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Tennie, C., Call, J., & Tomasello, M. (2012). Untrained chimpanzees (Pan troglodytes schweinfurthii) fail to imitate novel actions. PLoS One, 7.
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Broekhuis, F., Madsen, E. K., Keiwua, K., & Macdonald, D. W. (2019). Using GPS collars to investigate the frequency and behavioural outcomes of intraspecific interactions among carnivores: A case study of male cheetahs in the Maasai Mara, Kenya. Plos One, 14(4), e0213910.
Abstract: Intraspecific interactions between individuals or groups of individuals of the same species are an important component of population dynamics. Interactions can be static, such as spatial overlap, or dynamic based on the interactions of movements, and can be mediated through communication, such as the deployment of scent marks. Interactions and their behavioural outcomes can be difficult to determine, especially for species that live at low densities. With the use of GPS collars we quantify both static and dynamic interactions between male cheetahs (Acinonyx jubatus) and the behavioural outcomes. The 99% home-ranges of males overlapped significantly while there was little overlap of the 50% home-ranges. Despite this overlap, male cheetahs rarely came into close proximity of one another, possibly because presence was communicated through frequent visits to marking posts. The minimum distance between individuals in a dyad ranged from 89m to 196m but the average proximity between individuals ranged from 17,145 ± 6,865m to 26,367 ± 11,288m. Possible interactions took place more frequently at night than by day and occurred mostly in the 50% home-range of one individual of a dyad or where cores of both individuals overlapped. After a possible encounter male cheetahs stayed in close proximity to each other for up to 6 hours, which could be the result of a territory defence strategy or the presence of a receptive female. We believe that one of the encounters between a singleton and a 5-male coalition resulted in the death of the singleton. Our results give new insights into cheetah interactions, which could help our understanding of ecological processes such as disease transmission.
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Karenina, K., Giljov, A., Baranov, V., Osipova, L., Krasnova, V., & Malashichev, Y. (2010). Visual Laterality of Calf–Mother Interactions in Wild Whales. PLoS ONE, 5(11), e13787.
Abstract: Background
Behavioral laterality is known for a variety of vertebrate and invertebrate animals. Laterality in social interactions has been described for a wide range of species including humans. Although evidence and theoretical predictions indicate that in social species the degree of population level laterality is greater than in solitary ones, the origin of these unilateral biases is not fully understood. It is especially poorly studied in the wild animals. Little is known about the role, which laterality in social interactions plays in natural populations. A number of brain characteristics make cetaceans most suitable for investigation of lateralization in social contacts. Methodology/Principal Findings Observations were made on wild beluga whales (Delphinapterus leucas) in the greatest breeding aggregation in the White Sea. Here we show that young calves (in 29 individually identified and in over a hundred of individually not recognized mother-calf pairs) swim and rest significantly longer on a mother's right side. Further observations along with the data from other cetaceans indicate that found laterality is a result of the calves' preference to observe their mothers with the left eye, i.e., to analyze the information on a socially significant object in the right brain hemisphere. Conclusions/Significance Data from our and previous work on cetacean laterality suggest that basic brain lateralizations are expressed in the same way in cetaceans and other vertebrates. While the information on social partners and novel objects is analyzed in the right brain hemisphere, the control of feeding behavior is performed by the left brain hemisphere. Continuous unilateral visual contacts of calves to mothers with the left eye may influence social development of the young by activation of the contralateral (right) brain hemisphere, indicating a possible mechanism on how behavioral lateralization may influence species life and welfare. This hypothesis is supported by evidence from other vertebrates. |
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Zhang, Y., Cao, Q. S., Rubenstein, D. I., Zang, S., Songer, M., Leimgruber, P., et al. (2015). Water Use Patterns of Sympatric Przewalski's Horse and Khulan: Interspecific Comparison Reveals Niche Differences. Plos One, 10(7), e0132094.
Abstract: Acquiring water is essential for all animals, but doing so is most challenging for desert-living animals. Recently Przewalski's horse has been reintroduced to the desert area in China where the last wild surviving member of the species was seen before it vanished from China in the1960s. Its reintroduction placed it within the range of a close evolutionary relative, the con-generic Khulan. Determining whether or not these two species experience competition and whether or not such competition was responsible for the extinction of Przewalski's horses in the wild over 50 years ago, requires identifying the fundamental and realized niches of both species. We remotely monitored the presence of both species at a variety of water points during the dry season in Kalamaili Nature Reserve, Xinjiang, China. Przewalski's horses drank twice per day mostly during daylight hours at low salinity water sources while Khulans drank mostly at night usually at high salinity water points or those far from human residences. Spatial and temporal differences in water use enables coexistence, but suggest that Przewalski's horses also restrict the actions of Khulan. Such differences in both the fundamental and realized niches were associated with differences in physiological tolerances for saline water and human activity as well as differences in aggression and dominance.
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Roubová, V., Konecná, M., Smilauer, P., & Wallner, B. (2015). Whom to Groom and for What? Patterns of Grooming in Female Barbary Macaques (Macaca sylvanus). Plos One, 10(2), e0117298.
Abstract: Grooming is one of the most conspicuous social interactions among nonhuman primates. The selection of grooming partners can provide important clues about factors relevant for the distribution of grooming within a social group. We analyzed grooming behavior among 17 semi-free ranging female Barbary macaques (Macaca sylvanus). We tested whether grooming is related to kinship, rank and friendship. Furthermore, we tested whether grooming is reciprocated or exchanged for rank related benefits (i.e. lower aggression and increased tolerance whilst feeding). We found that in general grooming was reciprocally exchanged, directed up the hierarchy and at the same time affected by friendship and kinship. Grooming was more frequent among individuals with higher friendship values as well as amongst related individuals. We also divided our data set on the basis of rank difference and tested if different power asymmetries between individuals affected the tendency to exchange grooming for rank related benefits and grooming reciprocation. In support of our initial hypothesis our results show that the reciprocation of grooming was a significant predictor of grooming interactions between individuals of similar rank, but not between those individuals more distantly separated in the social hierarchy. However, we did not find any evidence for grooming being exchanged for rank related benefits in either data set. Our results, together with previously published studies, illustrate the behavioral flexibility of macaques. It is clear that multiple studies of the same species are necessary to gather the data required for the solid comparative studies needed to shed light on patterns of grooming behavior in primates.
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Krueger, K., Gruentjens, T., & Hempel, E. (2023). Wolf contact in horses at permanent pasture in Germany. Plos One, 18(8), e0289767.
Abstract: Wolves returned to Germany in 2000, leading to fear in German horse owners that their horses could be in danger of wolf attacks or panic-like escapes from pastures when sighting wolves. However, reports from southern European countries indicate that wolf predation on horses diminishes with increasing presence of wildlife. Therefore, we conducted a long-term, filed observation between January 2015 and July 2022 on 13 non breeding riding horses, mares and geldings, kept permanently on two pastures within the range of wildlife and a stable wolf pack with annual offspring. Wildlife cameras at the fences of the pastures made 984 times recordings of wolves and 3151 times recordings of wildlife in and around the pastures. Between 1 January 2022 and 23 March 2022 we observed two stable horse groups. Pasture 1 was grazed by five horses of mixed breed, four mares and one gelding, with the median age of 8 years (min. = 6y, max. = 29y). Pasture 2 was grazed by eight heavy warmbloods and draught horses, three mares and five geldings, with the median age of 16 years (min. = 13y, max. = 22y). During this period no wolf was recorded at pasture 2, but wild boar several times, whereas at pasture 1, wolves were recorded 89 times, and for the wildlife mostly hare. Wolves may have avoided pasture 2 because of the presence of wild boar or because the large group of older, heavy breed horses may have formed a stable, protective group. The latter needs to be confirmed in a follow-up field observation, which records anti-predator behavior and welfare indicators in horses. In conclusion, wolves did not attack the mature horses on pastures with plenty of wildlife and the horses did not respond to the presence of wolves with visible signs of reduced welfare or panic. This indicates that wolves may prefer to prey on easily accessible wildlife around and at horse pastures and that Central European horses become accustom to the presence of non-hunting wolves.
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Range, F., & Virányi, Z. (2014). Wolves are better imitators of conspecifics than dogs. PLoS One, 9.
Abstract: Domestication is thought to have influenced the cognitive abilities of dogs underlying their communication with humans, but little is known about its effect on their interactions with conspecifics. Since domestication hypotheses offer limited predictions in regard to wolf-wolf compared to dog-dog interactions, we extend the cooperative breeding hypothesis suggesting that the dependency of wolves on close cooperation with conspecifics, including breeding but also territory defense and hunting, has created selection pressures on motivational and cognitive processes enhancing their propensity to pay close attention to conspecifics’ actions. During domestication, dogs’ dependency on conspecifics has been relaxed, leading to reduced motivational and cognitive abilities to interact with conspecifics. Here we show that 6-month-old wolves outperform same aged dogs in a two-action-imitation task following a conspecific demonstration. While the wolves readily opened the apparatus after a demonstration, the dogs failed to solve the problem. This difference could not be explained by differential motivation, better physical insight of wolves, differential developmental pathways of wolves and dogs or a higher dependency of dogs from humans. Our results are best explained by the hypothesis that higher cooperativeness may come together with a higher propensity to pay close attention to detailed actions of others and offer an alternative perspective to domestication by emphasizing the cooperativeness of wolves as a potential source of dog-human cooperation.
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