The Experts below are selected from a list of 38175 Experts worldwide ranked by ideXlab platform
Peter A Seeber - One of the best experts on this subject based on the ideXlab platform.
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Effects of life history stage and climatic conditions on fecal egg counts in plains Zebras (Equus quagga) in the Serengeti National Park
Parasitology Research, 2020Co-Authors: Peter A Seeber, Tatiana A Kuzmina, Alex D. Greenwood, Marlene Lynette EastAbstract:In wildlife, endoparasite burden can be affected by host life history stage, environmental conditions, host abundance, and parasite co-infections. We tested the effects of these factors on gastrointestinal parasite infection in plains Zebras ( Equus quagga ) in the Serengeti ecosystem, Tanzania, using fecal egg counts of two nematode families (Strongylidae and Ascarididae) and the presence/absence of cestode (Anoplocephalidae) eggs. We predicted higher egg counts of Strongylidae and Ascarididae, and increased likelihood of Anoplocephalidae infection in individuals (1) during energetically costly life history stages when resource allocation to immune processes may decrease and in young Zebras after weaning because of increased uptake of infective stages with forage, (2) when climatic conditions facilitate survival of infective stages, (3) when large zebra aggregations increase forage contamination with infective stages, and (4) in individuals co-infected with more than one parasite group as this may indicate reduced immune competence. Strongylidae egg counts were higher, and the occurrence of Anoplocephalidae eggs was more likely in bachelors than in band stallions, whereas Ascarididae egg counts were higher in band stallions. Strongylidae and Ascarididae egg counts were not increased in lactating females. Strongylidae egg counts were higher in subadults than in foals. Regardless of sex and age, Ascarididae infections were more likely under wet conditions. Co-infections did not affect Strongylidae egg counts. Ascarididae egg counts in adult females were higher when individuals were co-infected with Anoplocephalidae. We present evidence that parasite burdens in plains Zebras are affected by life history stage, environmental conditions, and co-infection.
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Immune differences in captive and free-ranging Zebras (Equus zebra and E. quagga)
Mammalian Biology, 2020Co-Authors: Peter A Seeber, Alex D. Greenwood, Thomas A. Morrison, Alix Ortega, Marion L. East, Gábor Á. CzirjákAbstract:Wild mammals in ex situ captivity experience substantially different environmental conditions compared to free-ranging conspecifics, e.g., in terms of diet, climatic conditions, social factors, movement space, and direct anthropogenic disturbance. Moreover, animals in captivity frequently undergo management interventions such as medical treatments which may influence pathogen pressure. Captivity is known to affect immunological responses in some terrestrial and marine mammals; however, it is unclear whether this can be generalized to other taxa. Furthermore, little is known about how energetically costly life history stages such as lactation influence the immune system in wildlife. We measured expression of components of the constitutive and induced innate immunity and of the adaptive immune system in plains and mountain Zebras (Equus quagga and E. zebra), including lactating and non-lactating individuals. As a proxy for general immune function, we screened for lytic equine herpesvirus (EHV) infection, a common and often latent pathogen which is reactivated in response to stress and immune challenge. Both energetically cheap markers of the constitutive innate immunity were lower in captive than in wild Zebras, whereas energetically costly markers of the induced innate immunity were more highly expressed in captive Zebras. Lactation was associated with higher titers of natural antibodies and lysozyme. Lytic EHV infection was not significantly correlated with any of the measured immune markers. Our results suggest that captivity and lactation may influence immune functions in zebra mares.
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life history stage and extrinsic factors affect behavioural time allocation in plains Zebras equus quagga in the serengeti ecosystem
Behavioral Ecology and Sociobiology, 2019Co-Authors: Peter A Seeber, Alex D. Greenwood, M. Franz, Marion L. EastAbstract:Time is a limited resource and how well it is allocated to competing behaviours can profoundly affect Darwinian fitness. Life history theory predicts that the amount of time allocated to vital behaviours will change with life history stage, resulting in trade-offs between competing behaviours. Moreover, a range of environmental factors can also affect activity budgets. We studied diurnal time allocation by migratory plains Zebras (Equus quagga) in the Serengeti ecosystem, Tanzania, and investigated the effect of life history stage, social environment, habitat structure, and day time on time allocation to five behavioural categories (grazing, resting, vigilance, movement, other). We expected (1) increased vulnerability to predation and impeded predator detection to increase vigilance and decrease resting and grazing; (2) energetically costly life stages to increase grazing and decrease resting; and (3) increasing age in young to result in increased vigilance and grazing and decreased resting. Our findings revealed that in young Zebras, resting decreased and grazing increased from the youngest to the oldest age class. Band stallions spent more time grazing and less time resting and moving than bachelors. Lactating mares devoted more time to grazing but less to resting and vigilance than other mares. Mares spent most time vigilant in the last third and stallions in the first third of the day. Adult Zebras moved more, and mares were more vigilant in the woodland boundary than on short grass plains. Taken together, our study identifies intrinsic and extrinsic factors shaping time allocation decisions and trade-offs between competing behaviours in plains zebra. SIGNIFICANCE STATEMENT: How well animals allocate their limited time to competing behaviours will affect their survival and reproduction. For example, energetically costly life history stages often require an increase in foraging whereas when predators threaten survival, more time should be allocated to vigilance. Increased investment of time in one behaviour requires decreased investment in another or other behaviours; thus, trade-offs in time are expected. Life history theory predicts substantial changes in the time allocated to vital behaviours between life stages. We investigated the effect of life history stage and environmental factors on the behavioural time budgets of migratory plains Zebras in the Serengeti ecosystem. Our results showed that life history stage, juvenile age and environmental factors determine how time is invested in vital behaviours, and the behavioural trade-offs this entails.
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Life history stage and extrinsic factors affect behavioural time allocation in plains Zebras (Equus quagga) in the Serengeti ecosystem
Behavioral Ecology and Sociobiology, 2019Co-Authors: Peter A Seeber, Alex D. Greenwood, M. Franz, Marlene Lynette EastAbstract:Time is a limited resource and how well it is allocated to competing behaviours can profoundly affect Darwinian fitness. Life history theory predicts that the amount of time allocated to vital behaviours will change with life history stage, resulting in trade-offs between competing behaviours. Moreover, a range of environmental factors can also affect activity budgets. We studied diurnal time allocation by migratory plains Zebras ( Equus quagga ) in the Serengeti ecosystem, Tanzania, and investigated the effect of life history stage, social environment, habitat structure, and day time on time allocation to five behavioural categories (grazing, resting, vigilance, movement, other). We expected (1) increased vulnerability to predation and impeded predator detection to increase vigilance and decrease resting and grazing; (2) energetically costly life stages to increase grazing and decrease resting; and (3) increasing age in young to result in increased vigilance and grazing and decreased resting. Our findings revealed that in young Zebras, resting decreased and grazing increased from the youngest to the oldest age class. Band stallions spent more time grazing and less time resting and moving than bachelors. Lactating mares devoted more time to grazing but less to resting and vigilance than other mares. Mares spent most time vigilant in the last third and stallions in the first third of the day. Adult Zebras moved more, and mares were more vigilant in the woodland boundary than on short grass plains. Taken together, our study identifies intrinsic and extrinsic factors shaping time allocation decisions and trade-offs between competing behaviours in plains zebra. Significance statement How well animals allocate their limited time to competing behaviours will affect their survival and reproduction. For example, energetically costly life history stages often require an increase in foraging whereas when predators threaten survival, more time should be allocated to vigilance. Increased investment of time in one behaviour requires decreased investment in another or other behaviours; thus, trade-offs in time are expected. Life history theory predicts substantial changes in the time allocated to vital behaviours between life stages. We investigated the effect of life history stage and environmental factors on the behavioural time budgets of migratory plains Zebras in the Serengeti ecosystem. Our results showed that life history stage, juvenile age and environmental factors determine how time is invested in vital behaviours, and the behavioural trade-offs this entails.
Alex D. Greenwood - One of the best experts on this subject based on the ideXlab platform.
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Effects of life history stage and climatic conditions on fecal egg counts in plains Zebras (Equus quagga) in the Serengeti National Park
Parasitology Research, 2020Co-Authors: Peter A Seeber, Tatiana A Kuzmina, Alex D. Greenwood, Marlene Lynette EastAbstract:In wildlife, endoparasite burden can be affected by host life history stage, environmental conditions, host abundance, and parasite co-infections. We tested the effects of these factors on gastrointestinal parasite infection in plains Zebras ( Equus quagga ) in the Serengeti ecosystem, Tanzania, using fecal egg counts of two nematode families (Strongylidae and Ascarididae) and the presence/absence of cestode (Anoplocephalidae) eggs. We predicted higher egg counts of Strongylidae and Ascarididae, and increased likelihood of Anoplocephalidae infection in individuals (1) during energetically costly life history stages when resource allocation to immune processes may decrease and in young Zebras after weaning because of increased uptake of infective stages with forage, (2) when climatic conditions facilitate survival of infective stages, (3) when large zebra aggregations increase forage contamination with infective stages, and (4) in individuals co-infected with more than one parasite group as this may indicate reduced immune competence. Strongylidae egg counts were higher, and the occurrence of Anoplocephalidae eggs was more likely in bachelors than in band stallions, whereas Ascarididae egg counts were higher in band stallions. Strongylidae and Ascarididae egg counts were not increased in lactating females. Strongylidae egg counts were higher in subadults than in foals. Regardless of sex and age, Ascarididae infections were more likely under wet conditions. Co-infections did not affect Strongylidae egg counts. Ascarididae egg counts in adult females were higher when individuals were co-infected with Anoplocephalidae. We present evidence that parasite burdens in plains Zebras are affected by life history stage, environmental conditions, and co-infection.
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Immune differences in captive and free-ranging Zebras (Equus zebra and E. quagga)
Mammalian Biology, 2020Co-Authors: Peter A Seeber, Alex D. Greenwood, Thomas A. Morrison, Alix Ortega, Marion L. East, Gábor Á. CzirjákAbstract:Wild mammals in ex situ captivity experience substantially different environmental conditions compared to free-ranging conspecifics, e.g., in terms of diet, climatic conditions, social factors, movement space, and direct anthropogenic disturbance. Moreover, animals in captivity frequently undergo management interventions such as medical treatments which may influence pathogen pressure. Captivity is known to affect immunological responses in some terrestrial and marine mammals; however, it is unclear whether this can be generalized to other taxa. Furthermore, little is known about how energetically costly life history stages such as lactation influence the immune system in wildlife. We measured expression of components of the constitutive and induced innate immunity and of the adaptive immune system in plains and mountain Zebras (Equus quagga and E. zebra), including lactating and non-lactating individuals. As a proxy for general immune function, we screened for lytic equine herpesvirus (EHV) infection, a common and often latent pathogen which is reactivated in response to stress and immune challenge. Both energetically cheap markers of the constitutive innate immunity were lower in captive than in wild Zebras, whereas energetically costly markers of the induced innate immunity were more highly expressed in captive Zebras. Lactation was associated with higher titers of natural antibodies and lysozyme. Lytic EHV infection was not significantly correlated with any of the measured immune markers. Our results suggest that captivity and lactation may influence immune functions in zebra mares.
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life history stage and extrinsic factors affect behavioural time allocation in plains Zebras equus quagga in the serengeti ecosystem
Behavioral Ecology and Sociobiology, 2019Co-Authors: Peter A Seeber, Alex D. Greenwood, M. Franz, Marion L. EastAbstract:Time is a limited resource and how well it is allocated to competing behaviours can profoundly affect Darwinian fitness. Life history theory predicts that the amount of time allocated to vital behaviours will change with life history stage, resulting in trade-offs between competing behaviours. Moreover, a range of environmental factors can also affect activity budgets. We studied diurnal time allocation by migratory plains Zebras (Equus quagga) in the Serengeti ecosystem, Tanzania, and investigated the effect of life history stage, social environment, habitat structure, and day time on time allocation to five behavioural categories (grazing, resting, vigilance, movement, other). We expected (1) increased vulnerability to predation and impeded predator detection to increase vigilance and decrease resting and grazing; (2) energetically costly life stages to increase grazing and decrease resting; and (3) increasing age in young to result in increased vigilance and grazing and decreased resting. Our findings revealed that in young Zebras, resting decreased and grazing increased from the youngest to the oldest age class. Band stallions spent more time grazing and less time resting and moving than bachelors. Lactating mares devoted more time to grazing but less to resting and vigilance than other mares. Mares spent most time vigilant in the last third and stallions in the first third of the day. Adult Zebras moved more, and mares were more vigilant in the woodland boundary than on short grass plains. Taken together, our study identifies intrinsic and extrinsic factors shaping time allocation decisions and trade-offs between competing behaviours in plains zebra. SIGNIFICANCE STATEMENT: How well animals allocate their limited time to competing behaviours will affect their survival and reproduction. For example, energetically costly life history stages often require an increase in foraging whereas when predators threaten survival, more time should be allocated to vigilance. Increased investment of time in one behaviour requires decreased investment in another or other behaviours; thus, trade-offs in time are expected. Life history theory predicts substantial changes in the time allocated to vital behaviours between life stages. We investigated the effect of life history stage and environmental factors on the behavioural time budgets of migratory plains Zebras in the Serengeti ecosystem. Our results showed that life history stage, juvenile age and environmental factors determine how time is invested in vital behaviours, and the behavioural trade-offs this entails.
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Life history stage and extrinsic factors affect behavioural time allocation in plains Zebras (Equus quagga) in the Serengeti ecosystem
Behavioral Ecology and Sociobiology, 2019Co-Authors: Peter A Seeber, Alex D. Greenwood, M. Franz, Marlene Lynette EastAbstract:Time is a limited resource and how well it is allocated to competing behaviours can profoundly affect Darwinian fitness. Life history theory predicts that the amount of time allocated to vital behaviours will change with life history stage, resulting in trade-offs between competing behaviours. Moreover, a range of environmental factors can also affect activity budgets. We studied diurnal time allocation by migratory plains Zebras ( Equus quagga ) in the Serengeti ecosystem, Tanzania, and investigated the effect of life history stage, social environment, habitat structure, and day time on time allocation to five behavioural categories (grazing, resting, vigilance, movement, other). We expected (1) increased vulnerability to predation and impeded predator detection to increase vigilance and decrease resting and grazing; (2) energetically costly life stages to increase grazing and decrease resting; and (3) increasing age in young to result in increased vigilance and grazing and decreased resting. Our findings revealed that in young Zebras, resting decreased and grazing increased from the youngest to the oldest age class. Band stallions spent more time grazing and less time resting and moving than bachelors. Lactating mares devoted more time to grazing but less to resting and vigilance than other mares. Mares spent most time vigilant in the last third and stallions in the first third of the day. Adult Zebras moved more, and mares were more vigilant in the woodland boundary than on short grass plains. Taken together, our study identifies intrinsic and extrinsic factors shaping time allocation decisions and trade-offs between competing behaviours in plains zebra. Significance statement How well animals allocate their limited time to competing behaviours will affect their survival and reproduction. For example, energetically costly life history stages often require an increase in foraging whereas when predators threaten survival, more time should be allocated to vigilance. Increased investment of time in one behaviour requires decreased investment in another or other behaviours; thus, trade-offs in time are expected. Life history theory predicts substantial changes in the time allocated to vital behaviours between life stages. We investigated the effect of life history stage and environmental factors on the behavioural time budgets of migratory plains Zebras in the Serengeti ecosystem. Our results showed that life history stage, juvenile age and environmental factors determine how time is invested in vital behaviours, and the behavioural trade-offs this entails.
Marlene Lynette East - One of the best experts on this subject based on the ideXlab platform.
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Effects of life history stage and climatic conditions on fecal egg counts in plains Zebras (Equus quagga) in the Serengeti National Park
Parasitology Research, 2020Co-Authors: Peter A Seeber, Tatiana A Kuzmina, Alex D. Greenwood, Marlene Lynette EastAbstract:In wildlife, endoparasite burden can be affected by host life history stage, environmental conditions, host abundance, and parasite co-infections. We tested the effects of these factors on gastrointestinal parasite infection in plains Zebras ( Equus quagga ) in the Serengeti ecosystem, Tanzania, using fecal egg counts of two nematode families (Strongylidae and Ascarididae) and the presence/absence of cestode (Anoplocephalidae) eggs. We predicted higher egg counts of Strongylidae and Ascarididae, and increased likelihood of Anoplocephalidae infection in individuals (1) during energetically costly life history stages when resource allocation to immune processes may decrease and in young Zebras after weaning because of increased uptake of infective stages with forage, (2) when climatic conditions facilitate survival of infective stages, (3) when large zebra aggregations increase forage contamination with infective stages, and (4) in individuals co-infected with more than one parasite group as this may indicate reduced immune competence. Strongylidae egg counts were higher, and the occurrence of Anoplocephalidae eggs was more likely in bachelors than in band stallions, whereas Ascarididae egg counts were higher in band stallions. Strongylidae and Ascarididae egg counts were not increased in lactating females. Strongylidae egg counts were higher in subadults than in foals. Regardless of sex and age, Ascarididae infections were more likely under wet conditions. Co-infections did not affect Strongylidae egg counts. Ascarididae egg counts in adult females were higher when individuals were co-infected with Anoplocephalidae. We present evidence that parasite burdens in plains Zebras are affected by life history stage, environmental conditions, and co-infection.
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Life history stage and extrinsic factors affect behavioural time allocation in plains Zebras (Equus quagga) in the Serengeti ecosystem
Behavioral Ecology and Sociobiology, 2019Co-Authors: Peter A Seeber, Alex D. Greenwood, M. Franz, Marlene Lynette EastAbstract:Time is a limited resource and how well it is allocated to competing behaviours can profoundly affect Darwinian fitness. Life history theory predicts that the amount of time allocated to vital behaviours will change with life history stage, resulting in trade-offs between competing behaviours. Moreover, a range of environmental factors can also affect activity budgets. We studied diurnal time allocation by migratory plains Zebras ( Equus quagga ) in the Serengeti ecosystem, Tanzania, and investigated the effect of life history stage, social environment, habitat structure, and day time on time allocation to five behavioural categories (grazing, resting, vigilance, movement, other). We expected (1) increased vulnerability to predation and impeded predator detection to increase vigilance and decrease resting and grazing; (2) energetically costly life stages to increase grazing and decrease resting; and (3) increasing age in young to result in increased vigilance and grazing and decreased resting. Our findings revealed that in young Zebras, resting decreased and grazing increased from the youngest to the oldest age class. Band stallions spent more time grazing and less time resting and moving than bachelors. Lactating mares devoted more time to grazing but less to resting and vigilance than other mares. Mares spent most time vigilant in the last third and stallions in the first third of the day. Adult Zebras moved more, and mares were more vigilant in the woodland boundary than on short grass plains. Taken together, our study identifies intrinsic and extrinsic factors shaping time allocation decisions and trade-offs between competing behaviours in plains zebra. Significance statement How well animals allocate their limited time to competing behaviours will affect their survival and reproduction. For example, energetically costly life history stages often require an increase in foraging whereas when predators threaten survival, more time should be allocated to vigilance. Increased investment of time in one behaviour requires decreased investment in another or other behaviours; thus, trade-offs in time are expected. Life history theory predicts substantial changes in the time allocated to vital behaviours between life stages. We investigated the effect of life history stage and environmental factors on the behavioural time budgets of migratory plains Zebras in the Serengeti ecosystem. Our results showed that life history stage, juvenile age and environmental factors determine how time is invested in vital behaviours, and the behavioural trade-offs this entails.
Claudio V. Mello - One of the best experts on this subject based on the ideXlab platform.
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ZEBrA: Zebra finch Expression Brain Atlas-A resource for comparative molecular neuroanatomy and brain evolution studies.
Journal of Comparative Neurology, 2020Co-Authors: Peter V. Lovell, Morgan Wirthlin, Taylor Kaser, Alexa A. Buckner, Julia B. Carleton, Brian R. Snider, Anne Mchugh, Alexander Tolpygo, Partha P. Mitra, Claudio V. MelloAbstract:An in-depth understanding of the genetics and evolution of brain function and behavior requires detailed mapping of gene expression in functional brain circuits across major vertebrate clades. Here we present the Zebra finch Expression Brain Atlas (ZEBrA; www.zebrafinchatlas.org, RRID: SCR_012988), a web-based resource that maps the expression of genes linked to a broad range of functions onto the brain of zebra finches. ZEBrA is a first of its kind gene expression brain atlas for a bird species, and a first for any sauropsid. ZEBrA's >3,200 high-resolution digital images of in situ hybridized sections for ~650 genes (as of June, 2019) are presented in alignment with an annotated histological atlas and can be browsed down to cellular resolution. An extensive relational database connects expression patterns to information about gene function, mouse expression patterns and phenotypes, and gene involvement in human diseases and communication disorders. By enabling brain-wide gene expression assessments in a bird, ZEBrA provides important substrates for comparative neuroanatomy and molecular brain evolution studies. ZEBrA also provides unique opportunities for linking genetic pathways to vocal learning and motor control circuits, as well as for novel insights into the molecular basis of sex steroids actions, brain dimorphisms, reproductive and social behaviors, sleep function, and adult neurogenesis, among other fundamental themes. This article is protected by copyright. All rights reserved.
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ZEBrA: Zebra finch Expression Brain Atlas—A resource for comparative molecular neuroanatomy and brain evolution studies
The Journal of comparative neurology, 2020Co-Authors: Peter V. Lovell, Morgan Wirthlin, Taylor Kaser, Alexa A. Buckner, Julia B. Carleton, Brian R. Snider, Anne Mchugh, Alexander Tolpygo, Partha P. Mitra, Claudio V. MelloAbstract:An in-depth understanding of the genetics and evolution of brain function and behavior requires detailed mapping of gene expression in functional brain circuits across major vertebrate clades. Here we present the Zebra finch Expression Brain Atlas (ZEBrA; www.zebrafinchatlas.org, RRID: SCR_012988), a web-based resource that maps the expression of genes linked to a broad range of functions onto the brain of zebra finches. ZEBrA is a first of its kind gene expression brain atlas for a bird species, and a first for any sauropsid. ZEBrA's >3,200 high-resolution digital images of in situ hybridized sections for ~650 genes (as of June, 2019) are presented in alignment with an annotated histological atlas and can be browsed down to cellular resolution. An extensive relational database connects expression patterns to information about gene function, mouse expression patterns and phenotypes, and gene involvement in human diseases and communication disorders. By enabling brain-wide gene expression assessments in a bird, ZEBrA provides important substrates for comparative neuroanatomy and molecular brain evolution studies. ZEBrA also provides unique opportunities for linking genetic pathways to vocal learning and motor control circuits, as well as for novel insights into the molecular basis of sex steroids actions, brain dimorphisms, reproductive and social behaviors, sleep function, and adult neurogenesis, among other fundamental themes. This article is protected by copyright. All rights reserved.
Marion L. East - One of the best experts on this subject based on the ideXlab platform.
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Immune differences in captive and free-ranging Zebras (Equus zebra and E. quagga)
Mammalian Biology, 2020Co-Authors: Peter A Seeber, Alex D. Greenwood, Thomas A. Morrison, Alix Ortega, Marion L. East, Gábor Á. CzirjákAbstract:Wild mammals in ex situ captivity experience substantially different environmental conditions compared to free-ranging conspecifics, e.g., in terms of diet, climatic conditions, social factors, movement space, and direct anthropogenic disturbance. Moreover, animals in captivity frequently undergo management interventions such as medical treatments which may influence pathogen pressure. Captivity is known to affect immunological responses in some terrestrial and marine mammals; however, it is unclear whether this can be generalized to other taxa. Furthermore, little is known about how energetically costly life history stages such as lactation influence the immune system in wildlife. We measured expression of components of the constitutive and induced innate immunity and of the adaptive immune system in plains and mountain Zebras (Equus quagga and E. zebra), including lactating and non-lactating individuals. As a proxy for general immune function, we screened for lytic equine herpesvirus (EHV) infection, a common and often latent pathogen which is reactivated in response to stress and immune challenge. Both energetically cheap markers of the constitutive innate immunity were lower in captive than in wild Zebras, whereas energetically costly markers of the induced innate immunity were more highly expressed in captive Zebras. Lactation was associated with higher titers of natural antibodies and lysozyme. Lytic EHV infection was not significantly correlated with any of the measured immune markers. Our results suggest that captivity and lactation may influence immune functions in zebra mares.
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life history stage and extrinsic factors affect behavioural time allocation in plains Zebras equus quagga in the serengeti ecosystem
Behavioral Ecology and Sociobiology, 2019Co-Authors: Peter A Seeber, Alex D. Greenwood, M. Franz, Marion L. EastAbstract:Time is a limited resource and how well it is allocated to competing behaviours can profoundly affect Darwinian fitness. Life history theory predicts that the amount of time allocated to vital behaviours will change with life history stage, resulting in trade-offs between competing behaviours. Moreover, a range of environmental factors can also affect activity budgets. We studied diurnal time allocation by migratory plains Zebras (Equus quagga) in the Serengeti ecosystem, Tanzania, and investigated the effect of life history stage, social environment, habitat structure, and day time on time allocation to five behavioural categories (grazing, resting, vigilance, movement, other). We expected (1) increased vulnerability to predation and impeded predator detection to increase vigilance and decrease resting and grazing; (2) energetically costly life stages to increase grazing and decrease resting; and (3) increasing age in young to result in increased vigilance and grazing and decreased resting. Our findings revealed that in young Zebras, resting decreased and grazing increased from the youngest to the oldest age class. Band stallions spent more time grazing and less time resting and moving than bachelors. Lactating mares devoted more time to grazing but less to resting and vigilance than other mares. Mares spent most time vigilant in the last third and stallions in the first third of the day. Adult Zebras moved more, and mares were more vigilant in the woodland boundary than on short grass plains. Taken together, our study identifies intrinsic and extrinsic factors shaping time allocation decisions and trade-offs between competing behaviours in plains zebra. SIGNIFICANCE STATEMENT: How well animals allocate their limited time to competing behaviours will affect their survival and reproduction. For example, energetically costly life history stages often require an increase in foraging whereas when predators threaten survival, more time should be allocated to vigilance. Increased investment of time in one behaviour requires decreased investment in another or other behaviours; thus, trade-offs in time are expected. Life history theory predicts substantial changes in the time allocated to vital behaviours between life stages. We investigated the effect of life history stage and environmental factors on the behavioural time budgets of migratory plains Zebras in the Serengeti ecosystem. Our results showed that life history stage, juvenile age and environmental factors determine how time is invested in vital behaviours, and the behavioural trade-offs this entails.
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antibodies against equine herpesviruses and equine arteritis virus in burchell s Zebras equus burchelli from the serengeti ecosystem
Journal of Wildlife Diseases, 2005Co-Authors: Kerstin Borchers, Harald Wiik, Kai Frolich, Hanns Ludwig, Marion L. EastAbstract:A total of 51 sera from a migratory population of Burchell's Zebras (Equus burchelli) were collected in the Serengeti National Park (Tanzania) between 1999 and 2001 to assess levels of exposure to equine herpesvirus types 1, 2, 4, 9 (EHV-1, −2, −4, −9), EHV-1 zebra isolate T965, and equine arteritis virus (EAV). Using virus-specific neutralizing antibody tests, seroprevalence was high for EHV-9 (60% of 45), moderate for EAV (24% of 51), and lower for the EHV-1-related zebra isolate (17% of 41), EHV-1 (14% of 49), and EHV-4 (2% of 50). No evidence for exposure to EHV-2 was found (0% of 51). The high level of exposure to EHV-9 is interesting because evidence of infection with this virus has not been previously described in any wild equine population. Although the epidemiology of EHV-9 in Burchell's Zebras is presently unknown, our results suggest that in East Africa, this species may be a natural host of EHV-9, a neuropathogenic virus that was only recently isolated from captive Thomson's gazelles (Gazella ...
