley, R. L. (2007). Expanding the scope for social information use. Anim. Behav., 74(2), 171–18.
Abstract: Our understanding of how, why, and the circumstances under which animals use social information has been facilitated by three principal areas of research, social learning, public information use and social eavesdropping. With few exceptions, these related concepts have remained remarkably distinct within the literature, with little discussion or integration among them. Are these distinctions warranted? We tackle the issue by exploring similarities and differences between the concepts with respect to how animals gather and use social information, the type of information gathered, how information is packaged, and the relative payoffs to individuals involved. We contend that none of the currently dominant paradigms, social learning, public information use, or social eavesdropping, provide a unifying theme for studying social information use. Instead, we favour the central characteristic of the three concepts, social information use, as the overarching umbrella, and advocate a broader conceptual framework for understanding more comprehensively how animals behave with their social environments. Our intention is not to revolutionize the fields of social learning, public information use or social eavesdropping, but rather to stimulate discussion among researchers investigating the abilities of animals to extract information from the social environment.
|
|
Hattori, Y., Kuroshima, H., & Fujita, K. (2007). I know you are not looking at me: capuchin monkeys` ? (Cebus apella) sensitivity to human attentional states. Anim. Cogn., 10(2), 141–148.
Abstract: Abstract The present study asked whether capuchin monkeys recognize human attentional states. The monkeys requested food from the experimenter by extending an arm (pointing) toward the baited one of two transparent cups. On regular trials the experimenter gave the food immediately to the monkeys upon pointing but on randomly inserted test trials she ignored the pointing for 5 s during which she displayed different attentional states. The monkeys looked at the experimenter's face longer when she looked at the monkeys than when she looked at the ceiling in Experiment 1, and longer when she oriented her head midway between the two cups with eyes open than when she did so with eyes closed in Experiment 2. However, the monkeys showed no differential pointing in these conditions. These results suggest that capuchins are sensitive to eye direction but this sensitivity does not lead to differential pointing trained in laboratory experiments. Furthermore, to our knowledge, this is the first firm behavioral evidence that non-human primates attend to the subtle states of eyes in a food requesting task.
|
|
Voelkl, B., & Huber, L. (2007). Common marmosets (Callithrix jacchus) do not utilize social information in three simultaneous social foraging tasks. Anim. Cogn., 10(2), 149–158.
Abstract: Abstract Social foraging is suggested to increase foraging efficiency, as individuals might benefit from public information acquired by monitoring the foraging activities of other group members. We conducted a series experiments with captive common marmosets (Callithrix jacchus) to investigate to what extent marmosets utilize social information about food location when foraging simultaneously with conspecifics. Subjects were confronted with dominant and subordinate demonstrators in three experiments which differed in the amount of information about food location available to the demonstrators. In all three experiments, the focal subjects` performance in the social condition was not enhanced in comparison to a non-social control condition. Because we could rule out kleptoparasitism and aggressive displacements as explanations, we argue that the subjects tendency for scramble competition by avoiding others and dispersing over the foraging area seems to inhibit or mask the acquisition of social information about the location of rewarded patches.
|
|
Harris, P. A. (2007). How should we feed horses – and how many times a day? The Veterinary Journal, 173(2), 252–253.
|
|
Scordato, E. S., & Drea, C. M. (2007). Scents and sensibility: information content of olfactory signals in the ringtailed lemur, Lemur catta. Anim. Behav., 73(2), 301–314.
Abstract: The function of olfactory signalling in social species is less well understood than in asocial species. Consequently, we examined olfactory communication in the ringtailed lemur, a socially complex primate that retains a functional vomeronasal organ, has well-developed scent glands and shows a suite of scent-marking behaviour. To assess the information content of different types of scent gland secretions, we decoupled olfactory cues from the visual and behavioural modalities with which scent marking is normally associated. We presented male and female subjects (signal receivers) with a series of choice tests between odours derived from conspecific donors (signal senders) varying by sex, age, social status and reproductive condition. We additionally examined the influence of the receivers' reproductive state and familiarity with the signaller. The reproductive condition, social status and familiarity of senders and receivers affected signal transmission; specifically, male receivers attended most to the odours of conspecifics in breeding condition and to the odours of familiar, dominant animals. By contrast, females varied their responses according to both their own reproductive state and that of the sender. Based on male and female patterns of countermarking, we suggest that scent marking serves a function in intergroup spacing and intrasexual competition for both sexes, as might be expected in a female-dominant species. By contrast, minimal female interest in male odours counters a female mate choice function for scent marking in this species. Nevertheless, scent marks are critical to male-male competition and, therefore, may be subject to sexual selection.
|
|
Li, C., Jiang, Z., Tang, S., & Zeng, Y. (2007). Influence of enclosure size and animal density on fecal cortisol concentration and aggression in Pere David's deer stags. Gen Comp Endocrinol, 151(2), 202–209.
Abstract: We investigated the impact of enclosure size and animal density on behavior and adrenocortical secretion in Pere David's deer in Dafeng Nature Reserve, China. From February 15 to April 16 in 2004, we conducted two experiments. First, we studied maintenance behavior and conflict behavior of Pere David's deer stags in a large enclosure (200 ha) with low animal density (0.66 deer/ha) and a small display pen (0.75 ha) with high animal density (25.33 deer/ha). The maintenance behavior we recorded included standing, locomotion, foraging and rest. During the behavioral observations, we collected fresh voided fecal samples from the stags periodically, and analyzed the fecal cortisol concentrations in those samples using radioimmunoassay technique. Second, we monitored the fecal cortisol concentrations of one group of stags (12 deer lived in an enclosure of 100 ha) before and after transferred into a small pen (0.5 ha). We found that in the first experiment: (1) there were significant differences in standing and rest whereas no significant differences of locomotion and foraging between the free-ranging group and the display group; (2) frequency of conflict behavior in the display group was significantly higher than those in the free-ranging group; and (3) fecal cortisol concentration of the display group (326.17+/-16.98 ng/g dry feces) was significantly higher than that of the free-ranging group (268.98+/-15.21 ng/g dry feces). In the second experiment, there was no significant difference of the fecal cortisol concentrations among sampling days, but the mean fecal cortisol concentration of the day after transferring (337.46+/-17.88 ng/g dry feces) was significantly higher than that of the day before transferring (248.44+/-7.99 ng/g dry feces). Comparison with published findings, our results indicated that enclosure size and animal density affect not only behaviors, but also adrenocortical secretion in Pere David's deer. Small living space with high animal density may impose physiological stress to captive Pere David's deer. Moreover, long-term physiological stress and increase of conflict behavior may subsequently affect survival and reproduction of the deer.
|
|
Schino, G., di Sorrentino, E. P., & Tiddi, B. (2007). Grooming and coalitions in Japanese macaques (<em>Macaca fuscata</em>): Partner choice and the time frame reciprocation. Journal of Comparative Psychology, 121(2), 181–188.
Abstract: Evidence of a reciprocal exchange of grooming and agonistic support in primates is mixed. In this study, the authors analyzed a large database of grooming and coalitions in captive female Japanese macaques (Macaca fuscata) to investigate their within-group distribution and temporal relations. Macaques groomed preferentially those individuals that groomed them most and supported preferentially those individuals that supported them most. They also supported preferentially those individuals that groomed them most and groomed preferentially those individuals that supported them most. These results were not explained by covariation of grooming and support with third variables such as kinship, rank, or time spent in proximity. However, receiving grooming did not increase the short-term probability of supporting a partner, and being supported did not increase the short-term probability of grooming a partner. The proximate mechanisms underlying the exchange of services were discussed in relation to the time frame of the behavioral choices made by the monkeys. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
|
|
White, A. M., Swaisgood, R. R., & Czekala, N. (2007). Ranging patterns in white rhinoceros, Ceratotherium simum simum: implications for mating strategies. Appl. Anim. Behav. Sci., 74(2), 349–356.
Abstract: How animals use space has important consequences for feeding ecology, social organization, mating strategies and conservation management. In white rhinoceros, female home ranges are much larger than male territories, suggesting that movement patterns are influenced by factors other than resource distribution. In this study we placed radiotransmitters on 15 female white rhinoceros, recording 1758 locations and collecting behavioural data during 1671 observation sessions, making this the largest data set of its kind in this species. We investigated how habitat variables and male territories influenced female movement and reproductive behaviour. Female home ranges were approximately 20 km2 and core areas were 5 km2, with male territories roughly the same size as female core areas. Female range size did not vary with season, but the pattern of space use did vary. Females used grassland habitat preferentially, utilizing these areas significantly more than expected based on availability. Findings relevant to the mating strategy include: (1) the amount of grassland in a male's territory predicted female use of the territory; (2) the time that a female spent in a male's territory was a significant predictor of reproductive activity with the male, indicating that females probably mate with the most familiar male; and (3) the temporal pattern of female space use suggests that females did not increase mate sampling behaviour nor did they become more choosy about which males they visited when reproductively active. These findings suggest that males may maximize reproductive success by defending areas containing more grassland habitat.
|