The Experts below are selected from a list of 1974 Experts worldwide ranked by ideXlab platform
David W Macdonald - One of the best experts on this subject based on the ideXlab platform.
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A non-invasive method to assess the reproductive status of the European Badger (Meles meles) from urinary sex-steroid metabolites
General and comparative endocrinology, 2020Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Martin Dehnhard, Christina D BueschingAbstract:Abstract Due to their unique reproductive physiology and behaviour, European Badgers (Meles meles) are often used as a model to study mammalian reproduction. For reproductive endocrinology, circulating hormone levels are conventionally measured directly from blood samples. However, routine blood sampling is often not practical for wild animals and may induce stress affecting measurement accuracy. Non-invasive alternatives are thus of interest. Circulating hormones are metabolized through different routes, either by the kidneys, to be excreted through urine, or by the liver, to be excreted through faeces. These metabolites can thus be used as a proxy of hormone measurements, provided the species-specific metabolic characteristics are known. Here we tested the suitability of measuring urinary metabolites of circulating plasma sex-steroid hormones (testosterone in males and oestrogen in females) with enzyme immunoassays to assess the reproductive status of the European Badger (Meles meles). Biological validation evidenced that urinary testosterone metabolite (UTM) and urinary total oestrogen metabolite (UEM) excretion patterns both corresponded with seasonal Badger reproductive patterns on a population level, signaling correlation over a broad time frame. On an individual level, concurrent sampling of urine and plasma showed that male plasma testosterone and UTM levels correlated significantly across seasons, but no short term correlation was evident for total oestrogen and UEM in females. Thus, in Badgers, urinary sex-steroid metabolites can be used reliably in the short term to assess male reproductive status at the individual level, but only at the broader population level for females.
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reproductive and somatic senescence in the European Badger meles meles evidence from lifetime sex steroid profiles
Zoology, 2020Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Abstract Among the Carnivora, there is sparse evidence for any substantive fitness benefits of post reproductive lifespan (PRLS, survival after reproductive cessation, RC). Using the European Badger (Meles meles) as a model species, we analyzed sex-specific cross-sectional endocrinological and morphological data to investigate: 1) age-dependent reproductive decline in sex-steroid levels versus prime reproductive age; 2) age-dependent declines in somatic condition and reproductive advertisement (from subcaudal scent gland secretion); 3) changes in reproductive success with age due to somatic and endocrinological decline; 4) occurrence of RC, PRLS, and post reproductive representation (PrR) in the population with reference to pre-pubescent hormone levels and evidenced by fewer cub assignments from pedigree. We provide strong evidence for a gradual, not abrupt, decline in sex-steroid levels with age, with both sexes following a concave (down) quadratic trend. For both sexes, the onset of decline in somatic condition commenced at the age of 3 years. In contrast, decline in reproductive hormones started at age ca. 5.5 years in females and 6 years in males, with similar rates of decline thereafter. Subcaudal gland secretion volume also decreased in both sexes, especially after age 5, suggesting less investment in reproductive advertisement. After age 3, fewer (surviving) females were assigned cubs. This coincided with the onset of somatic decline but came earlier than hormonal decline (5.5 years onwards). The decrease in offspring assignments commenced later in males at age 5-6 years; concomitant with onset of testosterone decline at 6 years. This suggests that, contrary to females, in males declining body condition does not preclude reproductive success (no ‘restraint’) in advance of hormonal senescence (‘constraint’). There was evidence of female PRLS, with very old adults living up to 2.59 ± 1.29 years after RC; although in males this evidence was weaker. We discuss the implications of these findings for RC and PRLS in the context of adaptive and non-adaptive hypotheses. There was evidence of over 2 years of Post Reproductive Life Span in both sexes.
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Male European Badger churrs: insights into call function and motivational basis
Mammalian Biology, 2020Co-Authors: Benjamin D. Charlton, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Determining the contexts of emission and information content of vocal signals can yield insights into the function of different call types, and remains an important step towards understanding the diversification of mammalian vocal repertoires. In this study, we used infra-red video cameras and remote audio recorders to document seasonal and contextual variation in male European Badger ( Meles meles ) churr production over a 24-month period, and acoustic analysis based on source-filter theory to examine whether churr acoustic structure varies according to the caller’s arousal state and identity. Our behavioural observations revealed that male churrs are produced almost exclusively during the breeding season. Further contextual analysis showed that males emit churrs during close-range interactions with female conspecifics, often during copulation attempts, and churr directly into sett entrances. In addition, males involved in close-range social interactions delivered churrs with more call units per second than those vocalising without other conspecifics in close proximity. Discriminant function analysis also revealed that male churrs are individually distinctive, and confirmed that the formants (vocal tract resonances) contribute the most to caller identity. These findings indicate that Badger churrs are sexual calls with the potential to signal male arousal state and identity in reproductive contexts. They also add to an increasing body of literature on the importance of formants for identity cueing in nonhuman mammals.
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heterochrony of puberty in the European Badger meles meles can be explained by growth rate and group size evidence for two endocrinological phenotypes
PLOS ONE, 2019Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Puberty is a key stage in mammalian ontogeny, involving endocrinological, physiological and behavioural changes, moderated by intrinsic and extrinsic factors. Thus, not all individuals within one population achieve sexual maturity simultaneously. Here, using the European Badger (Meles meles) as a model, we describe male testosterone and female oestrone profiles (using Enzyme-immunoassays) from first capture (3 months, post-weaning) until 28 months (attaining sexual maturity and final body size), along with metrics of somatic growth, scent gland development and maturation of external reproductive organs as well as intra-specific competition. In both sexes, endocrinological puberty commenced at ca. 11 months. Thereafter, cub hormone levels followed adult seasonal hormone patterns but at lower levels, with the majority of cubs reaching sexual maturity during their second mating season (22-28 months). Interestingly, there was evidence for two endocrinological phenotypes among male cubs (less evident in females), with early developers reaching sexual maturity at 11 months (first mating season) and late developers reaching sexual maturity at 22-26 months (second mating season). Early developers also attained a greater proportion of their ultimate adult size by 11 months, exhibiting faster growth rates than late developers (despite having similar adult size). Male cubs born into larger social groups tended to follow the late developer phenotype. Our results support the hypothesis that a minimum body size is required to reach sexual maturity, which may be achieved at different ages, even within a single population, where early maturity can confer individual fitness advantages and enhance population growth rate.
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effects of weather conditions on oxidative stress oxidative damage and antioxidant capacity in a wild living mammal the European Badger meles meles
Physiological and Biochemical Zoology, 2018Co-Authors: Kirstin Bilham, Christina D Buesching, Chris Newman, Michael J Noonan, Amy Boyd, Adrian Smith, David W MacdonaldAbstract:Wild-living animals are subject to weather variability that may cause the generation of reactive oxygen species, resulting in oxidative stress and tissue damage, potentially driving demographic responses. Our 3-yr field study investigated the effects of seasonal weather conditions on biomarkers for oxidative stress, oxidative damage, and antioxidant defense in the European Badger (Meles meles). We found age class effects: cubs were more susceptible to oxidative stress and oxidative damage than adults, especially very young cubs in the spring, when they also exhibited lower antioxidant biomarkers than adults. Although previous studies have found that intermediate spring and summer rainfall and warmer temperatures favor cub survival, counterintuitively these conditions were associated with more severe oxidative damage. Oxidative damage was high in cubs even when antioxidant biomarkers were high. In contrast, adult responses accorded with previous survival analyses. Wetter spring and summer conditions were associated with higher oxidative damage, but they were also associated with higher antioxidant biomarkers. Autumnal weather did not vary substantially from normative values, and thus effects were muted. Winter carryover effects were partially evident, with drier and milder conditions associated with greater oxidative damage in the following spring but also with higher antioxidant capacity. Plausibly, warmer conditions promoted more Badger activity, with associated metabolic costs at a time of year when food supply is limited. Modeling biomarkers against projected climate change scenarios predicted greater future risks of oxidative damage, although not necessarily exceeding antioxidant capacity. This interdisciplinary approach demonstrates that individual adaptive physiological responses are associated with variation in natural environmental conditions.
Chris Newman - One of the best experts on this subject based on the ideXlab platform.
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A non-invasive method to assess the reproductive status of the European Badger (Meles meles) from urinary sex-steroid metabolites
General and comparative endocrinology, 2020Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Martin Dehnhard, Christina D BueschingAbstract:Abstract Due to their unique reproductive physiology and behaviour, European Badgers (Meles meles) are often used as a model to study mammalian reproduction. For reproductive endocrinology, circulating hormone levels are conventionally measured directly from blood samples. However, routine blood sampling is often not practical for wild animals and may induce stress affecting measurement accuracy. Non-invasive alternatives are thus of interest. Circulating hormones are metabolized through different routes, either by the kidneys, to be excreted through urine, or by the liver, to be excreted through faeces. These metabolites can thus be used as a proxy of hormone measurements, provided the species-specific metabolic characteristics are known. Here we tested the suitability of measuring urinary metabolites of circulating plasma sex-steroid hormones (testosterone in males and oestrogen in females) with enzyme immunoassays to assess the reproductive status of the European Badger (Meles meles). Biological validation evidenced that urinary testosterone metabolite (UTM) and urinary total oestrogen metabolite (UEM) excretion patterns both corresponded with seasonal Badger reproductive patterns on a population level, signaling correlation over a broad time frame. On an individual level, concurrent sampling of urine and plasma showed that male plasma testosterone and UTM levels correlated significantly across seasons, but no short term correlation was evident for total oestrogen and UEM in females. Thus, in Badgers, urinary sex-steroid metabolites can be used reliably in the short term to assess male reproductive status at the individual level, but only at the broader population level for females.
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reproductive and somatic senescence in the European Badger meles meles evidence from lifetime sex steroid profiles
Zoology, 2020Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Abstract Among the Carnivora, there is sparse evidence for any substantive fitness benefits of post reproductive lifespan (PRLS, survival after reproductive cessation, RC). Using the European Badger (Meles meles) as a model species, we analyzed sex-specific cross-sectional endocrinological and morphological data to investigate: 1) age-dependent reproductive decline in sex-steroid levels versus prime reproductive age; 2) age-dependent declines in somatic condition and reproductive advertisement (from subcaudal scent gland secretion); 3) changes in reproductive success with age due to somatic and endocrinological decline; 4) occurrence of RC, PRLS, and post reproductive representation (PrR) in the population with reference to pre-pubescent hormone levels and evidenced by fewer cub assignments from pedigree. We provide strong evidence for a gradual, not abrupt, decline in sex-steroid levels with age, with both sexes following a concave (down) quadratic trend. For both sexes, the onset of decline in somatic condition commenced at the age of 3 years. In contrast, decline in reproductive hormones started at age ca. 5.5 years in females and 6 years in males, with similar rates of decline thereafter. Subcaudal gland secretion volume also decreased in both sexes, especially after age 5, suggesting less investment in reproductive advertisement. After age 3, fewer (surviving) females were assigned cubs. This coincided with the onset of somatic decline but came earlier than hormonal decline (5.5 years onwards). The decrease in offspring assignments commenced later in males at age 5-6 years; concomitant with onset of testosterone decline at 6 years. This suggests that, contrary to females, in males declining body condition does not preclude reproductive success (no ‘restraint’) in advance of hormonal senescence (‘constraint’). There was evidence of female PRLS, with very old adults living up to 2.59 ± 1.29 years after RC; although in males this evidence was weaker. We discuss the implications of these findings for RC and PRLS in the context of adaptive and non-adaptive hypotheses. There was evidence of over 2 years of Post Reproductive Life Span in both sexes.
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Male European Badger churrs: insights into call function and motivational basis
Mammalian Biology, 2020Co-Authors: Benjamin D. Charlton, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Determining the contexts of emission and information content of vocal signals can yield insights into the function of different call types, and remains an important step towards understanding the diversification of mammalian vocal repertoires. In this study, we used infra-red video cameras and remote audio recorders to document seasonal and contextual variation in male European Badger ( Meles meles ) churr production over a 24-month period, and acoustic analysis based on source-filter theory to examine whether churr acoustic structure varies according to the caller’s arousal state and identity. Our behavioural observations revealed that male churrs are produced almost exclusively during the breeding season. Further contextual analysis showed that males emit churrs during close-range interactions with female conspecifics, often during copulation attempts, and churr directly into sett entrances. In addition, males involved in close-range social interactions delivered churrs with more call units per second than those vocalising without other conspecifics in close proximity. Discriminant function analysis also revealed that male churrs are individually distinctive, and confirmed that the formants (vocal tract resonances) contribute the most to caller identity. These findings indicate that Badger churrs are sexual calls with the potential to signal male arousal state and identity in reproductive contexts. They also add to an increasing body of literature on the importance of formants for identity cueing in nonhuman mammals.
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heterochrony of puberty in the European Badger meles meles can be explained by growth rate and group size evidence for two endocrinological phenotypes
PLOS ONE, 2019Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Puberty is a key stage in mammalian ontogeny, involving endocrinological, physiological and behavioural changes, moderated by intrinsic and extrinsic factors. Thus, not all individuals within one population achieve sexual maturity simultaneously. Here, using the European Badger (Meles meles) as a model, we describe male testosterone and female oestrone profiles (using Enzyme-immunoassays) from first capture (3 months, post-weaning) until 28 months (attaining sexual maturity and final body size), along with metrics of somatic growth, scent gland development and maturation of external reproductive organs as well as intra-specific competition. In both sexes, endocrinological puberty commenced at ca. 11 months. Thereafter, cub hormone levels followed adult seasonal hormone patterns but at lower levels, with the majority of cubs reaching sexual maturity during their second mating season (22-28 months). Interestingly, there was evidence for two endocrinological phenotypes among male cubs (less evident in females), with early developers reaching sexual maturity at 11 months (first mating season) and late developers reaching sexual maturity at 22-26 months (second mating season). Early developers also attained a greater proportion of their ultimate adult size by 11 months, exhibiting faster growth rates than late developers (despite having similar adult size). Male cubs born into larger social groups tended to follow the late developer phenotype. Our results support the hypothesis that a minimum body size is required to reach sexual maturity, which may be achieved at different ages, even within a single population, where early maturity can confer individual fitness advantages and enhance population growth rate.
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effects of weather conditions on oxidative stress oxidative damage and antioxidant capacity in a wild living mammal the European Badger meles meles
Physiological and Biochemical Zoology, 2018Co-Authors: Kirstin Bilham, Christina D Buesching, Chris Newman, Michael J Noonan, Amy Boyd, Adrian Smith, David W MacdonaldAbstract:Wild-living animals are subject to weather variability that may cause the generation of reactive oxygen species, resulting in oxidative stress and tissue damage, potentially driving demographic responses. Our 3-yr field study investigated the effects of seasonal weather conditions on biomarkers for oxidative stress, oxidative damage, and antioxidant defense in the European Badger (Meles meles). We found age class effects: cubs were more susceptible to oxidative stress and oxidative damage than adults, especially very young cubs in the spring, when they also exhibited lower antioxidant biomarkers than adults. Although previous studies have found that intermediate spring and summer rainfall and warmer temperatures favor cub survival, counterintuitively these conditions were associated with more severe oxidative damage. Oxidative damage was high in cubs even when antioxidant biomarkers were high. In contrast, adult responses accorded with previous survival analyses. Wetter spring and summer conditions were associated with higher oxidative damage, but they were also associated with higher antioxidant biomarkers. Autumnal weather did not vary substantially from normative values, and thus effects were muted. Winter carryover effects were partially evident, with drier and milder conditions associated with greater oxidative damage in the following spring but also with higher antioxidant capacity. Plausibly, warmer conditions promoted more Badger activity, with associated metabolic costs at a time of year when food supply is limited. Modeling biomarkers against projected climate change scenarios predicted greater future risks of oxidative damage, although not necessarily exceeding antioxidant capacity. This interdisciplinary approach demonstrates that individual adaptive physiological responses are associated with variation in natural environmental conditions.
Christina D Buesching - One of the best experts on this subject based on the ideXlab platform.
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A non-invasive method to assess the reproductive status of the European Badger (Meles meles) from urinary sex-steroid metabolites
General and comparative endocrinology, 2020Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Martin Dehnhard, Christina D BueschingAbstract:Abstract Due to their unique reproductive physiology and behaviour, European Badgers (Meles meles) are often used as a model to study mammalian reproduction. For reproductive endocrinology, circulating hormone levels are conventionally measured directly from blood samples. However, routine blood sampling is often not practical for wild animals and may induce stress affecting measurement accuracy. Non-invasive alternatives are thus of interest. Circulating hormones are metabolized through different routes, either by the kidneys, to be excreted through urine, or by the liver, to be excreted through faeces. These metabolites can thus be used as a proxy of hormone measurements, provided the species-specific metabolic characteristics are known. Here we tested the suitability of measuring urinary metabolites of circulating plasma sex-steroid hormones (testosterone in males and oestrogen in females) with enzyme immunoassays to assess the reproductive status of the European Badger (Meles meles). Biological validation evidenced that urinary testosterone metabolite (UTM) and urinary total oestrogen metabolite (UEM) excretion patterns both corresponded with seasonal Badger reproductive patterns on a population level, signaling correlation over a broad time frame. On an individual level, concurrent sampling of urine and plasma showed that male plasma testosterone and UTM levels correlated significantly across seasons, but no short term correlation was evident for total oestrogen and UEM in females. Thus, in Badgers, urinary sex-steroid metabolites can be used reliably in the short term to assess male reproductive status at the individual level, but only at the broader population level for females.
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reproductive and somatic senescence in the European Badger meles meles evidence from lifetime sex steroid profiles
Zoology, 2020Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Abstract Among the Carnivora, there is sparse evidence for any substantive fitness benefits of post reproductive lifespan (PRLS, survival after reproductive cessation, RC). Using the European Badger (Meles meles) as a model species, we analyzed sex-specific cross-sectional endocrinological and morphological data to investigate: 1) age-dependent reproductive decline in sex-steroid levels versus prime reproductive age; 2) age-dependent declines in somatic condition and reproductive advertisement (from subcaudal scent gland secretion); 3) changes in reproductive success with age due to somatic and endocrinological decline; 4) occurrence of RC, PRLS, and post reproductive representation (PrR) in the population with reference to pre-pubescent hormone levels and evidenced by fewer cub assignments from pedigree. We provide strong evidence for a gradual, not abrupt, decline in sex-steroid levels with age, with both sexes following a concave (down) quadratic trend. For both sexes, the onset of decline in somatic condition commenced at the age of 3 years. In contrast, decline in reproductive hormones started at age ca. 5.5 years in females and 6 years in males, with similar rates of decline thereafter. Subcaudal gland secretion volume also decreased in both sexes, especially after age 5, suggesting less investment in reproductive advertisement. After age 3, fewer (surviving) females were assigned cubs. This coincided with the onset of somatic decline but came earlier than hormonal decline (5.5 years onwards). The decrease in offspring assignments commenced later in males at age 5-6 years; concomitant with onset of testosterone decline at 6 years. This suggests that, contrary to females, in males declining body condition does not preclude reproductive success (no ‘restraint’) in advance of hormonal senescence (‘constraint’). There was evidence of female PRLS, with very old adults living up to 2.59 ± 1.29 years after RC; although in males this evidence was weaker. We discuss the implications of these findings for RC and PRLS in the context of adaptive and non-adaptive hypotheses. There was evidence of over 2 years of Post Reproductive Life Span in both sexes.
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Male European Badger churrs: insights into call function and motivational basis
Mammalian Biology, 2020Co-Authors: Benjamin D. Charlton, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Determining the contexts of emission and information content of vocal signals can yield insights into the function of different call types, and remains an important step towards understanding the diversification of mammalian vocal repertoires. In this study, we used infra-red video cameras and remote audio recorders to document seasonal and contextual variation in male European Badger ( Meles meles ) churr production over a 24-month period, and acoustic analysis based on source-filter theory to examine whether churr acoustic structure varies according to the caller’s arousal state and identity. Our behavioural observations revealed that male churrs are produced almost exclusively during the breeding season. Further contextual analysis showed that males emit churrs during close-range interactions with female conspecifics, often during copulation attempts, and churr directly into sett entrances. In addition, males involved in close-range social interactions delivered churrs with more call units per second than those vocalising without other conspecifics in close proximity. Discriminant function analysis also revealed that male churrs are individually distinctive, and confirmed that the formants (vocal tract resonances) contribute the most to caller identity. These findings indicate that Badger churrs are sexual calls with the potential to signal male arousal state and identity in reproductive contexts. They also add to an increasing body of literature on the importance of formants for identity cueing in nonhuman mammals.
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heterochrony of puberty in the European Badger meles meles can be explained by growth rate and group size evidence for two endocrinological phenotypes
PLOS ONE, 2019Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Puberty is a key stage in mammalian ontogeny, involving endocrinological, physiological and behavioural changes, moderated by intrinsic and extrinsic factors. Thus, not all individuals within one population achieve sexual maturity simultaneously. Here, using the European Badger (Meles meles) as a model, we describe male testosterone and female oestrone profiles (using Enzyme-immunoassays) from first capture (3 months, post-weaning) until 28 months (attaining sexual maturity and final body size), along with metrics of somatic growth, scent gland development and maturation of external reproductive organs as well as intra-specific competition. In both sexes, endocrinological puberty commenced at ca. 11 months. Thereafter, cub hormone levels followed adult seasonal hormone patterns but at lower levels, with the majority of cubs reaching sexual maturity during their second mating season (22-28 months). Interestingly, there was evidence for two endocrinological phenotypes among male cubs (less evident in females), with early developers reaching sexual maturity at 11 months (first mating season) and late developers reaching sexual maturity at 22-26 months (second mating season). Early developers also attained a greater proportion of their ultimate adult size by 11 months, exhibiting faster growth rates than late developers (despite having similar adult size). Male cubs born into larger social groups tended to follow the late developer phenotype. Our results support the hypothesis that a minimum body size is required to reach sexual maturity, which may be achieved at different ages, even within a single population, where early maturity can confer individual fitness advantages and enhance population growth rate.
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effects of weather conditions on oxidative stress oxidative damage and antioxidant capacity in a wild living mammal the European Badger meles meles
Physiological and Biochemical Zoology, 2018Co-Authors: Kirstin Bilham, Christina D Buesching, Chris Newman, Michael J Noonan, Amy Boyd, Adrian Smith, David W MacdonaldAbstract:Wild-living animals are subject to weather variability that may cause the generation of reactive oxygen species, resulting in oxidative stress and tissue damage, potentially driving demographic responses. Our 3-yr field study investigated the effects of seasonal weather conditions on biomarkers for oxidative stress, oxidative damage, and antioxidant defense in the European Badger (Meles meles). We found age class effects: cubs were more susceptible to oxidative stress and oxidative damage than adults, especially very young cubs in the spring, when they also exhibited lower antioxidant biomarkers than adults. Although previous studies have found that intermediate spring and summer rainfall and warmer temperatures favor cub survival, counterintuitively these conditions were associated with more severe oxidative damage. Oxidative damage was high in cubs even when antioxidant biomarkers were high. In contrast, adult responses accorded with previous survival analyses. Wetter spring and summer conditions were associated with higher oxidative damage, but they were also associated with higher antioxidant biomarkers. Autumnal weather did not vary substantially from normative values, and thus effects were muted. Winter carryover effects were partially evident, with drier and milder conditions associated with greater oxidative damage in the following spring but also with higher antioxidant capacity. Plausibly, warmer conditions promoted more Badger activity, with associated metabolic costs at a time of year when food supply is limited. Modeling biomarkers against projected climate change scenarios predicted greater future risks of oxidative damage, although not necessarily exceeding antioxidant capacity. This interdisciplinary approach demonstrates that individual adaptive physiological responses are associated with variation in natural environmental conditions.
Hannah L Dugdale - One of the best experts on this subject based on the ideXlab platform.
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neighbouring group composition and within group relatedness drive extra group paternity rate in the European Badger meles meles
Journal of Evolutionary Biology, 2014Co-Authors: Christina D Buesching, Chris Newman, Hannah L Dugdale, Geetha Annavi, Terry Burke, David W MacdonaldAbstract:Extra-group paternity (EGP) occurs commonly among group-living mammals and plays an important role in mating systems and the dynamics of sexual selection; however, socio-ecological and genetic correlates of EGP have been underexplored. We use 23 years of demographic and genetic data from a high-density European Badger (Meles meles) population, to investigate the relationship between the rate of EGP in litters and mate availability, mate incompatibility and mate quality (heterozygosity). Relatedness between within-group assigned mothers and candidate fathers had a negative quadratic effect on EGP, whereas the number of neighbouring-group candidate fathers had a linear positive effect. We detected no effect of mean or maximum heterozygosity of within-group candidate fathers on EGP. Consequently, EGP was associated primarily with mate availability, subject to within-group genetic effects, potentially to mitigate mate incompatibility and inbreeding. In Badgers, cryptic female choice, facilitated by superfecundation, superfoetation and delayed implantation, prevents males from monopolizing within-group females. This resonates with a meta-analysis in group-living mammals, which proposed that higher rates of EGP occur when within-group males cannot monopolize within-group females. In contrast to the positive meta-analytic association, however, we found that EGP associated negatively with the number of within-group assigned mothers and the number of within-group candidate fathers; potentially a strategy to counter within-group males committing infanticide. The relationship between the rate of EGP and socio-ecological or genetic factors can therefore be intricate, and the potential for cryptic female choice must be accounted for in comparative studies.
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evolution of mhc class i genes in the European Badger meles meles
Ecology and Evolution, 2012Co-Authors: Chris Newman, David W Macdonald, Hannah L Dugdale, Yung Wa Sin, Terry BurkeAbstract:The major histocompatibility complex (MHC) plays a central role in the adaptive immune system and provides a good model with which to understand the evolutionary processes underlying functional genes. Trans-species polymorphism and orthology are both commonly found in MHC genes; however, mammalian MHC class I genes tend to cluster by species. Concerted evolution has the potential to homogenize different loci, whereas birth-and-death evolution can lead to the loss of orthologs; both processes result in monophyletic groups within species. Studies investigating the evolution of MHC class I genes have been biased toward a few particular taxa and model species. We present the first study of MHC class I genes in a species from the superfamily Musteloidea. The European Badger (Meles meles) exhibits moderate variation in MHC class I sequences when compared to other carnivores. We identified seven putatively functional sequences and nine pseudogenes from genomic (gDNA) and complementary (cDNA) DNA, signifying at least two functional class I loci. We found evidence for separate evolutionary histories of the α1 and α2/α3 domains. In the α1 domain, several sequences from different species were more closely related to each other than to sequences from the same species, resembling orthology or trans-species polymorphism. Balancing selection and probable recombination maintain genetic diversity in the α1 domain, evidenced by the detection of positive selection and a recombination event. By comparison, two recombination breakpoints indicate that the α2/α3 domains have most likely undergone concerted evolution, where recombination has homogenized the α2/α3 domains between genes, leading to species-specific clusters of sequences. Our findings highlight the importance of analyzing MHC domains separately.
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MHC class II genes in the European Badger (Meles meles): characterization, patterns of variation, and transcription analysis
Immunogenetics, 2012Co-Authors: Hannah L Dugdale, Chris Newman, David W Macdonald, Terry BurkeAbstract:The major histocompatibility complex (MHC) comprises many genes, some of which are polymorphic with numerous alleles. Sequence variation among alleles is most pronounced in exon 2 of the class II genes, which encodes the α1 and β1 domains that form the antigen-binding site (ABS) for the presentation of peptides. The MHC thus plays an important role in pathogen defense. European Badgers ( Meles meles ) are a good species in which to study the MHC, as they harbor a variety of pathogens. We present the first characterization of MHC class II genes, isolated from genomic DNA (gDNA) and complementary DNA (cDNA), in the European Badger. Examination of seven individuals revealed four DRB , two DQB , two DQA , and two DRA putatively functional gDNA sequences. All of these sequences, except DRA , exhibited high variability in exon 2; DRB had the highest variability. The ABS codons demonstrated high variability, due potentially to balancing selection, while non-ABS codons had lower variability. Positively selected sites were detected in DRB and DQA . Phylogenetic analysis demonstrated trans -species polymorphism of class II genes. Comparison with cDNA from whole blood revealed that only DRB had a transcription pattern reflecting the alleles that were present in the gDNA, while the other three genes had disparities between gDNA and cDNA. Only one sequence was transcribed, even though two gDNA sequences were present, from each of both DQB and DRA . Our characterization of Badger MHC sequences forms a basis for further studies of MHC variability, mate choice, and pathogen resistance in this, and other, species.
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Characterisation of twenty-one European Badger (Meles meles) microsatellite loci facilitates the discrimination of second-order relatives
Conservation Genetics Resources, 2011Co-Authors: Geetha Annavi, Chris Newman, David W Macdonald, Hannah L Dugdale, Deborah A. Dawson, Gavin J. Horsburgh, Carolyn Greig, Terry BurkeAbstract:The European Badger (Meles meles) breeds plurally in lowland England and is important economically due to its link with bovine tuberculosis (Mycobacterium bovis) transmission. To understand disease transmission and facilitate effective management, it is vital to elucidate the social structure of Badger groups. To improve parentage assignment and the discrimination of relatives, we isolated and characterised 21 polymorphic microsatellite loci in 24 individuals from Wytham Woods, Oxfordshire, UK. These 21 loci increased the discrimination power between full-siblings and half-siblings from 71 to 88%, when added to the existing 31 loci. Similarly, the combined non-exclusion probability increased from 3.0 × 10−8 to 5.8 × 10−13. Newly isolated Mel-592 (FR745854) was X-linked, based on the genotypes of 48 known-sex individuals and will enhance the genetic sex-typing of Badgers.
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mouthing off about developmental stress individuality of palate marking in the European Badger and its relationship with juvenile parasitoses
Journal of Zoology, 2011Co-Authors: Pierre Nouvellet, Christina D Buesching, Chris Newman, Hannah L Dugdale, David W MacdonaldAbstract:Fluctuating asymmetry has become a common measure of developmental instability (the inability of individuals to buffer their development from environmental stresses). Here we investigate the symmetry of palatine marking (maculation) in the European Badger Meles meles, with regard to the developmental impacts of coccidial endo-parasites. We ask whether maculation is a selected trait, and estimate its heritability. We examine the potential utility of palatine marking as a diagnostic tool for individual identification, and examine its stability over time. The palatine maculations of Badger cubs with the highest intensity of endoparasitic infection were relatively more asymmetrical than those of their less severely infected contemporaries. This weak relationship persisted and strengthened into adulthood, indicating a lasting developmental relationship between physiological challenge and the symmetry of palatine melanin deposition. We did not detect selection for the pattern of maculation. Although size of the maculated area was heritable (h 2 = 0.72 � 0.19), its symmetry was not. There was, however, a positive relationship between pair-wise co-ancestry and spatial similarity of these markings. There are no methods currently available to specifically calculate the heritability of 2D traits. Our findings highlight the need to develop new theoretical techniques, potentially elaborating upon the analysis presented. Maculation showed a quadratic trend with age: up to 4 years of age the area of palatine maculation increased in size, but decreased in symmetry; thereafter, in older individuals, size decreased while symmetry increased. Furthermore, despite our evidence for extrinsic factors having some capacity to influence the pattern of maculation over time, these markings were sufficiently stable to facilitate the recognition of individuals in a restricted Badger population (o50 individuals). Such proxies for previous life-history events may provide indicators of the developmental stresses experienced by individuals or populations, informing our understanding of animal societies and the effectiveness of conservation measures.
Richard J. Delahay - One of the best experts on this subject based on the ideXlab platform.
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investigation into the genetic diversity in toll like receptors 2 and 4 in the European Badger meles meles
Research in Veterinary Science, 2018Co-Authors: Andrew M Whiteoak, Richard J. Delahay, Justin Ideozu, Hadil Alkathiry, Alexandra J Tomlinson, Sara Cowen, Elizabeth Mullineaux, Eamonn Gormley, Richard J Birtles, Zhaorong LunAbstract:Abstract The Toll-like receptor (TLR) genes are a conserved family of genes central to the innate immune response to pathogen infection. They encode receptor proteins, recognise pathogen associated molecular patterns (PAMPs) and trigger initial immune responses. In some host-pathogen systems, it is reported that genetic differences, such as single nucleotide polymorphisms (SNPs), associate with disease resistance or susceptibility. Little is known about TLR gene diversity in the European Badger (Meles meles). We collected DNA from UK Badgers, carried out PCR amplification of the Badger TLR2 gene and exon 3 of TLR4 and determined DNA sequences for individual Badgers for TLR2 (n = 61) and TLR4 exon 3 (n = 59). No polymorphism was observed in TLR4. Three TLR2 amino acid haplotype variants were found. Ninety five percent of Badgers were homozygous for one common haplotype (H1), the remaining three Badgers had genotypes H1/H3, H1/H2 and H2/H2. By broad comparison with other species, diversity in TLR genes in Badgers seems low. This could be due to a relatively localised sampling or inherent low genetic diversity. Further studies are required to assess the generality of the low observed diversity and the relevance to the immunological status of Badgers.
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Performance of a Noninvasive Test for Detecting Mycobacterium bovis Shedding in European Badger (Meles meles) Populations
Journal of clinical microbiology, 2015Co-Authors: Hayley C. King, Andrew R. J. Murphy, Phillip James, Emma R. Travis, David W. Porter, Jason Sawyer, Jennifer Cork, Richard J. Delahay, William H. Gaze, Orin CourtenayAbstract:The incidence of Mycobacterium bovis, the causative agent of bovine tuberculosis, in cattle herds in the United Kingdom is increasing, resulting in substantial economic losses. The European Badger (Meles meles) is implicated as a wildlife reservoir and is the subject of control measures aimed at reducing the incidence of infection in cattle populations. Understanding the epidemiology of M. bovis in Badger populations is essential for directing control interventions and understanding disease spread; however, accurate diagnosis in live animals is challenging and currently uses invasive methods. Here we present a noninvasive diagnostic procedure and sampling regimen using field sampling of latrines and detection of M. bovis with quantitative PCR tests, the results of which strongly correlate with the results of immunoassays in the field at the social group level. This method allows M. bovis infections in Badger populations to be monitored without trapping and provides additional information on the quantities of bacterial DNA shed. Therefore, our approach may provide valuable insights into the epidemiology of bovine tuberculosis in Badger populations and inform disease control interventions.
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Behaviour-time budget and functional habitat use of a free-ranging European Badger(Meles meles)
Animal Biotelemetry, 2015Co-Authors: David W Mcclune, Richard J. Delahay, Nikki J Marks, W Ian Montgomery, David M ScantleburyAbstract:Background The European Badger ( Meles meles ) is involved in the maintenance of bovine tuberculosis infection and onward spread to cattle. However, little is known about how transmission occurs. One possible route could be through direct contact between infected Badgers and cattle. It is also possible that indirect contact between cattle and infected Badger excretory products such as faeces or urine may occur either on pasture or within and around farm buildings. A better understanding of behaviour patterns in wild Badgers may help to develop biosecurity measures to minimise direct and indirect contact between Badgers and cattle. However, monitoring the behaviour of free-ranging Badgers can be logistically challenging and labour intensive due to their nocturnal and semi-fossorial nature. We trialled a GPS and tri-axial accelerometer-equipped collar on a free-ranging Badger to assess its potential value to elucidate behaviour-time budgets and functional habitat use. Results During the recording period between 16:00 and 08:00 on a single night, resting was the most commonly identified behaviour (67.4%) followed by walking (20.9%), snuffling (9.5%) and trotting (2.3%). When examining accelerometer data associated with each GPS fix and habitat type (occurring 2 min 30 s before and after), walking was the most common behaviour in woodland (40.3%) and arable habitats (53.8%), while snuffling was the most common behaviour in pasture (61.9%). Several nocturnal resting periods were also observed. The total distance travelled was 2.28 km. Conclusions In the present report, we demonstrate proof of principle in the application of a combined GPS and accelerometer device to collect detailed quantitative data on wild Badger behaviour. Behaviour-time budgets allow us to investigate how Badgers allocate energy to different activities and how this might change with disease status. Such information could be useful in the development of measures to reduce opportunities for onward transmission of bovine tuberculosis from Badgers to cattle.
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behaviour time budget and functional habitat use of a free ranging European Badger meles meles
Animal Biotelemetry, 2015Co-Authors: David W Mcclune, Richard J. Delahay, Nikki J Marks, Ian W Montgomery, David M ScantleburyAbstract:The European Badger (Meles meles) is involved in the maintenance of bovine tuberculosis infection and onward spread to cattle. However, little is known about how transmission occurs. One possible route could be through direct contact between infected Badgers and cattle. It is also possible that indirect contact between cattle and infected Badger excretory products such as faeces or urine may occur either on pasture or within and around farm buildings. A better understanding of behaviour patterns in wild Badgers may help to develop biosecurity measures to minimise direct and indirect contact between Badgers and cattle. However, monitoring the behaviour of free-ranging Badgers can be logistically challenging and labour intensive due to their nocturnal and semi-fossorial nature. We trialled a GPS and tri-axial accelerometer-equipped collar on a free-ranging Badger to assess its potential value to elucidate behaviour-time budgets and functional habitat use. During the recording period between 16:00 and 08:00 on a single night, resting was the most commonly identified behaviour (67.4%) followed by walking (20.9%), snuffling (9.5%) and trotting (2.3%). When examining accelerometer data associated with each GPS fix and habitat type (occurring 2 min 30 s before and after), walking was the most common behaviour in woodland (40.3%) and arable habitats (53.8%), while snuffling was the most common behaviour in pasture (61.9%). Several nocturnal resting periods were also observed. The total distance travelled was 2.28 km. In the present report, we demonstrate proof of principle in the application of a combined GPS and accelerometer device to collect detailed quantitative data on wild Badger behaviour. Behaviour-time budgets allow us to investigate how Badgers allocate energy to different activities and how this might change with disease status. Such information could be useful in the development of measures to reduce opportunities for onward transmission of bovine tuberculosis from Badgers to cattle.
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Individual foraging specialisation in a social mammal: the European Badger (Meles meles).
Oecologia, 2014Co-Authors: Andrew Robertson, Richard J. Delahay, Robbie A. Mcdonald, Simon Kelly, Stuart BearhopAbstract:Individual specialisation has been identified in an increasing number of animal species and populations. However, in some groups, such as terrestrial mammals, it is difficult to disentangle individual niche variation from spatial variation in resource availability. In the present study, we investigate individual variation in the foraging niche of the European Badger (Meles meles), a social carnivore that lives in a shared group territory, but forages predominantly alone. Using stable isotope analysis, we distinguish the extent to which foraging variation in Badgers is determined by social and spatial constraints and by individual differences within groups. We found a tendency for individual Badgers within groups to differ markedly and consistently in their isotope values, suggesting that individuals living with access to the same resources occupied distinctive foraging niches. Although sex had a significant effect on isotope values, substantial variation within groups occurred independently of age and sex. Individual differences were consistent over a period of several months and in some instances were highly consistent across the two years of the study, suggesting long-term individual foraging specialisations. Individual specialisation in foraging may, therefore, persist in populations of territorial species not solely as a result of spatial variation in resources, but also arising from individuals selecting differently from the same available resources. Although the exact cause of this behaviour is unknown, we suggest that specialisation may occur due to learning trade-offs which may limit individual niche widths. However, ecological factors at the group level, such as competition, may also influence the degree of specialisation.
