The Experts below are selected from a list of 2055 Experts worldwide ranked by ideXlab platform
Karen Mccomb - One of the best experts on this subject based on the ideXlab platform.
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functionally relevant responses to human facial expressions of emotion in the Domestic Horse equus caballus
Biology Letters, 2016Co-Authors: Amy Victoria Smith, Leanne Proops, Kate Grounds, Jennifer Wathan, Karen MccombAbstract:Whether non-human animals can recognize human signals, including emotions, has both scientific and applied importance, and is particularly relevant for Domesticated species. This study presents the first evidence of Horses' abilities to spontaneously discriminate between positive (happy) and negative (angry) human facial expressions in photographs. Our results showed that the angry faces induced responses indicative of a functional understanding of the stimuli: Horses displayed a left-gaze bias (a lateralization generally associated with stimuli perceived as negative) and a quicker increase in heart rate (HR) towards these photographs. Such lateralized responses towards human emotion have previously only been documented in dogs, and effects of facial expressions on HR have not been shown in any heterospecific studies. Alongside the insights that these findings provide into interspecific communication, they raise interesting questions about the generality and adaptiveness of emotional expression and perception across species.
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Cross-modal individual recognition in Domestic Horses (Equus caballus) extends to familiar humans
Proceedings of The Royal Society B: Biological Sciences, 2012Co-Authors: Leanne Proops, Karen MccombAbstract:It has recently been shown that some non-human animals can cross-modally recognize members of their own taxon. What is unclear is just how plastic this recognition system can be. In this study, we investigate whether an animal, the Domestic Horse, is capable of spontaneous cross-modal recognition of individuals from a morphologically very different species. We also provide the first insights into how cross-modal identity information is processed by examining whether there are hemispheric biases in this important social skill. In our preferential looking paradigm, subjects were presented with two people and playbacks of their voices to determine whether they were able to match the voice with the person. When presented with familiar handlers subjects could match the specific familiar person with the correct familiar voice. Horses were significantly better at performing the matching task when the congruent person was standing on their right, indicating marked hemispheric specialization (left hemisphere bias) in this ability. These results are the first to demonstrate that cross-modal recognition in animals can extend to individuals from phylogenetically very distant species. They also indicate that processes governed by the left hemisphere are central to the cross-modal matching of visual and auditory information from familiar individuals in a naturalistic setting.
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Cross-modal individual recognition in Domestic Horses (Equus caballus).
Proceedings of the National Academy of Sciences of the United States of America, 2008Co-Authors: Leanne Proops, Karen Mccomb, David RebyAbstract:Individual recognition is considered a complex process and, although it is believed to be widespread across animal taxa, the cognitive mechanisms underlying this ability are poorly understood. An essential feature of individual recognition in humans is that it is cross-modal, allowing the matching of current sensory cues to identity with stored information about that specific individual from other modalities. Here, we use a cross-modal expectancy violation paradigm to provide a clear and systematic demonstration of cross-modal individual recognition in a nonhuman animal: the Domestic Horse. Subjects watched a herd member being led past them before the individual went of view, and a call from that or a different associate was played from a loudspeaker positioned close to the point of disappearance. When Horses were shown one associate and then the call of a different associate was played, they responded more quickly and looked significantly longer in the direction of the call than when the call matched the herd member just seen, an indication that the incongruent combination violated their expectations. Thus, Horses appear to possess a cross-modal representation of known individuals containing unique auditory and visual/olfactory information. Our paradigm could provide a powerful way to study individual recognition across a wide range of species.
Jan Pluhacek - One of the best experts on this subject based on the ideXlab platform.
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male free environment prevents pregnancy disruption in Domestic Horse mares mated away of home
Applied Animal Behaviour Science, 2017Co-Authors: Luděk Bartos, Jitka Bartosova, Jan PluhacekAbstract:Abstract In a previous study (Bartos et al., 2011) we have reported on the effects of the male social environment on the maintenance or disruption of pregnancy in Domestic mares mated away from home. In this follow-up study we compare the effects of returning to a home environment including a male (or males) to which the returning mare had, or was denied, access or did not have access, with that of returning to a home environment containing only other females. As in the previous study, we used data collected from private Horse owners in the Czech Republic. The probability of disruption of pregnancy was lowest when the mare was sharing an enclosure only with other mares. Incidence of pregnancy failure was highest when the mare was in one enclosure, while the male or males stayed in an adjacent enclosure and intermediate where females returned to a home enclosure and shared it with the home male(s). In addition, the probability of pregnancy disruption decreased with increasing number of foals delivered in the mare’s previous reproductive history.
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pregnancy disruption in artificially inseminated Domestic Horse mares as a counterstrategy against potential infanticide
Journal of Animal Science, 2015Co-Authors: Luděk Bartos, Jitka Bartosova, Jan PluhacekAbstract:In a previous study, we suggested that the common practice of transporting a mare for mating and then bringing her back to an environment that also contains males that did not sire the fetus may be a major cause of high percentages of pregnancy disruption in Domestic Horses. In this study, we tested whether disruption of pregnancies induced by AI occurs as frequently as after mating with a strange stallion away from home and is affected by the same factors in the home social environment. Based on 77 records, the probability of pregnancy disruption after AI depended on the social environment in which the mare was maintained after mating and the number of foals the mare had delivered in the past. Also after AI, as with natural matings away from home, the probability of pregnancy disruption was higher when the mare had no male company in her enclosure but stallions or geldings were present in an adjacent enclosure than when the mare was sharing the enclosure with geldings (generalized linear mixed model = 8.68, = 0.007, odds ratio = 8.17). These data support the prediction that the mare perceives conception after AI equally to natural mating with a strange stallion. The results suggested pregnancy disruption may be stimulated by the social circumstances of the home environment in mares artificially inseminated as in mares mated naturally away from home. The practical implications of this result is that after AI, to reduce risk of pregnancy disruption and improve welfare, Horse breeders should place the pregnant mare into an environment with no stallion or stallions/gelding or geldings or to an enclosure together with the male or males.
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concurrent lactation and pregnancy pregnant Domestic Horse mares do not increase mother offspring conflict during intensive lactation
PLOS ONE, 2011Co-Authors: Jitka Bartosova, Luděk Bartos, Jana Dubcová, Martina Komarkova, Jan PluhacekAbstract:Lactation is the most energy demanding part of parental care in mammals, so parent-offspring conflict arises over milk provided by the mother. In some species females commonly become pregnant shortly after parturition of previous young. This further intensifies mother-offspring conflict due to concurrent pregnancy and lactation. In equids it has been well established that pregnant females wean their foals earlier than non-pregnant ones. Intensified mother-offspring conflict was presumed to associate with pregnancy also during the period of intensive lactation, i.e., before the weaning process starts. We investigated the effect of pregnancy on suckling behaviour characteristics as indicators of mother-offspring conflict in Domestic Horses. Contrary to expectation, here we provide evidence of a decreased mother-offspring conflict related to pregnancy in lactating females during first two trimesters of pregnancy. Pregnant mares provided longer suckling bouts and did not reject or terminate suckling of their foals more often than non-pregnant mares. Our results suggest that pregnant mares cope with parallel investment into a nursed foal and a foetus through enhancing nursing behaviour in early stages of pregnancy before the initially low requirements of the foetus increase. They compensate their suckling foal with the perspective of its early weaning due to ongoing pregnancy.
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promiscuous behaviour disrupts pregnancy block in Domestic Horse mares
Behavioral Ecology and Sociobiology, 2011Co-Authors: Luděk Bartos, Jitka Bartosova, Jan Pluhacek, Jana SindelařovaAbstract:Based on questionnaires from Horse breeders, we found that bringing a pregnant mare which had been mated away from home into a vicinity of a familiar male who was not the father of her foetus increased probability of pregnancy disruption. These mares aborted in 31% of cases, while none of those mated within the home stable aborted. Repeated sexual activity either by a stallion or dominant gelding from the normal home group was observed shortly after the mare came from away-mating. Pregnant mares isolated from home males by a fence were even seen soliciting them over the fence. We speculate that, once returned to the home “herd”, and introduced to familiar males, mares were more likely to terminate their pregnancy to save energy and avoid likely future infanticidal loss of their progeny by dominant male(s) of the home social group. This is a newly discovered phenomenon where a mare manipulates the male’s paternity assessment by promiscuous mating. It may explain a common increased incidence of foetal loss in Domestic Horses occurring in nearly 40% of pregnancies. We conclude that the common practice of transporting the mare for mating and then bringing her back to an environment with males, stallions or geldings, which did not sire the foetus, is the main cause of high percentages of pregnancy disruption in Domestic Horses.
Leanne Proops - One of the best experts on this subject based on the ideXlab platform.
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functionally relevant responses to human facial expressions of emotion in the Domestic Horse equus caballus
Biology Letters, 2016Co-Authors: Amy Victoria Smith, Leanne Proops, Kate Grounds, Jennifer Wathan, Karen MccombAbstract:Whether non-human animals can recognize human signals, including emotions, has both scientific and applied importance, and is particularly relevant for Domesticated species. This study presents the first evidence of Horses' abilities to spontaneously discriminate between positive (happy) and negative (angry) human facial expressions in photographs. Our results showed that the angry faces induced responses indicative of a functional understanding of the stimuli: Horses displayed a left-gaze bias (a lateralization generally associated with stimuli perceived as negative) and a quicker increase in heart rate (HR) towards these photographs. Such lateralized responses towards human emotion have previously only been documented in dogs, and effects of facial expressions on HR have not been shown in any heterospecific studies. Alongside the insights that these findings provide into interspecific communication, they raise interesting questions about the generality and adaptiveness of emotional expression and perception across species.
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Social cognition in Domestic Horses (Equus caballus)
2012Co-Authors: Leanne ProopsAbstract:The social intelligence hypothesis states that the main selection pressures driving increases in brain-to-body ratio are social rather than ecological. The Domestic Horse is an ideal animal to study within this framework because Horses possess rich social lives but inhabit simple ecological environments. Here I assess the abilities of Horses within two broad areas of social cognition; the classification of, and the use of information obtained from, social partners. In Section One I demonstrate that Horses are capable of cross-modal individual recognition of conspecifics, an ability not previously demonstrated conclusively outside of humans. This ability extends to identifying familiar human companions suggesting that recognition systems are highly plastic in the individuals they can encode. These results also provide the first insights into the brain mechanisms involved in this process by revealing a clear left hemisphere bias in discriminatory ability. In Section Two I investigate the extent to which Horses are capable of reading human attentional and communicative cues. It has been suggested that this skill was selected for through the process of Domestication, however there have been no systematic studies of Domestic animals other than the Domestic dog. I found that Horses were indeed highly skilled at determining if people were paying attention to them. In contrast they tended to only use basic stimulus enhancement cues to choose a rewarded bucket. A further study of young Horses indicated that the ability to detect human attention requires significant experience to develop fully whereas the ability to use stimulus enhancement cues in an object choice task appears to require far less (if any) experience to develop. Overall my thesis extends our knowledge of comparative social cognition and in particular our knowledge of social cognition in Horses. Taken together, these results clearly demonstrate that Horses do indeed possess some complex socio-cognitive skills.
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Cross-modal individual recognition in Domestic Horses (Equus caballus) extends to familiar humans
Proceedings of The Royal Society B: Biological Sciences, 2012Co-Authors: Leanne Proops, Karen MccombAbstract:It has recently been shown that some non-human animals can cross-modally recognize members of their own taxon. What is unclear is just how plastic this recognition system can be. In this study, we investigate whether an animal, the Domestic Horse, is capable of spontaneous cross-modal recognition of individuals from a morphologically very different species. We also provide the first insights into how cross-modal identity information is processed by examining whether there are hemispheric biases in this important social skill. In our preferential looking paradigm, subjects were presented with two people and playbacks of their voices to determine whether they were able to match the voice with the person. When presented with familiar handlers subjects could match the specific familiar person with the correct familiar voice. Horses were significantly better at performing the matching task when the congruent person was standing on their right, indicating marked hemispheric specialization (left hemisphere bias) in this ability. These results are the first to demonstrate that cross-modal recognition in animals can extend to individuals from phylogenetically very distant species. They also indicate that processes governed by the left hemisphere are central to the cross-modal matching of visual and auditory information from familiar individuals in a naturalistic setting.
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Cross-modal individual recognition in Domestic Horses (Equus caballus).
Proceedings of the National Academy of Sciences of the United States of America, 2008Co-Authors: Leanne Proops, Karen Mccomb, David RebyAbstract:Individual recognition is considered a complex process and, although it is believed to be widespread across animal taxa, the cognitive mechanisms underlying this ability are poorly understood. An essential feature of individual recognition in humans is that it is cross-modal, allowing the matching of current sensory cues to identity with stored information about that specific individual from other modalities. Here, we use a cross-modal expectancy violation paradigm to provide a clear and systematic demonstration of cross-modal individual recognition in a nonhuman animal: the Domestic Horse. Subjects watched a herd member being led past them before the individual went of view, and a call from that or a different associate was played from a loudspeaker positioned close to the point of disappearance. When Horses were shown one associate and then the call of a different associate was played, they responded more quickly and looked significantly longer in the direction of the call than when the call matched the herd member just seen, an indication that the incongruent combination violated their expectations. Thus, Horses appear to possess a cross-modal representation of known individuals containing unique auditory and visual/olfactory information. Our paradigm could provide a powerful way to study individual recognition across a wide range of species.
Yaping Zhang - One of the best experts on this subject based on the ideXlab platform.
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complex evolutionary patterns revealed by mitochondrial genomes of the Domestic Horse
Current Molecular Medicine, 2014Co-Authors: T Ning, J Li, H Xiao, Stephen J Wylie, H Li, Yaping ZhangAbstract:The Domestic Horse is the most widely used and important stock and recreational animal, valued for its strength and endurance. The energy required by the Domestic Horse is mainly supplied by mitochondria via oxidative phosphorylation. Thus, selection may have played an essential role in the evolution of the Horse mitochondria. Besides, demographic events also affect the DNA polymorphic pattern on mitochondria. To understand the evolutionary patterns of the mitochondria of the Domestic Horse, we used a deep sequencing approach to obtain the complete sequences of 15 mitochondrial genomes, and four mitochondrial gene sequences, ND6, ATP8, ATP6 and CYTB, collected from 509, 363, 363 and 409 Domestic Horses, respectively. Evidence of strong substitution rate heterogeneity was found at nonsynonymous sites across the genomes. Signatures of recent positive selection on mtDNA of Domestic Horse were detected. Specifically, five amino acids in the four mitochondrial genes were identified as the targets of positive selection. Coalescentbased simulations imply that recent population expansion is the most probable explanation for the matrilineal population history for Domestic Horse. Our findings reveal a complex pattern of non-neutral evolution of the mitochondrial genome in the Domestic Horses. - See more at: http://www.eurekaselect.com/126582/article#sthash.kebAhpP3.dpuf
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Adaptive evolution of the mitochondrial ND6 gene in the Domestic Horse.
Genetics and Molecular Research, 2010Co-Authors: T Ning, H Xiao, Li Jc, Yaping ZhangAbstract:Mitochondria play a crucial role in energy metabolism through oxidative phosphorylation. Organisms living at high altitudes are potentially influenced by oxygen deficits and cold temperatures. The severe environmental conditions can impact on metabolism and direct selection of mitochondrial DNA. As a wide-ranging animal, the Domestic Horse (Equus caballus) has developed various morphological and physiological characteristics for adapting to different altitudes. Thus, this is a good species for studying adaption to high altitudes at a molecular level. We sequenced the complete NADH dehydrogenase 6 gene (ND6) of 509 Horses from 24 sampling locations. By comparative analysis of three Horse populations living at different altitudes (>2200 m, 1200-1700 m, and
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adaptive evolution of the mitochondrial nd6 gene in the Domestic Horse
Genetics and Molecular Research, 2010Co-Authors: T Ning, J Li, H Xiao, Yaping ZhangAbstract:Mitochondria play a crucial role in energy metabolism through oxidative phosphorylation. Organisms living at high altitudes are potentially influenced by oxygen deficits and cold temperatures. The severe environmental conditions can impact on metabolism and direct selection of mitochondrial DNA. As a wide-ranging animal, the Domestic Horse (Equus caballus) has developed various morphological and physiological characteristics for adapting to different altitudes. Thus, this is a good species for studying adaption to high altitudes at a molecular level. We sequenced the complete NADH dehydrogenase 6 gene (ND6) of 509 Horses from 24 sampling locations. By comparative analysis of three Horse populations living at different altitudes (>2200 m, 1200-1700 m, and <900 m), we found that the high-altitude population had the lowest genetic diversity and significant negative Tajima’s D; both values declined with increasing elevation. Moreover, non-directional selection was identified for the ND6 gene by a tree-based relative ratio test (P = 0.007); the highest proportion of high-altitude Horses was found distributed on the selected branches. We conclude that the high-altitude environment has directed adaptive evolution of the mitochondrial ND6 gene in the plateau Horse.
Luděk Bartos - One of the best experts on this subject based on the ideXlab platform.
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male free environment prevents pregnancy disruption in Domestic Horse mares mated away of home
Applied Animal Behaviour Science, 2017Co-Authors: Luděk Bartos, Jitka Bartosova, Jan PluhacekAbstract:Abstract In a previous study (Bartos et al., 2011) we have reported on the effects of the male social environment on the maintenance or disruption of pregnancy in Domestic mares mated away from home. In this follow-up study we compare the effects of returning to a home environment including a male (or males) to which the returning mare had, or was denied, access or did not have access, with that of returning to a home environment containing only other females. As in the previous study, we used data collected from private Horse owners in the Czech Republic. The probability of disruption of pregnancy was lowest when the mare was sharing an enclosure only with other mares. Incidence of pregnancy failure was highest when the mare was in one enclosure, while the male or males stayed in an adjacent enclosure and intermediate where females returned to a home enclosure and shared it with the home male(s). In addition, the probability of pregnancy disruption decreased with increasing number of foals delivered in the mare’s previous reproductive history.
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pregnancy disruption in artificially inseminated Domestic Horse mares as a counterstrategy against potential infanticide
Journal of Animal Science, 2015Co-Authors: Luděk Bartos, Jitka Bartosova, Jan PluhacekAbstract:In a previous study, we suggested that the common practice of transporting a mare for mating and then bringing her back to an environment that also contains males that did not sire the fetus may be a major cause of high percentages of pregnancy disruption in Domestic Horses. In this study, we tested whether disruption of pregnancies induced by AI occurs as frequently as after mating with a strange stallion away from home and is affected by the same factors in the home social environment. Based on 77 records, the probability of pregnancy disruption after AI depended on the social environment in which the mare was maintained after mating and the number of foals the mare had delivered in the past. Also after AI, as with natural matings away from home, the probability of pregnancy disruption was higher when the mare had no male company in her enclosure but stallions or geldings were present in an adjacent enclosure than when the mare was sharing the enclosure with geldings (generalized linear mixed model = 8.68, = 0.007, odds ratio = 8.17). These data support the prediction that the mare perceives conception after AI equally to natural mating with a strange stallion. The results suggested pregnancy disruption may be stimulated by the social circumstances of the home environment in mares artificially inseminated as in mares mated naturally away from home. The practical implications of this result is that after AI, to reduce risk of pregnancy disruption and improve welfare, Horse breeders should place the pregnant mare into an environment with no stallion or stallions/gelding or geldings or to an enclosure together with the male or males.
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concurrent lactation and pregnancy pregnant Domestic Horse mares do not increase mother offspring conflict during intensive lactation
PLOS ONE, 2011Co-Authors: Jitka Bartosova, Luděk Bartos, Jana Dubcová, Martina Komarkova, Jan PluhacekAbstract:Lactation is the most energy demanding part of parental care in mammals, so parent-offspring conflict arises over milk provided by the mother. In some species females commonly become pregnant shortly after parturition of previous young. This further intensifies mother-offspring conflict due to concurrent pregnancy and lactation. In equids it has been well established that pregnant females wean their foals earlier than non-pregnant ones. Intensified mother-offspring conflict was presumed to associate with pregnancy also during the period of intensive lactation, i.e., before the weaning process starts. We investigated the effect of pregnancy on suckling behaviour characteristics as indicators of mother-offspring conflict in Domestic Horses. Contrary to expectation, here we provide evidence of a decreased mother-offspring conflict related to pregnancy in lactating females during first two trimesters of pregnancy. Pregnant mares provided longer suckling bouts and did not reject or terminate suckling of their foals more often than non-pregnant mares. Our results suggest that pregnant mares cope with parallel investment into a nursed foal and a foetus through enhancing nursing behaviour in early stages of pregnancy before the initially low requirements of the foetus increase. They compensate their suckling foal with the perspective of its early weaning due to ongoing pregnancy.
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promiscuous behaviour disrupts pregnancy block in Domestic Horse mares
Behavioral Ecology and Sociobiology, 2011Co-Authors: Luděk Bartos, Jitka Bartosova, Jan Pluhacek, Jana SindelařovaAbstract:Based on questionnaires from Horse breeders, we found that bringing a pregnant mare which had been mated away from home into a vicinity of a familiar male who was not the father of her foetus increased probability of pregnancy disruption. These mares aborted in 31% of cases, while none of those mated within the home stable aborted. Repeated sexual activity either by a stallion or dominant gelding from the normal home group was observed shortly after the mare came from away-mating. Pregnant mares isolated from home males by a fence were even seen soliciting them over the fence. We speculate that, once returned to the home “herd”, and introduced to familiar males, mares were more likely to terminate their pregnancy to save energy and avoid likely future infanticidal loss of their progeny by dominant male(s) of the home social group. This is a newly discovered phenomenon where a mare manipulates the male’s paternity assessment by promiscuous mating. It may explain a common increased incidence of foetal loss in Domestic Horses occurring in nearly 40% of pregnancies. We conclude that the common practice of transporting the mare for mating and then bringing her back to an environment with males, stallions or geldings, which did not sire the foetus, is the main cause of high percentages of pregnancy disruption in Domestic Horses.