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Lansade, L., Colson, V., Parias, C., Trösch, M., Reigner, F., & Calandreau, L. (2020). Female horses spontaneously identify a photograph of their keeper, last seen six months previously. Scientific Reports, 10(1), 6302.
Abstract: Horses are capable of identifying individual conspecifics based on olfactory, auditory or visual cues. However, this raises the questions of their ability to recognize human beings and on the basis of what cues. This study investigated whether horses could differentiate between a familiar and unfamiliar human from photographs of faces. Eleven horses were trained on a discrimination task using a computer-controlled screen, on which two photographs were presented simultaneously (32 trials/session): touching one was rewarded (S+) and the other not (S-). In the training phase, the S+ faces were of four unfamiliar people which gradually became familiar over the trials. The S- faces were novel for each trial. After the training phase, the faces of the horses' keepers were presented opposite novel faces to test whether the horses could identify the former spontaneously. A reward was given whichever face was touched to avoid any possible learning effect. Horses touched the faces of keepers significantly more than chance, whether it was their current keeper or one they had not seen for six months (t = 3.65; p < 0.004 and t = 6.24; p < 0.0001). Overall, these results show that horses have advanced human face-recognition abilities and a long-term memory of those human faces.
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d'Ingeo, S., Quaranta, A., Siniscalchi, M., Stomp, M., Coste, C., Bagnard, C., et al. (2019). Horses associate individual human voices with the valence of past interactions: a behavioural and electrophysiological study. Scientific Reports, 9(1), 11568.
Abstract: Brain lateralization is a phenomenon widely reported in the animal kingdom and sensory laterality has been shown to be an indicator of the appraisal of the stimulus valence by an individual. This can prove a useful tool to investigate how animals perceive intra- or hetero-specific signals. The human-animal relationship provides an interesting framework for testing the impact of the valence of interactions on emotional memories. In the present study, we tested whether horses could associate individual human voices with past positive or negative experiences. Both behavioural and electroencephalographic measures allowed examining laterality patterns in addition to the behavioural reactions. The results show that horses reacted to voices associated with past positive experiences with increased attention/arousal (gamma oscillations in the right hemisphere) and indicators of a positive emotional state (left hemisphere activation and ears held forward), and to those associated with past negative experiences with negative affective states (right hemisphere activation and ears held backwards). The responses were further influenced by the animals' management conditions (e.g. box or pasture). Overall, these results, associating brain and behaviour analysis, clearly demonstrate that horses' representation of human voices is modulated by the valence of prior horse-human interactions.
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Camerlink, I., Menneson, S., Turner, S. P., Farish, M., & Arnott, G. (2018). Lateralization influences contest behaviour in domestic pigs. Scientific Reports, 8(1), 12116.
Abstract: Cerebral lateralization, i.e. hemispheric asymmetries in structure and function, relates in many species to a preference to attack from their left. Lateralization increases cognitive capacity, enabling the simultaneous processing of multiple sources of information. Therefore, lateralization may constitute a component of fighting ability (Resource Holding Potential), and/or influence the efficiency of information-gathering during a contest. We hypothesized that lateralization will affect contest outcome and duration, with an advantage for more strongly lateralized individuals. In 52 dyadic contests between weight-matched pigs (Sus scrofa; n = 104; 10 wk age), the direction of orientation towards the opponent was scan sampled every 10 s. Laterality indexes (LI) were calculated for the direction and strength of lateralization. Up to 12.5% of the individuals showed significant lateralization towards either the right or left but lateralization was absent at the population level. In line with our hypothesis, animals showing strong lateralization (irrespective of direction) had a shorter contest duration than animals showing weak lateralization. Winners did not differ from losers in their strength or direction of lateralization. Overall the results suggest that cerebral lateralization may aid in conflict resolution, but does not directly contribute to fighting ability, and will be of value in the study of animal contests.
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Jarausch, A., Harms, V., Kluth, G., Reinhardt, I., & Nowak, C. (2021). How the west was won: genetic reconstruction of rapid wolf recolonization into Germany's anthropogenic landscapes. Heredity, .
Abstract: Following massive persecution and eradication, strict legal protection facilitated a successful reestablishment of wolf packs in Germany, which has been ongoing since 2000. Here, we describe this recolonization process by mitochondrial DNA control-region sequencing, microsatellite genotyping and sex identification based on 1341 mostly non-invasively collected samples. We reconstructed the genealogy of German wolf packs between 2005 and 2015 to provide information on trends in genetic diversity, dispersal patterns and pack dynamics during the early expansion process. Our results indicate signs of a founder effect at the start of the recolonization. Genetic diversity in German wolves is moderate compared to other European wolf populations. Although dispersal among packs is male-biased in the sense that females are more philopatric, dispersal distances are similar between males and females once only dispersers are accounted for. Breeding with close relatives is regular and none of the six male wolves originating from the Italian/Alpine population reproduced. However, moderate genetic diversity and inbreeding levels of the recolonizing population are preserved by high sociality, dispersal among packs and several immigration events. Our results demonstrate an ongoing, rapid and natural wolf population expansion in an intensively used cultural landscape in Central Europe.
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Heyes, C. (2012). What's social about social learning? J Comp Psychol, 120.
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Whiten, A. (1998). Imitation of the sequential structure of actions by chimpanzees. J Comp Psychol, 11.
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Kleiven, J., Bjerke, T., & Kaltenborn, B. P. (2004). Factors influencing the social acceptability of large carnivore behaviours. Biodivers Conserv, 13.
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Murphy, M. A., Waits, L. P., Kendall, K. C., Wasser, S. K., Higbee, J. A., & Bogden, R. (2002). An evaluation of long-term preservation methods for brown bear (Ursus arctos) faecal DNA samples. Conservat. Genet., 3(4), 435–440.
Abstract: Relatively few large-scale faecal DNA studieshave been initiated due to difficulties inamplifying low quality and quantity DNAtemplate. To improve brown bear faecal DNA PCRamplification success rates and to determinepost collection sample longevity, fivepreservation methods were evaluated: 90%ethanol, DETs buffer, silica-dried, oven-driedstored at room temperature, and oven-driedstored at -20 °C. Preservationeffectiveness was evaluated for 50 faecalsamples by PCR amplification of a mitochondrialDNA (mtDNA) locus (~146 bp) and a nuclear DNA(nDNA) locus (~200 bp) at time points of oneweek, one month, three months and six months. Preservation method and storage timesignificantly impacted mtDNA and nDNAamplification success rates. For mtDNA, allpreservation methods had >= 75% success atone week, but storage time had a significantimpact on the effectiveness of the silicapreservation method. Ethanol preserved sampleshad the highest success rates for both mtDNA(86.5%) and nDNA (84%). Nuclear DNAamplification success rates ranged from 26-88%, and storage time had a significant impacton all methods but ethanol. Preservationmethod and storage time should be importantconsiderations for researchers planningprojects utilizing faecal DNA. We recommendpreservation of faecal samples in 90% ethanolwhen feasible, although when collecting inremote field conditions or for both DNA andhormone assays a dry collection method may beadvantageous.
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Walpole, M. J., & Leader-Williams, N. (2002). Tourism and flagship species in conservation. Biodivers Conserv, 11.
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Silanikove, N. (2000). The physiological basis of adaptation in goats to harsh environments. Small Rum Res, 35.
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