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Fischer, J., Hammerschmidt, K., Cheney, D. L., & Seyfarth, R. M. (2002). Acoustic features of male baboon loud calls: influences of context, age, and individuality. J Acoust Soc Am, 111(3), 1465–1474.
Abstract: The acoustic structure of loud calls (“wahoos”) recorded from free-ranging male baboons (Papio cynocephalus ursinus) in the Moremi Game Reserve, Botswana, was examined for differences between and within contexts, using calls given in response to predators (alarm wahoos), during male contests (contest wahoos), and when a male had become separated from the group (contact wahoos). Calls were recorded from adolescent, subadult, and adult males. In addition, male alarm calls were compared with those recorded from females. Despite their superficial acoustic similarity, the analysis revealed a number of significant differences between alarm, contest, and contact wahoos. Contest wahoos are given at a much higher rate, exhibit lower frequency characteristics, have a longer “hoo” duration, and a relatively louder “hoo” portion than alarm wahoos. Contact wahoos are acoustically similar to contest wahoos, but are given at a much lower rate. Both alarm and contest wahoos also exhibit significant differences among individuals. Some of the acoustic features that vary in relation to age and sex presumably reflect differences in body size, whereas others are possibly related to male stamina and endurance. The finding that calls serving markedly different functions constitute variants of the same general call type suggests that the vocal production in nonhuman primates is evolutionarily constrained.
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Seyfarth, R. M., & Cheney, D. L. (2002). What are big brains for? Proc. Natl. Acad. Sci. U.S.A., 99(7), 4141–4142.
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Rivera, E., Benjamin, S., Nielsen, B., Shelle, J., & Zanella, A. J. (2002). Behavioral and physiological responses of horses to initial training: the comparison between pastured versus stalled horses. Appl. Anim. Behav. Sci., 78(2-4), 235–252.
Abstract: Horses kept in stalls are deprived of opportunities for social interactions, and the performance of natural behaviors is limited. Inadequate environmental conditions may compromise behavioral development. Initial training is a complex process and it is likely that the responses of horses may be affected by housing conditions. Sixteen 2-year-old Arabian horses were kept on pasture (P) (n=8) or in individual stalls (S) (n=8). Twelve horses (six P and six S) were subjected to a standardized training procedure, carried out by two trainers in a round pen, and 4 horses (two P and two S) were introduced to the round pen but were not trained (C; control). On sample collection day 0, 7, 21 and 28, behavior observations were carried out, blood samples were drawn and heart rates were monitored. Total training time for the stalled horses was significantly higher than total time for the pastured horses (S: 26.4+/-1.5 min; P: 19.7+/-1.1; P=0.032). The stalled group required more time to habituate to the activities occurring from the start of training to mounting (S: 11.4+/-0.96; P: 7.3+/-0.75 min; P=0.007). Frequency of unwanted behavior was higher in the stalled horses (S: 8.0+/-2.0; P: 2.2+/-1.0; P=0.020). Pastured horses tended to have higher basal heart rates on day 0 (S: 74.7+/-4.8; P: 81.8+/-5.3 bpm; P=0.0771). While the physiological data failed to identify differences between housing groups, the behavioral data suggest that pasture-kept horses adapt more easily to training than stalled horses.
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Byrne, R. W. (2002). Imitation of novel complex actions: What does the evidence from animals mean? In C. T. Snowdon, T. J. Roper, & J. S. Rosenblatt (Eds.), Advances in the Study of Behavior (Vol. 31, pp. 77–105). San Diego: Academic Press.
Abstract: Summary Underlying the various behaviors that are classified as imitation, there may be several distinct mechanisms, differing in adaptive function, cognitive basis, and computational power. Experiments reporting “true motor imitation” in animals do not as yet give evidence of production learning by imitation; instead, contextual imitation can explain their data, and this can be explained by a simple mechanism (response facilitation) which matches known neural findings. When imitation serves a function in social mimicry, which applies to a wide range of phenomena from neonatal imitation in humans and great apes to pair-bonding in some bird species, the fidelity of the behavioral match is crucial. Learning of novel behavior can potentially be achieved by matching the outcome of a model's action, and it is argued that vocal imitation by birds is a clear example of this method (which is sometimes called emulation). Alternatively, the behavior itself may be perceived in terms of actions that the observer can perform, and thus it may be copied. If the imitation is linear and stringlike (action level), following the surface form rather than the underlying plan, then its utility for learning new instrumental methods is limited. However, the underlying plan of hierarchically organized behavior is visible in output behavior, in subtle but detectable ways, and imitation could instead be based on this organization (program level), extracted automatically by string parsing. Currently, the most likely candidates for such capacities are all great apes. It is argued that this ability to perceive the underlying plan of action, in addition to allowing highly flexible imitation of novel instrumental methods, may have resulted in the competence to understand the intentions (theory of mind) of others.
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Dyer, F. C. (2002). Animal behaviour: when it pays to waggle (Vol. 419).
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Jansen, T., Forster, P., Levine, M. A., Oelke, H., Hurles, M., Renfrew, C., et al. (2002). Mitochondrial DNA and the origins of the domestic horse. Proc. Natl. Acad. Sci. U.S.A., 99(16), 10905–10910.
Abstract: The place and date of the domestication of the horse has long been a matter for debate among archaeologists. To determine whether horses were domesticated from one or several ancestral horse populations, we sequenced the mitochondrial D-loop for 318 horses from 25 oriental and European breeds, including American mustangs. Adding these sequences to previously published data, the total comes to 652, the largest currently available database. From these sequences, a phylogenetic network was constructed that showed that most of the 93 different mitochondrial (mt)DNA types grouped into 17 distinct phylogenetic clusters. Several of the clusters correspond to breeds and/or geographic areas, notably cluster A2, which is specific to Przewalski's horses, cluster C1, which is distinctive for northern European ponies, and cluster D1, which is well represented in Iberian and northwest African breeds. A consideration of the horse mtDNA mutation rate together with the archaeological timeframe for domestication requires at least 77 successfully breeding mares recruited from the wild. The extensive genetic diversity of these 77 ancestral mares leads us to conclude that several distinct horse populations were involved in the domestication of the horse.
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Christensen, J. W., Zharkikh, T., Ladewig, J., & Yasinetskaya, N. (2002). Social behaviour in stallion groups (Equus przewalskii and Equus caballus) kept under natural and domestic conditions. Appl. Anim. Behav. Sci., 76(1), 11–20.
Abstract: The aim of this study was to investigate social behaviour in differently reared stallions in their respective environments; one group of stallions was reared under typical domestic conditions whereas the other group was reared and lives under natural conditions. The domestic group consisted of 19, 2-year-old stallions (Equus caballus), which were all weaned at 4 months of age and experienced either individual or group housing facilities before being pastured with the other similarly aged stallions. The natural living and mixed age group of Przewalski stallions (E. przewalskii) consisted of 13 stallions, most of which were juveniles (n=11, <=4 years; n=2, >9 years). The domestic group was studied in a 4-ha enclosure at the Danish Institute of Agricultural Sciences and the Przewalski group under free-ranging conditions in a 75-ha enclosure in the Askania Nova Biosphere Reserve, Ukraine. Behavioural data was collected during 168 h of direct observation. The occurrence of 14 types of social interactions was recorded and group spacing behaviour was studied using nearest neighbour recordings. In spite of very different environments, reflecting domestic and natural rearing conditions, many similarities in behaviour was found. Play and play fight behaviour was very similar in the two stallion groups. Quantitative differences were found in social grooming since Przewalski stallions groomed more frequently (P=0.004), and in investigative behaviours, since domestic stallions showed more nasal (P=0.005) and body sniffing (P<0.001), whereas Przewalski stallions directed more sniffing towards the genital region (P<0.001). These differences may, however, be attributed to environmental factors and in the period of time the stallions were together prior to the study period. Quantitative differences appeared in some agonistic behaviours (kick threat, P<0.001; and kick, P<0.001), but data do not support earlier findings of Przewalski horses being significantly more aggressive than domestic horses. In general, Przewalski stallions engaged in more social interactions, and they showed less group spacing, i.e. maintained a significantly shorter distance between neighbours (P<0.001). The study indicates that also domestic horses, which have been reared under typical domestic conditions and allowed a period on pasture, show social behaviour, which is very similar to that shown by their non-domestic relatives.
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Hemelrijk, C. K. (2002). Despotic societies, sexual attraction and the emergence of male 'tolerance': an agent-based model. Behaviour, 139(6), 729–747.
Abstract: During the period when females are sexually attractive – but only then – males of certain species of primates, such as chimpanzees, allow females access to resources. Because males are usually dominant over females, such male 'tolerance' is explained as a special, reproductive strategy to gain access to females. In this paper a simpler hypothesis is proposed on the basis of an individual-based model (called DomWorld): male 'tolerance' towards females arises in 'despotic' artificial societies as a kind of 'respectful timidity', because sexual attraction automatically increases female dominance over males as a side-effect. The model consists in a homogeneous, virtual world with agents that group and perform dominance-interactions in which the effects of victory and defeat are self-reinforcing. The artificial sexes differ in that VirtualMales have a higher intensity of aggression, they start with a greater capacity to win conflicts than VirtualFemales and they are especially attracted to the opposite sex during certain periods, whereas VirtualFemales are not. I shall explain how the introduction into DomWorld of the attraction of VirtualMales by VirtualFemales leads to female dominance, why it does so only in despotic, but not in egalitarian societies, and how it leads to other phenomena that are relevant to the study of primate behaviour.
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Huebener, E. (2002). Schmeichelnder Sitz, atmender Schenkel, flüsternder Zügel.
Abstract: HÜBENER, EBERHARD, Schmeichelnder Sitz, atmender Schenkel,
flüsternder Zügel
Vom feinfühligen, partnerschaftlichen Umgang mit dem Pferd und über Nöte
der bundesdeutschen Reiterei. Mit einem Geleitwort von Dr. Reiner Klimke
2. ergänzte Aufl. Hildesheim 2002. 223 S. mit 63 Abb., davon 3 farbig. Gebunden. Reihe:
(NOVA HIPPOLOGICA.) ISBN: 3-487-08408-2
Dieses Buch beantwortet eine Reihe zentraler Fragen zur Reitlehre und zum
Umgang mit dem Pferd gründlich und leicht verständlich. Es ist daher hilfreich
für alle, die sich am und auf dem Pferd gern helfen lassen. Ob sie nun nur zum
Vergnügen oder mit turniersportlichen Ambitionen reiten. Ob sie lernen oder
lehren.
Der vorliegenden zweiten Auflage ist eine neue Arbeit des Autors beigebunden:
Nachdem eine Video-Analyse seinen “selbsttätigen Schenkel” bestätigt hat, wird
jetzt endlich auch das “Sitz-Rätsel” definitiv gelöst.
Die Video-Technik hat ermöglicht, das Zusammenspiel von Gangart, Bewegungen
von Pferderumpf und -rücken, Sitz des Reiters und Hilfengebung zum Nutzen
des Reiter-Rückgrats, der keineswegs beliebig belastbaren Wirbelsäule des
Pferdes und kultivierten, feinfühligen Reitens zu entschlüsseln.
Reitunterricht kann anders aussehen. Irrwege sind vermeidbar geworden.
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Huebener, E. (2002). Coaxing seat, breathing leg, whispering reins.
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