The Experts below are selected from a list of 9969 Experts worldwide ranked by ideXlab platform
Terry L. Maple - One of the best experts on this subject based on the ideXlab platform.
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Preference for structural environmental features in captive lowland Gorillas (Gorilla Gorilla Gorilla)
Zoo Biology, 2005Co-Authors: Jacqueline J. Ogden, Donald G. Lindburg, Terry L. MapleAbstract:Increased interest in the behavioral effects of captive environments and advances in zoo design have resulted in a proliferation of “naturalistic” animal habitats. Although scientists have demonstrated that such exhibits have some positive effects on behavior, very little is known about the complex relationships between these specialized environments and behavior. This study sought to determine preferences for structural environmental features, such as slope and trees, exhibited by captive lowland Gorillas (Gorilla Gorilla Gorilla). An average of 496 location scans were collected on each of 23 Gorillas, housed in 6 groups. The results indicate that enclosure usage was significantly associated with the features of slope, nearness to holding facility, and presence of environmental components additional to substrate (e.g., tree or rock). In particular, areas with flat ground that were near the holding building and that included at least one component additional to substrate were preferred by all animals. © 1993 Wiley-Liss, Inc.
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Notes on the introduction of an 11 week-old infant Western lowland Gorilla Gorilla Gorilla Gorilla to a non-lactating surrogate mother sat Zoo Atlanta
International Zoo Yearbook, 2005Co-Authors: Michael P. Hoff, L. R. Tarou, C. Horton, L. Mayo, Terry L. MapleAbstract:In summer 1998 a ♂ infant Western lowland Gorilla Gorilla Gorilla Gorilla at Zoo Atlanta was hand-reared and integrated into a social group. Because the biological mother would not accept the infant, he was introduced to a non-lactating surrogate mother. Gorilla infants are usually ≥ 6 months old at the time of introduction but this infant was successfully introduced to the surrogate at only 11 weeks of age. Behavioural observations made during the first year of development indicate that this infant's behaviour is similar to that of mother-reared Gorillas and he shows no signs of abnormal or stereotyped behaviour. The choice of surrogate mother, the training of both the surrogate and infant for bottle feeding, and the dedication of the nursery-care staff who worked long hours to provide the infant with a stimulating nursery environment, all contributed to the success of the introduction.
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Behavioural response of a Western lowland Gorilla Gorilla Gorilla Gorilla group to the loss of the silverback male at Zoo Atlanta
International Zoo Yearbook, 1998Co-Authors: Michael P. Hoff, K. T. Hoff, Terry L. MapleAbstract:At Zoo Atlanta in December 1994 a silverback ♂ Western lowland Gorilla Gorilla Gorilla Gorilla group leader died of cardiovascular disease. The behavioural responses of the remaining members of the group were studied and a variety of individual and social behaviours was recorded. For 3 months following the death of the ♂ there was a significant increase in aggressive display behaviours, such as lunge, quadrupedal stiff stance, displace and head divert, and the mother-offspring relationship intensified. An understanding of the ‘control role’ of the silverback ♂ and the behaviour of group members following changes in social group structure can help zoo managers plan their management strategy when periods of social change are unavoidable.
Eric J. Petit - One of the best experts on this subject based on the ideXlab platform.
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Sex‐biased dispersal in western lowland Gorillas (Gorilla Gorilla Gorilla)
Molecular Ecology, 2007Co-Authors: Mélanie Douadi, Magdalena Bermejo, Sylvain Gatti, Florence Levréro, Gaëtan Duhamel, Dominique Vallet, Nelly Ménard, Eric J. PetitAbstract:We explored two hypotheses related to potential differences between sexes in dispersal behaviour in western lowland Gorillas (Gorilla Gorilla Gorilla). Direct observations suggest that immature females have more opportunities to move between breeding groups than immature males. The distribution of kin dyadic relationships within and between groups does not, however, support this hypothesis. At larger geographical scales, dispersal is likely to be easier for males than females because of the solitary phase most blackbacks experience before founding their own breeding group. However, previous work indicates that males settle preferentially close to male kin. By specifically tracing female and male lineages with mitochondrial and Y-chromosomal genetic markers, we found that male Gorillas in the 6000 km(2) area we surveyed form a single population whereas females are restricted to the individual sites we sampled and do not freely move around this area. These differences are more correctly described as differences in dispersal distances, rather than differences in dispersal rates between sexes (both sexes emigrate from their natal group in this species). Differences in resource competition and dispersal costs between female and male Gorillas are compatible with the observed pattern, but more work is needed to understand if these ultimate causes are responsible for sex-biased dispersal distances in western lowland Gorillas.
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Sex-biased dispersal in western lowland Gorillas (Gorilla Gorilla Gorilla).
Molecular Ecology, 2007Co-Authors: Mélanie Douadi, Magdalena Bermejo, Sylvain Gatti, Florence Levréro, Gaëtan Duhamel, Dominique Vallet, Nelly Ménard, Eric J. PetitAbstract:We explored two hypotheses related to potential differences between sexes in dispersal behaviour in western lowland Gorillas (Gorilla Gorilla Gorilla). Direct observations suggest that immature females have more opportunities to move between breeding groups than immature males. The distribution of kin dyadic relationships within and between groups does not, however, support this hypothesis. At larger geographical scales, dispersal is likely to be easier for males than females because of the solitary phase most blackbacks experience before founding their own breeding group. However, previous work indicates that males settle preferentially close to male kin. By specifically tracing female and male lineages with mitochondrial and Y-chromosomal genetic markers, we found that male Gorillas in the 6000 km(2) area we surveyed form a single population whereas females are restricted to the individual sites we sampled and do not freely move around this area. These differences are more correctly described as differences in dispersal distances, rather than differences in dispersal rates between sexes (both sexes emigrate from their natal group in this species). Differences in resource competition and dispersal costs between female and male Gorillas are compatible with the observed pattern, but more work is needed to understand if these ultimate causes are responsible for sex-biased dispersal distances in western lowland Gorillas.
Michael P. Hoff - One of the best experts on this subject based on the ideXlab platform.
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Notes on the introduction of an 11 week-old infant Western lowland Gorilla Gorilla Gorilla Gorilla to a non-lactating surrogate mother sat Zoo Atlanta
International Zoo Yearbook, 2005Co-Authors: Michael P. Hoff, L. R. Tarou, C. Horton, L. Mayo, Terry L. MapleAbstract:In summer 1998 a ♂ infant Western lowland Gorilla Gorilla Gorilla Gorilla at Zoo Atlanta was hand-reared and integrated into a social group. Because the biological mother would not accept the infant, he was introduced to a non-lactating surrogate mother. Gorilla infants are usually ≥ 6 months old at the time of introduction but this infant was successfully introduced to the surrogate at only 11 weeks of age. Behavioural observations made during the first year of development indicate that this infant's behaviour is similar to that of mother-reared Gorillas and he shows no signs of abnormal or stereotyped behaviour. The choice of surrogate mother, the training of both the surrogate and infant for bottle feeding, and the dedication of the nursery-care staff who worked long hours to provide the infant with a stimulating nursery environment, all contributed to the success of the introduction.
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Behavioural response of a Western lowland Gorilla Gorilla Gorilla Gorilla group to the loss of the silverback male at Zoo Atlanta
International Zoo Yearbook, 1998Co-Authors: Michael P. Hoff, K. T. Hoff, Terry L. MapleAbstract:At Zoo Atlanta in December 1994 a silverback ♂ Western lowland Gorilla Gorilla Gorilla Gorilla group leader died of cardiovascular disease. The behavioural responses of the remaining members of the group were studied and a variety of individual and social behaviours was recorded. For 3 months following the death of the ♂ there was a significant increase in aggressive display behaviours, such as lunge, quadrupedal stiff stance, displace and head divert, and the mother-offspring relationship intensified. An understanding of the ‘control role’ of the silverback ♂ and the behaviour of group members following changes in social group structure can help zoo managers plan their management strategy when periods of social change are unavoidable.
Mélanie Douadi - One of the best experts on this subject based on the ideXlab platform.
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Sex‐biased dispersal in western lowland Gorillas (Gorilla Gorilla Gorilla)
Molecular Ecology, 2007Co-Authors: Mélanie Douadi, Magdalena Bermejo, Sylvain Gatti, Florence Levréro, Gaëtan Duhamel, Dominique Vallet, Nelly Ménard, Eric J. PetitAbstract:We explored two hypotheses related to potential differences between sexes in dispersal behaviour in western lowland Gorillas (Gorilla Gorilla Gorilla). Direct observations suggest that immature females have more opportunities to move between breeding groups than immature males. The distribution of kin dyadic relationships within and between groups does not, however, support this hypothesis. At larger geographical scales, dispersal is likely to be easier for males than females because of the solitary phase most blackbacks experience before founding their own breeding group. However, previous work indicates that males settle preferentially close to male kin. By specifically tracing female and male lineages with mitochondrial and Y-chromosomal genetic markers, we found that male Gorillas in the 6000 km(2) area we surveyed form a single population whereas females are restricted to the individual sites we sampled and do not freely move around this area. These differences are more correctly described as differences in dispersal distances, rather than differences in dispersal rates between sexes (both sexes emigrate from their natal group in this species). Differences in resource competition and dispersal costs between female and male Gorillas are compatible with the observed pattern, but more work is needed to understand if these ultimate causes are responsible for sex-biased dispersal distances in western lowland Gorillas.
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Sex-biased dispersal in western lowland Gorillas (Gorilla Gorilla Gorilla).
Molecular Ecology, 2007Co-Authors: Mélanie Douadi, Magdalena Bermejo, Sylvain Gatti, Florence Levréro, Gaëtan Duhamel, Dominique Vallet, Nelly Ménard, Eric J. PetitAbstract:We explored two hypotheses related to potential differences between sexes in dispersal behaviour in western lowland Gorillas (Gorilla Gorilla Gorilla). Direct observations suggest that immature females have more opportunities to move between breeding groups than immature males. The distribution of kin dyadic relationships within and between groups does not, however, support this hypothesis. At larger geographical scales, dispersal is likely to be easier for males than females because of the solitary phase most blackbacks experience before founding their own breeding group. However, previous work indicates that males settle preferentially close to male kin. By specifically tracing female and male lineages with mitochondrial and Y-chromosomal genetic markers, we found that male Gorillas in the 6000 km(2) area we surveyed form a single population whereas females are restricted to the individual sites we sampled and do not freely move around this area. These differences are more correctly described as differences in dispersal distances, rather than differences in dispersal rates between sexes (both sexes emigrate from their natal group in this species). Differences in resource competition and dispersal costs between female and male Gorillas are compatible with the observed pattern, but more work is needed to understand if these ultimate causes are responsible for sex-biased dispersal distances in western lowland Gorillas.
Suzanne E. Macdonald - One of the best experts on this subject based on the ideXlab platform.
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spatial memory and foraging competition in captive western lowland Gorillas Gorilla Gorilla Gorilla
Primates, 2000Co-Authors: Stephanie Gibeault, Suzanne E. MacdonaldAbstract:Spatial memory and foraging competition were investigated in three mother/offspring pairs of western lowland Gorillas,Gorilla Gorilla Gorilla, using a naturalistic foraging task at the Toronto Zoo. Sixteen permanent food sites were placed throughout the animals' enclosures. All of the sites were baited and a pair of animals was free to visit the sites and collect the food. Five of the subjects collected the food with accuracy better than chance. Most of the subjects visited the sites using a pattern, and for half the subjects this was one of adjacency. The high accuracy of five of the subjects and the lack of a consistent adjacency pattern suggest that the animals did in fact use spatial memory. Furthermore, the Gorillas tended to avoid visiting food sites that had been previously depleted by their partner. They also appeared to split their search of the enclosures, each visiting only a proportion of the food sites. This indicated that the animals were competing and altering their foraging behaviour based on the behaviour of their partner. Therefore, accuracy was recalculated to take this into account. When the sites depleted by either animal in a pair during a given trial were worked into the accuracy calculations for individual animals, three of the animals still maintained accuracy above chance. This suggests that the animals were not only able to remember which sites they had depleted, but those sites depleted by their foraging partner as well.
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Gorillas' (Gorilla Gorilla Gorilla) spatial memory in a foraging task.
Journal of Comparative Psychology, 1994Co-Authors: Suzanne E. MacdonaldAbstract:The spatial memory of 2 Gorillas (Gorilla Gorilla Gorilla) was explored in a simulated foraging task. Trials consisted of 2 parts separated by a delay. In the 1st part, half of the total number of food sites were baited with a highly preferred food, and the subject was allowed to search, find, and consume these items (search phase). During the delay the same locations were again baited. After the delay the animal was reintroduced to the test enclosure and allowed to search through the sites again (re-search phase). In Experiment 1, an adult Gorilla was very accurate in remembering locations that had previously contained food at delay intervals of 24 hr or more. In Experiment 2, a juvenile Gorilla was also accurate in remembering locations that had previously contained food at delays up to 10 min. The adult Gorilla appeared to use a counting strategy during the search phase to minimize the number of sites visited.
