The Experts below are selected from a list of 318 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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effects of mustelid gammaherpesvirus 1 musghv 1 reactivation in european badger Meles Meles genital tracts on reproductive fitness
Pathogenetics, 2020Co-Authors: Mingshan Tsai, Chris Newman, David W Macdonald, Andrew W. Byrne, Ursula Fogarty, James Okeeffe, Christina D BueschingAbstract:Reactivation of latent Gammaherpesvirus in the genital tract can lead to reproductive failure in domestic animals. Nevertheless, this pathophysiology has not received formal study in wild mammals. High prevalence of Mustelid gammaherpesvirus 1 (MusGHV-1) DNA detected in the genital tracts of European badgers (Meles Meles) implies that this common pathogen may be a sexual transmitted infection. Here we used PCR to test MusGHV-1 DNA prevalence in genital swabs collected from 144 wild badgers in Ireland (71 males, 73 females) to investigate impacts on male fertility indicators (sperm abundance and testes weight) and female fecundity (current reproductive output). MusGHV-1 reactivation had a negative effect on female reproduction, but not on male fertility; however males had a higher risk of MusGHV-1 reactivation than females, especially during the late-winter mating season, and genital MusGHV-1 reactivation differed between age classes, where 3–5 year old adults had significantly lower reactivation rates than younger or older ones. Negative results in foetal tissues from MusGHV-1 positive mothers indicated that cross-placental transmission was unlikely. This study has broader implications for how wide-spread gammaherpesvirus infections could affect reproductive performance in wild Carnivora species.
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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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extrinsic factors affecting cub development contribute to sexual size dimorphism in the european badger Meles Meles
Zoology, 2019Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Abstract Sexual size dimorphism (SSD) is common among mammals, with males typically being larger than females, as a product of sex-specific differences in growth rate and growth duration. The Musteloidea, however, exhibit a hypo-allometric reduction in SSD with increasing body size (contrary to Rensch’s rule). A variety of extrinsic factors can affect juvenile growth rates and end body size, where one sex may demonstrate greater vulnerability than the other towards a specific factor, moderating patterns and degrees of SSD. Here, we analyse how male and female European badgers (Meles Meles) differ in their somatic growth patterns. We compare the sex-specific growth curves across a range of somatic parameters and investigate what extrinsic (social and environmental) factors affect cub growth rates during the first 2 years of life leading to their sexual-dimorphic adult sizes. We found that average male final size of all measurements was significantly larger than those of females. Although male and female weanling cubs had similar body sizes, growth curves diverged significantly from ca. 11 months onwards due to continuous rapid growth of males versus slowing female growth. Consequently, females always concluded growth earlier than did males. In both sexes, extremities ceased to grow at an earlier age than did body length and zygomatic arch width. All badger cubs were impacted by their social environment as well as by weather conditions; however, male cubs were more sensitive to social factors, remaining smaller in social groups with more adult males present, whereas female final size was predominantly affected by weather and associated food availability. We discuss how extrinsic parameters can moderate patterns of SSD in the context of the differential equilibrium model.
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encoded information within urine influences behavioural responses among european badgers Meles Meles
2019Co-Authors: Tanesha M Allen, Chris Newman, David W Macdonald, Nadine Adrianna Sugianto, Charlotte Ryder, Christina D BueschingAbstract:Metabolic by-products like sex-steroid metabolites convey information regarding an individual’s physiological fitness and reproductive state. Urine and faeces containing these excreted metabolites can function as cues for conspecifics within social contexts, particularly for mate selection. Our pilot study investigated in scent provisioning experiments how donor- and responder-related characteristics influenced behavioural responses towards excreted sex-steroid metabolites. We used 51 urine samples with known urinary hormone concentrations (determined by EIA corrected for specific gravity) collected from known individuals in a high-density population of European badgers ( Meles Meles ) in Wytham Woods, Oxfordshire, UK during the spring mating season. Samples were provided in Eppendorf tubes pushed into the ground near badger setts to assess how response likelihood, sniff duration, and countermarking responses varied according to donor-related traits (age, sex, group familiarity and hormone concentrations). From 143 videos containing 26 identifiable adult responders, we observed adult badgers modifying their behaviour towards urine samples based on the perceived relevance to their own traits with badgers investigating and countermarking urine from opposite-sex donors more often than urine from same-sex donors. This suggests that urine-marking can serve as an adaptive signal for individual advertisement. Additionally, all badgers were more likely to investigate male urine (containing testosterone) than female urine (containing oestradiol); however, no other clear effects of sex-steroid metabolites were noticed. We consider that this could be a feature of the social evolution of badgers or arise because badgers signal reproductive status through other olfactory secretions, notably their unique subcaudal gland marking behaviour.
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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effects of mustelid gammaherpesvirus 1 musghv 1 reactivation in european badger Meles Meles genital tracts on reproductive fitness
Pathogenetics, 2020Co-Authors: Mingshan Tsai, Chris Newman, David W Macdonald, Andrew W. Byrne, Ursula Fogarty, James Okeeffe, Christina D BueschingAbstract:Reactivation of latent Gammaherpesvirus in the genital tract can lead to reproductive failure in domestic animals. Nevertheless, this pathophysiology has not received formal study in wild mammals. High prevalence of Mustelid gammaherpesvirus 1 (MusGHV-1) DNA detected in the genital tracts of European badgers (Meles Meles) implies that this common pathogen may be a sexual transmitted infection. Here we used PCR to test MusGHV-1 DNA prevalence in genital swabs collected from 144 wild badgers in Ireland (71 males, 73 females) to investigate impacts on male fertility indicators (sperm abundance and testes weight) and female fecundity (current reproductive output). MusGHV-1 reactivation had a negative effect on female reproduction, but not on male fertility; however males had a higher risk of MusGHV-1 reactivation than females, especially during the late-winter mating season, and genital MusGHV-1 reactivation differed between age classes, where 3–5 year old adults had significantly lower reactivation rates than younger or older ones. Negative results in foetal tissues from MusGHV-1 positive mothers indicated that cross-placental transmission was unlikely. This study has broader implications for how wide-spread gammaherpesvirus infections could affect reproductive performance in wild Carnivora species.
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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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extrinsic factors affecting cub development contribute to sexual size dimorphism in the european badger Meles Meles
Zoology, 2019Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Abstract Sexual size dimorphism (SSD) is common among mammals, with males typically being larger than females, as a product of sex-specific differences in growth rate and growth duration. The Musteloidea, however, exhibit a hypo-allometric reduction in SSD with increasing body size (contrary to Rensch’s rule). A variety of extrinsic factors can affect juvenile growth rates and end body size, where one sex may demonstrate greater vulnerability than the other towards a specific factor, moderating patterns and degrees of SSD. Here, we analyse how male and female European badgers (Meles Meles) differ in their somatic growth patterns. We compare the sex-specific growth curves across a range of somatic parameters and investigate what extrinsic (social and environmental) factors affect cub growth rates during the first 2 years of life leading to their sexual-dimorphic adult sizes. We found that average male final size of all measurements was significantly larger than those of females. Although male and female weanling cubs had similar body sizes, growth curves diverged significantly from ca. 11 months onwards due to continuous rapid growth of males versus slowing female growth. Consequently, females always concluded growth earlier than did males. In both sexes, extremities ceased to grow at an earlier age than did body length and zygomatic arch width. All badger cubs were impacted by their social environment as well as by weather conditions; however, male cubs were more sensitive to social factors, remaining smaller in social groups with more adult males present, whereas female final size was predominantly affected by weather and associated food availability. We discuss how extrinsic parameters can moderate patterns of SSD in the context of the differential equilibrium model.
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encoded information within urine influences behavioural responses among european badgers Meles Meles
2019Co-Authors: Tanesha M Allen, Chris Newman, David W Macdonald, Nadine Adrianna Sugianto, Charlotte Ryder, Christina D BueschingAbstract:Metabolic by-products like sex-steroid metabolites convey information regarding an individual’s physiological fitness and reproductive state. Urine and faeces containing these excreted metabolites can function as cues for conspecifics within social contexts, particularly for mate selection. Our pilot study investigated in scent provisioning experiments how donor- and responder-related characteristics influenced behavioural responses towards excreted sex-steroid metabolites. We used 51 urine samples with known urinary hormone concentrations (determined by EIA corrected for specific gravity) collected from known individuals in a high-density population of European badgers ( Meles Meles ) in Wytham Woods, Oxfordshire, UK during the spring mating season. Samples were provided in Eppendorf tubes pushed into the ground near badger setts to assess how response likelihood, sniff duration, and countermarking responses varied according to donor-related traits (age, sex, group familiarity and hormone concentrations). From 143 videos containing 26 identifiable adult responders, we observed adult badgers modifying their behaviour towards urine samples based on the perceived relevance to their own traits with badgers investigating and countermarking urine from opposite-sex donors more often than urine from same-sex donors. This suggests that urine-marking can serve as an adaptive signal for individual advertisement. Additionally, all badgers were more likely to investigate male urine (containing testosterone) than female urine (containing oestradiol); however, no other clear effects of sex-steroid metabolites were noticed. We consider that this could be a feature of the social evolution of badgers or arise because badgers signal reproductive status through other olfactory secretions, notably their unique subcaudal gland marking behaviour.
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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polygynandrous and repeated mounting behaviour in european badgers Meles Meles
Animal Behaviour, 2011Co-Authors: Amy Griffiths, Hannah L Dugdale, David W MacdonaldAbstract:Promiscuous and repeated mountings by females are evolutionarily intriguing as females are expected to be choosy and matings are expected to be costly. We evaluate the evolutionary basis of these behaviours in a high-density population of European badgers. We analysed postpartum mounting behaviour, in 3 years, at two neighbouring social groups each year. We demonstrate a polygynandrous social mating system, with repeated mounting. Mounting was skewed among females in four social-group-years, but overall did not differ from random, potentially because female reproductive success is context dependent, varying with local food availability and femaleefemale competition. Some males mounted more than others; however, male mounting frequency was not related to dominance rank, self-grooming rate, or body condition index. Mounting frequency did not predict paternity success; furthermore, a 16-year genetic data set showed that paternity success was positively correlated with body condition index. Females may therefore mount with males that do not father their offspring to minimize the risk of infanticide from them. Females may also trade mountings for allogrooming from males, but mounting frequency did not vary with relatedness, aggression received from males or sequential allomarking by males. We conclude that promiscuous and repeated mounting in badgers may have evolved to reduce maleemale aggression around mounting and the likelihood of infanticide from males by masking paternity. Promiscuous mounting of female badgers does not devalue the previous male’s sperm, but may promote sperm competition, genetic diversity and genetic compatibility.
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context dependent linear dominance hierarchies in social groups of european badgers Meles Meles
Animal Behaviour, 2009Co-Authors: Stacey E Hewitt, David W Macdonald, Hannah L DugdaleAbstract:A social hierarchy is generally assumed to exist in those mammalian societies in which the costs and benefits of group living are distributed unevenly among group members. We analysed infrared closed-circuit television footage, collected over 3 years in Wytham Woods, Oxfordshire, to test whether social groups of European badgers have dominance hierarchies. Analysis of directed aggression between dyads revealed linear dominance hierarchies in three social-group-years, but patterns within social groups were not consistent across years. Dominance hierarchies were significantly steeper than random in five out of six social-group-years. In those social-group-years where a linear hierarchy was determined, there was an effect of sex on dominance rank, with females gaining significantly higher rank than males in two social-group-years. Overall, rank was not related to age, nor did it appear to affect the likelihood of an individual being wounded, or an individual's breeding status. The latter resulted from nonorthogonality between sex and breeding status, as there were only two breeding males. Overall, hierarchies were primarily dominated by breeding females, and may occur when breeding competition arises. Relatedness, unreciprocated allogrooming and sequential allomarking were not consistently related to levels of directed aggression across social-group-years. We suggest that dominance structures within European badger groups may be context dependent, with future study required to complete our understanding of where, and when, they arise.
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reproductive skew and relatedness in social groups of european badgers Meles Meles
Molecular Ecology, 2008Co-Authors: Lisa C Pope, David W Macdonald, Hannah L Dugdale, Paul J. Johnson, Terry BurkeAbstract:Reproductive skew is a measure of the proportion of individuals of each sex that breed in a group and is a valuable measure for understanding the evolution and maintenance of sociality. Here, we provide the first quantification of reproductive skew within social groups of European badgers Meles Meles, throughout an 18-year study in a high-density population. We used 22 microsatellite loci to analyse within-group relatedness and demonstrated that badger groups contained relatives. The average within-group relatedness was high (R = 0.20) and approximately one-third of within-group dyads were more likely to represent first-order kin than unrelated pairs. Adult females within groups had higher pairwise relatedness than adult males, due to the high frequency of extra-group paternities, rather than permanent physical dispersal. Spatial clustering of relatives occurred among neighbouring groups, which we suggest was due to the majority of extra-group paternities being attributable to neighbouring males. Reproductive skew was found among within-group candidate fathers (B = 0.26) and candidate mothers (B = 0.07), but not among breeding individuals; our power to detect skew in the latter was low. We use these results to evaluate reproductive skew models. Although badger society best fits the assumptions of the incomplete-control models, our results were not consistent with their predictions. We suggest that this may be due to female control of paternity, female-female reproductive suppression occurring only in years with high food availability resulting in competition over access to breeding sites, extra-group paternity masking the benefits of natal philopatry, and/or the inconsistent occurrence of hierarchies that are linear when established.
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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effects of mustelid gammaherpesvirus 1 musghv 1 reactivation in european badger Meles Meles genital tracts on reproductive fitness
Pathogenetics, 2020Co-Authors: Mingshan Tsai, Chris Newman, David W Macdonald, Andrew W. Byrne, Ursula Fogarty, James Okeeffe, Christina D BueschingAbstract:Reactivation of latent Gammaherpesvirus in the genital tract can lead to reproductive failure in domestic animals. Nevertheless, this pathophysiology has not received formal study in wild mammals. High prevalence of Mustelid gammaherpesvirus 1 (MusGHV-1) DNA detected in the genital tracts of European badgers (Meles Meles) implies that this common pathogen may be a sexual transmitted infection. Here we used PCR to test MusGHV-1 DNA prevalence in genital swabs collected from 144 wild badgers in Ireland (71 males, 73 females) to investigate impacts on male fertility indicators (sperm abundance and testes weight) and female fecundity (current reproductive output). MusGHV-1 reactivation had a negative effect on female reproduction, but not on male fertility; however males had a higher risk of MusGHV-1 reactivation than females, especially during the late-winter mating season, and genital MusGHV-1 reactivation differed between age classes, where 3–5 year old adults had significantly lower reactivation rates than younger or older ones. Negative results in foetal tissues from MusGHV-1 positive mothers indicated that cross-placental transmission was unlikely. This study has broader implications for how wide-spread gammaherpesvirus infections could affect reproductive performance in wild Carnivora species.
-
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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extrinsic factors affecting cub development contribute to sexual size dimorphism in the european badger Meles Meles
Zoology, 2019Co-Authors: Nadine Adrianna Sugianto, David W Macdonald, Chris Newman, Christina D BueschingAbstract:Abstract Sexual size dimorphism (SSD) is common among mammals, with males typically being larger than females, as a product of sex-specific differences in growth rate and growth duration. The Musteloidea, however, exhibit a hypo-allometric reduction in SSD with increasing body size (contrary to Rensch’s rule). A variety of extrinsic factors can affect juvenile growth rates and end body size, where one sex may demonstrate greater vulnerability than the other towards a specific factor, moderating patterns and degrees of SSD. Here, we analyse how male and female European badgers (Meles Meles) differ in their somatic growth patterns. We compare the sex-specific growth curves across a range of somatic parameters and investigate what extrinsic (social and environmental) factors affect cub growth rates during the first 2 years of life leading to their sexual-dimorphic adult sizes. We found that average male final size of all measurements was significantly larger than those of females. Although male and female weanling cubs had similar body sizes, growth curves diverged significantly from ca. 11 months onwards due to continuous rapid growth of males versus slowing female growth. Consequently, females always concluded growth earlier than did males. In both sexes, extremities ceased to grow at an earlier age than did body length and zygomatic arch width. All badger cubs were impacted by their social environment as well as by weather conditions; however, male cubs were more sensitive to social factors, remaining smaller in social groups with more adult males present, whereas female final size was predominantly affected by weather and associated food availability. We discuss how extrinsic parameters can moderate patterns of SSD in the context of the differential equilibrium model.
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encoded information within urine influences behavioural responses among european badgers Meles Meles
2019Co-Authors: Tanesha M Allen, Chris Newman, David W Macdonald, Nadine Adrianna Sugianto, Charlotte Ryder, Christina D BueschingAbstract:Metabolic by-products like sex-steroid metabolites convey information regarding an individual’s physiological fitness and reproductive state. Urine and faeces containing these excreted metabolites can function as cues for conspecifics within social contexts, particularly for mate selection. Our pilot study investigated in scent provisioning experiments how donor- and responder-related characteristics influenced behavioural responses towards excreted sex-steroid metabolites. We used 51 urine samples with known urinary hormone concentrations (determined by EIA corrected for specific gravity) collected from known individuals in a high-density population of European badgers ( Meles Meles ) in Wytham Woods, Oxfordshire, UK during the spring mating season. Samples were provided in Eppendorf tubes pushed into the ground near badger setts to assess how response likelihood, sniff duration, and countermarking responses varied according to donor-related traits (age, sex, group familiarity and hormone concentrations). From 143 videos containing 26 identifiable adult responders, we observed adult badgers modifying their behaviour towards urine samples based on the perceived relevance to their own traits with badgers investigating and countermarking urine from opposite-sex donors more often than urine from same-sex donors. This suggests that urine-marking can serve as an adaptive signal for individual advertisement. Additionally, all badgers were more likely to investigate male urine (containing testosterone) than female urine (containing oestradiol); however, no other clear effects of sex-steroid metabolites were noticed. We consider that this could be a feature of the social evolution of badgers or arise because badgers signal reproductive status through other olfactory secretions, notably their unique subcaudal gland marking behaviour.
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ranging behaviour of badgers Meles Meles vaccinated with bacillus calmette guerin
Journal of Applied Ecology, 2017Co-Authors: Rosie Woodroffe, Christl A Donnelly, Cally Ham, Seth Y B Jackson, Kelly Moyes, Kayna Chapman, Naomi G Stratton, Samantha J CartwrightAbstract:Summary Because biological systems are complex, management interventions occasionally have unintended adverse consequences. For example, attempts to control bovine tuberculosis (TB) by culling badgers Meles Meles have, under some circumstances, inadvertently increased cattle TB risks. Such harmful effects occur because culling profoundly alters badger movement behaviour, increasing pathogen transmission both between badgers and from badgers to cattle. It has recently been suggested that another TB management tool, badger vaccination with Bacillus Calmette Guerin, might provoke similar behavioural changes and hence similar harmful effects for cattle. We therefore took advantage of an existing project, which monitored 54 GPS-collared badgers across four study sites in southwest Britain, to explore whether vaccination, or live trapping to administer vaccine, influenced badger movement behaviour. We detected no significant effects of either vaccination or trapping on badgers’ monthly home range size, nightly distance travelled, or frequency of trespassing in neighbouring territories. The estimated effect of vaccination on badger home range size [2% reduction, 95% confidence interval (CI) 18% reduction – 17% increase] was statistically non-significant, but significantly smaller than that associated with both widespread (180% increase, 95% CI 70–362% increase; P < 0·001) and localised badger culling (74% increase, 95% CI 4–191% increase; P = 0·038). Synthesis and applications. In contrast with culling, live trapping and vaccinating badgers did not measurably alter their movement behaviour, fuelling optimism that vaccination might contribute positively to cattle tuberculosis control. Our study illustrates how existing monitoring can be exploited to assess potentially adverse effects of wildlife management.
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social group size affects mycobacterium bovis infection in european badgers Meles Meles
Journal of Animal Ecology, 2009Co-Authors: Rosie Woodroffe, C L Cheeseman, Terry Burke, Christl A Donnelly, D R Cox, G Gettinby, Gao Wei, John F Bourne, Roger K Butlin, Peter GilksAbstract:1. In most social animals, the prevalence of directly transmitted pathogens increases in larger groups and at higher population densities. Such patterns are predicted by models of Mycobacterium bovis infection in European badgers (Meles Meles). 2. We investigated the relationship between badger abundance and M. bovis prevalence, using data on 2696 adult badgers in 10 populations sampled at the start of the Randomized Badger Culling Trial. 3. M. bovis prevalence was consistently higher at low badger densities and in small social groups. M. bovis prevalence was also higher among badgers whose genetic profiles suggested that they had immigrated into their assigned social groups. 4. The association between high M. bovis prevalence and small badger group size appeared not to have been caused by previous small-scale culling in study areas, which had been suspended, on average, 5 years before the start of the current study. 5. The observed pattern of prevalence might occur through badgers in smaller groups interacting more frequently with members of neighbouring groups; detailed behavioural data are needed to test this hypothesis. Likewise, longitudinal data are needed to determine whether the size of infected groups might be suppressed by disease-related mortality. 6. Although M. bovis prevalence was lower at high population densities, the absolute number of infected badgers was higher. However, this does not necessarily mean that the risk of M. bovis transmission to cattle is highest at high badger densities, since transmission risk depends on badger behaviour as well as on badger density.
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Costs of breeding status in the European badger Meles Meles
Journal of Zoology, 2009Co-Authors: Rosie Woodroffe, David W MacdonaldAbstract:Compared with other mammals, reproduction is expected to be particularly costly for European badgers (Meles Meles L.) since both the gestation and mating periods occur in the winter when the animals are inactive and feed little. This paper assesses the costs of breeding status in both male and female badgers, in terms of body condition, ectoparasite load, haematology and mortality. By the end of the lactation period (May), breeding females had suffered a marked loss in body condition, although there was no such cost associated with gestation. However, females regained the weight that they had lost by the autumn following lactation. Lactating two-year-olds experienced a higher age-specific mortality than those that did not breed, but there was no difference among older females. No costs of breeding status could be detected among males at the end of the spring mating period. However, breeding males sustained testicular activity later into the summer than non-breeders, and by the autumn they had acquired more bite wounds and become anaemic. This suggests that there was a physiological cost associated with extended testicular activity in breeding males.
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spatial association of mycobacterium bovis infection in cattle and badgers Meles Meles
Journal of Applied Ecology, 2005Co-Authors: Rosie Woodroffe, C L Cheeseman, R S Cliftonhadley, Christl A Donnelly, W T Johnston, F J Bourne, D R Cox, G Gettinby, R G Hewinson, A Le M FevreAbstract:1. Control of zoonotic disease is difficult to achieve when populations of multiple hosts, particularly wildlife, become persistently infected. Bovine tuberculosis (TB) is one such disease: its causative agent, Mycobacterium bovis, infects cattle, humans and multiple wildlife species including European badgers Meles Meles. 2. In Britain, from 1974 to 1998 various strategies for the control of cattle TB involved culling badgers in the immediate vicinity of TB-affected herds. However, patterns of association between cattle and badgers had not been investigated at a local scale. 3. Using data from the Randomized Badger Culling Trial, an ongoing large-scale study of TB dynamics and control, we investigated local geographical associations between M. bovis infection in badgers and cattle. 4. Mycobacterium bovis infections were locally clustered within both badger and cattle populations. 5. We show, for the first time, that M. bovis infections in badgers and cattle are spatially associated at a scale of 1-2 km. Badgers and cattle infected with the same strain type of M. bovis are particularly closely correlated. These observational data support the hypothesis that transmission occurs between the two host species; however, they cannot be used to evaluate the relative importance of badger-to-cattle and cattle-to-badger transmission. 6. Synthesis and applications. The close associations between M. bovis infections in cattle and badgers suggest that localized badger culling could reasonably be expected to reduce the risks of cattle TB infection; however, experimental culls have found no such beneficial effects over the time-scale on which they were tested. This demonstrates the difficulty of predicting the outcome of management interventions, and reinforces the need for well-designed empirical assessments of future control strategies.
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welfare of badgers Meles Meles subjected to culling patterns of trap related injury
Animal Welfare, 2005Co-Authors: Rosie Woodroffe, Christl A Donnelly, F J Bourne, D R Cox, G Gettinby, J P Mcinerney, W I MorrisonAbstract:For over 25 years, European badgers (Meles Meles) have been subject to culling in Britain in attempts to limit the spread of tuberculosis (TB) to cattle. As part of a far-reaching evaluation of the effectiveness and acceptability of badger culling as a TB control measure, this paper assesses one aspect of the welfare of badger populations subjected to culling: the risk of badgers confined to cage traps prior to despatch becoming injured as a result of rubbing or biting on the cage. In a large-scale field trial, 88% of badgers received no detectable injuries as a result of being confined in the trap. Of those that were injured, 72% received only minor skin abrasions. A minority (1.8% of the total) acquired damage to the teeth or jaws that may have caused serious pain. Although trap rounds were commenced in the early morning, badgers were no more likely to sustain injuries when they remained in traps until later in the day. Coating of cage traps, intended to give the wire mesh a smoother surface, was associated with a reduction in the incidence of minor skin abrasions, although it may have slightly increased the frequency of less common but more serious abrasions. Modification of the door design reduced tooth damage. Traps will be further modified if appropriate. However, all aspects of the conduct of trapping operations must balance badger welfare with concerns for the health and safety of field staff.