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Animal species living in highly seasonal environments developed different strategies to cope with the periodical drastic change of environmental conditions. Hibernating mammals survive the winter season by reducing their activity and metabolism, and by centring their activities during the favourable season. Thus, the demography of these species depends upon both hibernating and active periods. In this study, we explored the apparent survival of Alpine marmots monitored between 2007 and 2018 in the North-Western Italian Alps. We fit Cormack-Jolly-Seber (CJS) models to quantify changes in the apparent survival and capture probability of marmots, after the hibernation phase and at the end of the summer. Apparent survival after winter almost reached 100% and it was higher than post-summer survival. Moreover, while post-summer apparent survival remained almost stable over lifetime, with a slight increase with age, characterised however by wide confidence intervals, overwinter survival decreased with age, especially after 6 years of age. No temporal trends, nor changes between areas at different elevations, were found. We suggest that these results arise from a combination of climatic conditions, predation pressure and social dynamics, which is a pivotal feature of this species and cannot be ignored when considering population dynamics of Alpine marmots. This study provides evidence of a higher survival in the hibernating mammals of the Alpine ecosystem, the Alpine marmot, compared to the survival of individuals during the summer season, providing the first evidence of different seasonal survival in this species. High overwinter survival in Alpine marmot [ABSTRACT FROM AUTHOR]

Recent findings suggest that immune functions do not unidirectionally deteriorate with age but that a potentially adaptive remodeling, where functions of the immune system get downregulated while others get upregulated with age could also occur. Scarce in wild populations, longitudinal studies are yet necessary to properly understand the patterns and consequences of age variations of the immune system in the wild. Meanwhile, it is challenging to understand if the observed variations in immune parameters with age are due to changes at the within‐individual level or to selective (dis)appearance of individuals with peculiar immune phenotypes. Thanks to a long‐term and longitudinal monitoring of a wild Alpine marmot population, we aimed to understand within‐ and between‐individual variation in the immune phenotype with age, in order to improve our knowledge about the occurrence and the evolutionary consequences of such age variations in the wild. To do so, we recorded the age‐specific leukocyte concentration and leukocyte profile in repeatedly sampled dominant individuals. We then tested whether the potential changes with age were attributable to within‐individual variations and/or selective (dis)appearance. Finally, we investigated if the leukocyte concentration and profiles were correlated to the probability of death at a given age. The leukocyte concentration was stable with age, but the relative number of lymphocytes decreased, while the relative number of neutrophils increased, over the course of an individual's life. Moreover, between individuals of the same age, individuals with fewer lymphocytes but more neutrophils were more likely to die. Therefore, selective disappearance seems to play a role in the age variations of the immune parameters in this population. Further investigations linking age variations in immune phenotype to individual fitness are needed to understand whether remodeling of the immune system with age could or could not be adaptive. [ABSTRACT FROM AUTHOR]

Extrinsic and intrinsic factors may influence the activity budget of wild animals, resulting in a variation in the time spent in different activities among populations or individuals of the same species. In this study, we examined how extrinsic and intrinsic factors affect the behaviour of the alpine marmot (Marmota marmota), a hibernating social rodent inhabiting high-elevation prairies in the European Alps. We collected behavioural observations during scan sampling sessions on marked individuals at two study sites with different environmental characteristics. We used Bayesian hierarchical multinomial regression models to analyse the influence of both intrinsic (sex and age-dominance status) and extrinsic (environmental and climatic variables) factors on the above-ground activity budget. Marmots spent most of their time above ground foraging, and were more likely to forage when it was cloudy. Extrinsic factors such as the site, period of the season (June, July–August, and August–September), and time of the day were all related to the probability of engaging in vigilance behaviour, which reaches its peak in early morning and late afternoon and during July, the second period included in the study. Social behaviours, such as affiliative and agonistic behaviours, were associated mostly with sex and age-dominance status, and yearlings were the more affiliative individuals compared to other status. Overall, our results suggest that in alpine marmots, intrinsic factors mostly regulate agonistic and affiliative behaviours, while extrinsic factors, with the unexpected exception of temperature, affect the probabilities of engaging in all types of behavioural categories. [ABSTRACT FROM AUTHOR]

Abstract Recent findings suggest that immune functions do not unidirectionally deteriorate with age but that a potentially adaptive remodeling, where functions of the immune system get downregulated while others get upregulated with age could also occur. Scarce in wild populations, longitudinal studies are yet necessary to properly understand the patterns and consequences of age variations of the immune system in the wild. Meanwhile, it is challenging to understand if the observed variations in immune parameters with age are due to changes at the within‐individual level or to selective (dis)appearance of individuals with peculiar immune phenotypes. Thanks to a long‐term and longitudinal monitoring of a wild Alpine marmot population, we aimed to understand within‐ and between‐individual variation in the immune phenotype with age, in order to improve our knowledge about the occurrence and the evolutionary consequences of such age variations in the wild. To do so, we recorded the age‐specific leukocyte concentration and leukocyte profile in repeatedly sampled dominant individuals. We then tested whether the potential changes with age were attributable to within‐individual variations and/or selective (dis)appearance. Finally, we investigated if the leukocyte concentration and profiles were correlated to the probability of death at a given age. The leukocyte concentration was stable with age, but the relative number of lymphocytes decreased, while the relative number of neutrophils increased, over the course of an individual's life. Moreover, between individuals of the same age, individuals with fewer lymphocytes but more neutrophils were more likely to die. Therefore, selective disappearance seems to play a role in the age variations of the immune parameters in this population. Further investigations linking age variations in immune phenotype to individual fitness are needed to understand whether remodeling of the immune system with age could or could not be adaptive.

Age‐specific survival trajectories can vary significantly among wild populations. Identifying the environmental conditions associated with such variability is of primary importance to understand the dynamics of free‐ranging populations. In this study, we investigated survival variations among alpine marmot (Marmota marmota) families living in areas with opposite environmental characteristics: the typical habitat of the species (alpine meadow) and a marginal area bordering the forest. We used data collected during an 11‐year study in the Gran Paradiso National Park (Italy) and performed a Bayesian survival trajectory analysis on marked individuals. Furthermore, we investigated, at a territorial level, the relationships among demographic parameters and habitat variables by using a path analysis approach. Contrary to our expectations, for most of the marmot's lifespan, survival rate was higher in the marginal site closer to the forest and with lower visibility than in the alpine meadow site. Path analysis indicated that the number of families living close to each other negatively affected the stability of the dominant couple, which in turn affected both juvenile survival and reproduction. Given the lower number of neighboring families which inhabited the marginal site and the potentially different predation pressure by the most effective predator in the area (Aquila chrysaetos), our results suggest that species adapted to live in open habitats may benefit from living in a marginal habitat. This study highlights the importance of habitats bordering the forest in the conservation of alpine marmots. [ABSTRACT FROM AUTHOR]

Alpine marmots are thought to be herbivores but to be selective regarding food choice with focus on plant material rich in proteins and fatty acids. Carnivorism has been occasionally observed in Alpine marmots in captivity as well as in the wild but has been considered rare and opportunistic. Here we report additional cases from zoos and the wild which indicate that Alpine marmots not only readily accept meat as food but are also capable of actively preying on vertebrates. We speculate that the intake of protein and fatty acids from animal tissues, whenever occasions arise, may have a nutritional value and could thus be adaptive for Alpine marmots. [ABSTRACT FROM AUTHOR]

In an environment with limited resources, parents may trade‐off the number of offspring produced against offspring mass. To maximize fitness under unpredictable environments, females must not only maximize mean annual reproductive success but also minimize between‐year variation in reproductive success. Thus, preferred strategies of maternal allocation might be to maximize the mass of their offspring or to produce a number of offspring of variable body masses.Many social species have evolved in variable and unpredictable environments where only the social environment can be predicted. If mothers seem to alter their total reproductive allocation to offspring depending on their social environment, how the total expenditure is allocated between the different offspring is still unknown.Here, we analysed how climatic and social environments influence strategies of maternal allocation and how these strategies impact pup first‐year survival in a wild population of Alpine marmots monitored between 1990 and 2016.We found that females acted as income breeders using resources immediately available for reproduction. Our results showed that the proportion of maternal mass allocated to offspring varied mainly with litter size. However, how maternal allocation is shared between pups depended on climatic and social environments. In general, mothers tended to have litters of greater average mass and small variability in favourable social environments or when resources are abundant and lighter average pup mass but high variability in unfavourable social environments or when resources are scarce.This variable allocation could correspond to dynamic bet‐hedging such that mothers influence the variance of pup mass within the litter in response to poor current environmental conditions. Our analysis of first‐year survival showed that females should maximize the body mass of their young whatever the conditions will be because pups of higher mass have higher survival, regardless of environmental conditions. When resources are scarce, this strategy might not be achievable for all pups so that mothers produced variable pups. In large litters, this strategy increased first‐year survival.Because pup variability affects parental fitness, differential allocation between pups of the same litter could have large consequences on fitness and thus on reproductive strategies of social species. [ABSTRACT FROM AUTHOR]

Quantification of cortisol concentration in hair has become a promising conservation tool for non-invasive monitoring of "stress" in wild populations, yet this method needs to be carefully validated for each species. The goals of the study were:•Immunologically validate two methods (study 1 and 2 respectively) to extract and quantify cortisol in the hair of wild Alpine marmots.•Compare the amount of cortisol extracted from hair samples using two methods i.e. cut into fine pieces (study 1) and hair samples pulverized using a ball mill (study 2).•Determine the extent to which methods in study 2 could provide individual specific hair cortisol (HC) measures when samples were taken from the same body location. Within and between individual variations in HC levels were examined from multiple hair samples from 14 subjects in study 2. We evaluated if inter-individual variations in HC levels could be explained by sex and age.At least twice the amount of cortisol was obtained per g/hair when samples were pulverized in a ball mill prior to extraction compared to when cut into pieces. Our methods demonstrated intra-individual consistency in HC at a given time point: inter-individual variation in HC was three times larger than within individual variance. Sex and age did not impact HC levels., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier B.V.)

To reproduce, animals have to form pairs and large variations in the degree of mate switching are observed. Extrinsic and intrinsic factors can constrain individual's mate switching. Among intrinsic factors, genes involved in pair‐bonding, such as Avpr‐1a, receive increasing attention. The length of microsatellites present in the regulatory region of Avpr‐1a determines the neural densities and distributions of the vasopressin receptors known to impact pair‐bonding behaviours. For the first time, we investigated whether and how the genetic makeup at Avpr‐1a, an intrinsic factor, and the social context, an extrinsic factor, experienced by wild Alpine marmot (Marmota marmota) females affect the proportion of extra‐pair young. This proportion was positively correlated with the length of their Avpr‐1a regulatory region but only when the social constraints were relaxed, that is when mature male subordinates were present. When ignoring the interactive effect between the length of their Avpr‐1a regulatory region and the social constraints, the genetic makeup at Avpr‐1a was not associated with the proportion of extra‐pair young. Under natural conditions, the genetic regulation of pair‐bonding could be hidden by extrinsic factors constraining mate choice. [ABSTRACT FROM AUTHOR]

Sociality modulates life-history traits through changes in resource allocation to fitness-related traits. However, how social factors at different stages of the life cycle modulate senescence remains poorly understood. To address this question, we assessed the influence of social environment in both early life and adulthood on actuarial senescence in the Alpine marmot, a cooperative breeder. The influence of helpers on actuarial senescence strongly differed depending on when help was provided and on the sex of the dominant. Being helped when adult slowed down senescence in both sexes. However, the effect of the presence of helpers during the year of birth of a dominant was sex specific. Among dominants helped during adulthood, females born in the presence of helpers senesced slower, whereas males senesced faster. Among dominants without helpers during adulthood, females with helpers at birth senesced faster. Social environment modulates senescence but acts differently between sexes and life stages. [ABSTRACT FROM AUTHOR]

In cooperative breeders, reproductive skew is extreme and leads to intense intrasexual competition for access to reproduction in both sexes. Given that securing the dominant position is costly, dominant animals should direct their aggressiveness towards same-sex subordinates that are potential competitors. Chemical communication has been reported to be involved in intrasexual competition in several mammalian species, and odour may be used as a cue to identify potential competitors. We predicted that odour should inform on sexual maturity, sex and social status in cooperative breeders. We tested these predictions in the Alpine marmot, a cooperatively breeding species, in which anal gland secretions are involved in aggressive behaviour. We sampled anal gland scents from 154 individuals of differing sexual maturity status, sex and social status. We found that anal gland secretions may inform on sexual maturity. When focusing on adult individuals, we found that anal gland scent differed according to sex and social status. Our results support the hypothesis that anal gland scent could be involved in intrasexual competition in Alpine marmots by allowing dominant individuals to target their aggressiveness towards same-sex competitors (i.e. sexually mature subordinates), resulting in the reproductive suppression of subordinates. [ABSTRACT FROM AUTHOR]

Obtaining reliable information on animal abundance in mountainous landscapes is challenging. Highly heterogeneous habitats tend to reduce detection probabilities, and the three-dimensional, rugged nature of the terrain poses severe limits to the fulfilment of a number of assumptions underlying several statistical methods. In this study, we compared the performance of 4 methods to estimate population size of Alpine marmot (Marmota marmota), a highly social semifossorial rodent widely distributed on the European Alps. Between May and August 2015, in a study area within the Stelvio National Park (Italy), we conducted 8 sessions of capture-mark-recapture, 6 sessions of mark-resight from vantage points, 8 sessions of line distance sampling along 4 transects, and 2 sessions using double-observer methods from vantage points. The minimum number of animals alive, obtained during the mark-resight surveys, was n=54 individuals. Capture-mark-recapture models estimated a population size of n=56 individuals (95% CI=45-87); similar, but more precise estimates were obtained with the mark-resight approach (Bowden's estimator: n=62, 95% CI=54-71; Poisson log-normal estimator: n=62, 95% CI=55-69). Line transect distance sampling and double-observer methods were severely biased low (line transect distance sampling: n=24 individuals, 95% CI=19-31; independent double-observer: n=24, 95% CI=22-35; dependent doubleobserver: n=15, 95% CI=15-20). Our results suggest that the probabilistic approach based on marked individuals yielded fairly robust estimates of population size. The underestimates obtained using distance sampling and double-observer methods were likely due to the violation of some underlying assumptions. While the topography of the mountainous landscape makes it difficult to randomize the distribution of line transects, the burrowing behaviour of the species is likely to violate the assumption of perfect detection on the transect; in addition, the semifossorial habits of marmots lower their detection probabilities, thus hampering the performance of these methods. [ABSTRACT FROM AUTHOR]

Habitat Suitability Models (HSMs) are central tools in physical and environmental planning because they are able to predict potential distribution of species. In this study two spatial methods were compared to define the HSM for Marmota marmota L. in the Adamello Brenta Nature Park in the Italian central southern part of the Alps. The first model was based on Weighted Linear Combination (WLC), a nonparametric overlay procedure, the second one was a parametric method based on logistic regression algorithm. Data collected in two sample areas were used to build the models, while data recorded along linear transects evenly distributed throughout the study area were used for testing the model performance. The models were validated calculating the Area Under the Curve (AUC) of the Relative Operating Characteristics (ROC). The two models had similar performances, but the accuracy of the WLC model was slightly higher than the logistic model (AUC of 0.833 instead of 0.821). The habitat preferences of Marmota marmota L. were also investigated with Jacobs index and chi-square test and compared with other studies in different environments. The results demonstrated that the relative importance of environmental factors for Marmota marmota L. changes depending on local conditions. [ABSTRACT FROM AUTHOR]

Despite being identified an area that is poorly understood regarding the effects of climate change, behavioural responses to climatic variability are seldom explored. Climatic variability is likely to cause large inter-annual variation in the frequency of extra-pair litters produced, a widespread alternative mating tactic to help prevent, correct or minimize the negative consequences of sub-optimal mate choice. In this study, we investigated how climatic variability affects the inter-annual variation in the proportion of extra-pair litters in a wild population of Alpine marmots. During 22 years of monitoring, the annual proportion of extra-pair litters directly increased with the onset of earlier springs and indirectly with increased snow in winters. Snowier winters resulted in a higher proportion of families with sexually mature male subordinates and thus, created a social context within which extra-pair paternity was favoured. Earlier spring snowmelt could create this pattern by relaxing energetic, movement and time constraints. Further, deeper snow in winter could also contribute by increasing litter size and juvenile survival. Optimal mate choice is particularly relevant to generate adaptive genetic diversity. Understanding the influence of environmental conditions and the capacity of the individuals to cope with them is crucial within the context of rapid climate change. [ABSTRACT FROM AUTHOR]

Morphological changes following changes in species' distribution and phenology have been suggested to be the third universal response to global environmental change. Although structural size and body mass result from different genetic, physiological, and ecological mechanisms, they are used interchangeably in studies evaluating population responses to environmental change. Using a 22-year (1991-2013) dataset including 1768 individuals, we investigated the coupled dynamics of size and mass in a hibernating mammal, the Alpine marmot ( Marmota marmota), in response to local environmental conditions. We (i) quantified temporal trends in both traits, (ii) determined the environmental drivers of trait dynamics, and (iii) identified the life-history processes underlying the observed changes. Both phenotypic traits were followed through life: we focused on the initial trait value (juvenile size and mass) and later-life development (annual change in size [Δsize] and mass [Δmass]). First, we demonstrated contrasting dynamics between size and mass over the study period. Juvenile size and subsequent Δsize showed significant declines, whereas juvenile mass and subsequent Δmass remained constant. As a consequence of smaller size associated with a similar mass, individuals were in better condition in recent years. Second, size and mass showed different sensitivities to environmental variables. Both traits benefited from early access to resources in spring, whereas Δmass, particularly in early life, also responded to summer and winter conditions. Third, the interannual variation in both traits was caused by changes in early life development. Our study supports the importance of considering the differences between size and mass responses to the environment when evaluating the mechanisms underlying population dynamics. The current practice of focusing on only one trait in population modeling can lead to misleading conclusions when evaluating species' resilience to contemporary climate change. [ABSTRACT FROM AUTHOR]

Reintroductions inherently involve a small number of founders leading reintroduced populations to be prone to genetic drift and, consequently, to inbreeding depression. Assessing the origins as the genetic diversity and structure of reintroduced populations compared to native populations are thus crucial to foresee their future. Here, we aim to clarify the origins of the Alpine marmots reintroduced in the Pyrenees and to evaluate the genetic consequences of this reintroduction after almost 30 years without monitoring. We search for the origins and compare the genetic structure and the genetic variability of three reintroduced Pyrenean and eight native Alpine populations using pairwise genetic distances, Bayesian clustering method and multivariate analyses. Our results reveal that the Alpine marmots reintroduced in the Pyrenees originated both from the Northern and the Southern Alps, and that, despite these multiple origins, none of the current Pyrenean marmots are admixed. The reintroduction led to a strong genetic differentiation and to a decrease in genetic diversity. This pattern likely results from the small number of founders and the low dispersal capacities of Alpine marmots and thus, highlight the necessity to consider both genetic characteristics and natural history when reintroducing a species. [ABSTRACT FROM AUTHOR]

Abstract: Sexual selection through female mate choice for genetic characteristics has been suggested to be an important evolutionary force maintaining genetic variation in animal populations. However, the genetic targets of female mate choice are not clearly identified and whether female mate choice is based on neutral genetic characteristics or on particular functional loci remains an open question. Here, we investigated the genetic targets of female mate choice in Alpine marmots (Marmota marmota), a socially monogamous mammal where extra‐pair paternity (EPP) occurs. We used 16 microsatellites to describe neutral genetic characteristics and two MHC loci belonging to MHC class I and II as functional genetic characteristics. Our results reveal that (1) neutral and MHC genetic characteristics convey different information in this species, (2) social pairs show a higher MHC class II dissimilarity than expected under random mate choice, and (3) the occurrence of EPP increases when social pairs present a high neutral genetic similarity or dissimilarity but also when they present low MHC class II dissimilarity. Thus, female mate choice is based on both neutral and MHC genetic characteristics, and the genetic characteristics targeted seem to be context dependent (i.e., the genes involved in social mate choice and genetic mate choice differ). We emphasize the need for empirical studies of mate choice in the wild using both neutral and MHC genetic characteristics because whether neutral and functional genetic characteristics convey similar information is not universal. [ABSTRACT FROM AUTHOR]

We investigated age-specific variation in survival of dominant individuals in a long-lived and monogamous mammal, the alpine marmot (Marmota marmota), from a large dataset collected during a 24-year intensive monitoring of a free-ranging population. We found evidence of actuarial senescence in dominant individuals for both sexes. Survivorship was constant with age until dominant marmots were between 6 and 8 years of age and declined markedly thereafter. No between sex differences occurred in the intensity of actuarial senescence, which might be related to the weak intensity of sexual selection in this socially monogamous mammal. More investigations are needed to know whether cooperative breeding, hibernation, and monogamy, which are key features of the alpine marmot life history, could have shaped the patterns of actuarial senescence we report. [ABSTRACT FROM AUTHOR]

In the context of global change, an increasing challenge is to understand the interaction between weather variables and life histories. Species-specific life histories should condition the way climate influences population dynamics, particularly those that are associated with environmental constraints, such as lifestyles like hibernation and sociality. However, the influence of lifestyle in the response of organisms to climate change remains poorly understood., Based on a 23-year longitudinal study on Alpine marmots, we investigated how their lifestyle, characterized by a long hibernation and a high degree of sociality, interacts with the ongoing climate change to shape temporal variation in age-specific survival., As generally reported in other hibernating species, we expected survival of Alpine marmots to be affected by the continuous lengthening of the growing season of plants more than by changes in winter conditions. We found, however, that Alpine marmots displayed lower juvenile survival over time. Colder winters associated with a thinner snow layer lowered juvenile survival, which in turn was associated with a decrease in the relative number of helpers in groups the following years, and therefore lowered the chances of over-winter survival of juveniles born in the most recent years., Our results provide evidence that constraints on life-history traits associated with hibernation and sociality caused juvenile survival to decrease over time, which might prevent Alpine marmots coping successfully with climate change. [ABSTRACT FROM AUTHOR]

Sociality should evolve when the fitness benefits of group living outweigh the costs. Theoretical models predict an optimal group size maximizing individual fitness. However, beyond the number of individuals present in a group, the characteristics of these individuals, like their sex, are likely to affect the fitness payoffs of group living. Using 20 years of individually based data on a social mammal, the Alpine marmot (Marmota marmota), we tested for the occurrence of an optimal group size and composition, and for sex-specific effects of group characteristics on fitness. Based on lifetime data of 52 males and 39 females, our findings support the existence of an optimal group size maximizing male fitness and an optimal group composition maximizing fitness of males and females. Additionally, although group characteristics (i.e., size, composition and instability) affecting male and female fitness differed, fitness depended strongly on the number of same-sex subordinates within the social group in the two sexes. By comparing multiple measures of social group characteristics and of fitness in both sexes, we highlighted the sex-specific determinants of fitness in the two sexes and revealed the crucial role of intrasexual competition in shaping social group composition. [ABSTRACT FROM AUTHOR]

In social species, the hierarchical status of an individual has important consequences for its fitness. While many studies have focused on individual condition to explain access to dominance, very few have investigated the influence of the social environment, especially during early life. Yet it is known that environmental conditions early in life may influence several traits at adulthood. Here, we examine the influence of early social environment on accession to dominance by investigating the influence of litter size and sex composition on survival and the probability of ascending to dominance later in life using a 20-year dataset from a wild population of Alpine marmots ( Marmota marmota). Although litter size had no effect on the fate of individuals, litter sex composition affected male juvenile survival and both male and female probabilities of reaching dominant status when adult. Male juveniles incur lower survival when the number of male juveniles in the litter increases, and individuals of both sexes from male-biased litters are more likely to become dominant than individuals from female-biased litters. However, the absolute number of sisters in the litter, rather than the sex ratio, seems to be an important predictor of the probability of acquiring dominant status: pups having more sisters are less likely to become dominant. Several potential mechanisms to explain these results are discussed. [ABSTRACT FROM AUTHOR]

In social mammals, territory size and shape vary according to the number and strength of neighbour individuals competing for resources. Two main theories have been proposed to explain this variability: the Group Augmentation (GA) and the realized Resource Holding Potential (rRHP) hypotheses. The first states that the outcome of the interactions among groups depends on the total number of individuals in the group while the second states that only the number of animals directly involved in intergroup competition determines this outcome. We collected data on space use of individually tagged Alpine marmots (Marmota marmota), a cooperative breeding species that overlaps part of its territory with neighbouring groups. In accordance with the rRHP hypothesis, we found that groups having higher proportion of helpers, rather than higher total number of individuals, had lower percentage of the territory overlapping with neighbouring groups and a larger area available for individual exclusive use. [ABSTRACT FROM AUTHOR]

The function of Alpine marmot subspecies burrows and factors influencing their distribution were investigated at 17 sites in the Tatra Mountains in Slovakia, Europe. Topographic variables and habitat types expected to influence the location of the Tatra marmot burrows were observed and examined. In the various locations of the studied home ranges (summer, winter and grazing areas, marmot trails) and outside the family territories, we recorded 36 vegetation samples including several reliefs. The collected data were analyzed using multivariate analysis. The summer areas of the marmot home ranges in the Tatra Mountains are often located within the alpine zone in communities of the Braun-Blanquet alliance Juncion trifidi (siliceous short stem grasslands) and in chionophilous communities on stable scree slopes of the alliance Festucion picturatae (tall stem grasslands). Marmots usually avoid habitats that have the lowest trophic benefits and the most extreme sites with low-stems or mat-grass communities in the alliance Nardion strictae, dense stands of dwarf pine in the alliance Pinion mugo (krummholz), and dwarf-shrub and lichen communities in the alliance Loiseleurio-Vaccinion. Marmot habitats in summer have suitable grazing areas. The most preferred habitats for foraging are grasslands and tall herb plant communities dominated by Calamagrostis villosa, Trisetum fuscum, and similar tall grass species. The most important factor influencing the locations of different parts of home ranges is the gradient of the relief structure. According to their functional differentiation, the location of a marmot burrow is most significantly influenced by the presence of convex geomorphic features and reinforced rock forms. [ABSTRACT FROM AUTHOR]

We investigated the influence of female age on five reproductive traits and on the offspring size-number trade-off from an extensive data set spanning 20 years of study on free-ranging Alpine marmots. Offspring mass increased with female age, whereas litter size and reproductive allocation remained constant in females up to 10 years of age and declined thereafter. Although reproductive allocation declined, post-weaning juvenile survival and the size-number trade-off did not change markedly throughout a female's lifetime. Senescence of annual reproductive success (i.e., the number of offspring surviving their first hibernation within a given litter) only resulted from senescence of litter size. The data were insufficient to determine whether the decrease in litter size with age was caused by declining litter size at birth, offspring pre-weaning survival, or both. Regardless, our findings demonstrate that marmot females display a size-number trade-off invariant with age, and that their reproductive tactic involves increasing offspring size at the cost of decreasing litter size with increasing age. As a result, reproductive performance remains constant throughout a female's lifetime, despite the deleterious effects of senescence in litter size. [ABSTRACT FROM AUTHOR]

The Alpine marmot (Marmota marmota) is a social mammal living in mountainous grassland areas and has the particularity to hibernate in winter. Recent studies on a population in the French Alps found that climate change is affecting Alpine marmot population dynamics and might impact their overall distribution in the future. Using Species Distribution Models (SDMs), the effect of climate change on Alpine marmot's future distribution was investigated at a local scale, in the western part of the Pyrenean massif (New-Aquitaine region, France). This scale was chosen as an appropriate action scale for the conservation strategy for the species. Three climatic scenarios were used (RCP 2.6, RCP 4.5, and RCP 8.5) over three future 30-year periods (2021–2050, 2040–2070, 2071–2100) to predict the short- to long-term potential distribution of the target species. The results are consistent with naturalistic knowledge of the species´ ecological needs in terms of variable importance and response type. Mean maximum temperature in winter, standard-deviation of daily temperature in winter, along with the median rainfall amount in summer were the three most important climatic variables. Predictions under the two most pessimistic climate scenarios showed potential large habitat loss. In the long term, for RCP 4.5, an estimated habitat loss of 18% was predicted. In the case of RCP 8.5, a higher impact was predicted, with a 54% habitat loss. Our results show that high impact due to climate change can be expected at a long term. In addition, if winter climatic conditions are important for marmot survival through hibernation, drought in summer might be one of the drivers of future population dynamic and distribution. Our findings can be applied for other species living in grassland mountainous environments and for which access to food resources in summer is essential, facilitating the conservation of target areas. • Species distribution model successfully predicted current regional marmots' distribution. • At a long-term scale (2070–2100), up to 54% marmot's habitat loss was due to climate change (RCP 8.5). • Winter temperature rise and summer drought increase impact marmot's future distribution. [ABSTRACT FROM AUTHOR]

Oribatid mites may be of epidemiological and medical importance because several species have been shown to serve as intermediate hosts for anoplocephalid tapeworms of wild and domestic animals. Despite their economic and conservation significance, relatively few studies examined factors influencing the effective number of oribatid mites that can serve as intermediate hosts. We examined variation in the structure of the edaphic arthropod community in functionally different territory parts of the Alpine marmot ( Marmota marmota latirostris), a known definitive host of a prevalent anoplocephalid tapeworm, Ctenotaenia marmotae. We used a field experiment to test whether the abundance of oribatid mites in marmot pastures is affected by the presence of fresh herbivore faeces. We found that the abundance of soil and litter dwelling oribatid mites in marmot pastures did not change shortly after faeces addition. In contrast, numbers of other predominant soil-litter and phoretic microarthropods increased after faeces addition. The abundance of the two predominant phoretic mites colonizing the faeces was inversely related to the abundance of oribatid mites. In contrast, the abundance of a ubiquitous soil-litter mesostigmatid mite was a positive function of oribatid numbers. Although absolute numbers of oribatid mites did not change after faeces addition, our study suggests that, depending on soil quality or type, the probability of tapeworm egg ingestion by oribatid mites can be reduced due to increased interspecific prey-predatory and trophic interactions. Latrine site selection in Alpine marmots is consistent with a reduced probability of tapeworm transmission by oribatids. [ABSTRACT FROM AUTHOR]

Although long neglected, female competition is widespread and may have stronger evolutionary consequences than previously thought. In singular breeders, reproductive success is conditional on social status, and intrasexual competition for the dominant position can be particularly severe in females. Because the ability of females to secure the dominant position may strongly influence their fitness, a better understanding of the determinants of dominance maintenance is needed. Using a 21-year data set on Alpine marmots, Marmota marmota, we investigated the potential drivers of female dominance loss in a singularly breeding mammal. Particularly, we tested whether the dominant females' ability to retain their social position depended on the number and the characteristics (age, relatedness to dominant individuals) of potential competitors in the social unit. To identify the potential underlying mechanism, we further investigated how the number of subordinate females affected females' competitive ability. We found that the risk of losing the dominant position increased with the number of subordinate adult females in the group, but that the age of the subordinate females and their parentage relationships to the dominant individuals were unlikely to be driving dominance loss in this species. Moreover, when the number of potential competitors in the social unit increased, we observed a difference in body mass increase between the dominant and her subordinates leading to a decrease in the body mass difference between dominant females and their subordinate adult females, and ultimately to a higher risk of females losing the dominant position. Overall, our results showed that the number of potential competitors in a social group affects the females' ability to secure their dominant position, and suggested that this effect is mediated through changes in female body mass. [ABSTRACT FROM AUTHOR]

Sex-specific senescence has been commonly reported in highly dimorphic and polygynous species. However, whether between-sex differences in senescence occur in monogamous and monomorphic species is poorly known. In this study, we used an extensive dataset of 20 years of mass measurements on free-ranging male and female Alpine marmots ( Marmota marmota), a medium-sized, long-lived, social and hibernating mammal, to assess sex-specific patterns of senescence in body mass. We tested for the occurrence of both a decrease in body mass scaled to absolute age (called chronological senescence) and a decrease in body mass scaled to individual age at death (called terminal decline). Whereas males showed evidence of both chronological senescence and terminal decline in body mass, females did not show any detectable senescence in body mass. This unexpected between-sex difference of senescence in a species subject to weak sexual selection might be shaped either by costs of an asymmetric intra-sex competition for mates or by costs of social thermoregulation. [ABSTRACT FROM AUTHOR]

The introduction of non-native species can pose environmental and economic risks, but under some conditions, introductions can serve conservation or recreational objectives. To minimize risks, introductions should be conducted following the International Union for Conservation of Nature's guidelines and should include an initial assessment and a follow-up., In 1948, to reduce the predation pressure on Pyrenean chamois Rupicapra pyrenaica pyrenaica by golden eagles Aquila chrysaetos, the alpine marmot Marmota marmota was introduced to the Pyrenees in Western Europe. In successive introductions, about 500 marmots were released, but the fate of the released animals and their impacts on the environment remain largely unstudied., The aim of this study was to assess the success of the introduction of the alpine marmot into the Pyrenees, 60 years after the initial release, and the potential impacts of this species on Pyrenean ecosystems., We reviewed what is known about the marmot populations introduced to the Pyrenees and other populations within their native range in the Alps, particularly in terms of population structure and dynamics, habitat use and potential environmental impacts., The alpine marmot is widely distributed and, apparently, well established in the Pyrenees. Population structure and demographic parameters are similar within and outside the historical distribution range of the species, and habitat suitability is one of the main reasons for the species' success in the Pyrenees. Few researchers have investigated the impacts of alpine marmots in the Pyrenees; thus, those impacts have to be inferred from those observed in the species' native range or in other species of marmot. Introduced alpine marmots are likely to impact on Pyrenean grasslands through grazing and burrowing, have the potential to alter Pyrenean food webs and could act as vectors of parasites and disease., Although the introduction of the alpine marmot in the Pyrenees appears to have been successful, more needs to be known about the effects of the established populations on the environment before informed management actions can be taken in the Pyrenees. [ABSTRACT FROM AUTHOR]

The way that plants and animals respond to climate change varies widely among species, but the biological features underlying their actual response remains largely unknown. Here, from a 20-year monitoring study, we document a continuous decrease in litter size of the Alpine marmot (Marmota marmota) since 1990. To cope with harsh winters, Alpine marmots hibernate in burrows and their reproductive output should depend more on spring conditions compared to animals that are active year-round. However, we show that litter size decreased over time because of the general thinning of winter snow cover that has been repeatedly reported to occur in the Alps over the same period, despite a positive effect of an earlier snowmelt in spring. Our results contrast markedly with a recent study on North American yellow-bellied marmots, suggesting that between-species differences in life histories can lead to opposite responses to climate change, even between closely related species. Our case study therefore demonstrates the idiosyncratic nature of the response to climate change and emphasizes, even for related species with similar ecological niches, that it may be hazardous to extrapolate life history responses to climate change from one species to another. [ABSTRACT FROM AUTHOR]

The major histocompatibility complex (MHC) genes code for proteins that play a critical role in the immune system response. The MHC genes are among the most polymorphic genes in vertebrates, presumably due to balancing selection. The two MHC classes appear to differ in the rate of evolution, but the reasons for this variation are not well understood. Here, we investigate the level of polymorphism and the evolution of sequences that code for the peptide-binding regions of MHC class I and class II DRB genes in the Alpine marmot ( Marmota marmota). We found evidence for four expressed MHC class I loci and two expressed MHC class II loci. MHC genes in marmots were characterized by low polymorphism, as one to eight alleles per putative locus were detected in 38 individuals from three French Alps populations. The generally limited degree of polymorphism, which was more pronounced in class I genes, is likely due to bottleneck the populations undergone. Additionally, gene duplication within each class might have compensated for the loss of polymorphism at particular loci. The two gene classes showed different patterns of evolution. The most polymorphic of the putative loci, Mama-DRB1, showed clear evidence of historical positive selection for amino acid replacements. However, no signal of positive selection was evident in the MHC class I genes. These contrasting patterns of sequence evolution may reflect differences in selection pressures acting on class I and class II genes. [ABSTRACT FROM AUTHOR]

Abstract: Archaeozoological investigations carried out at Grotta del Clusantin in the Italian north-eastern Alps suggest that this late Upper Palaeolithic site hosted small groups of marmot hunters. Taxonomic data describe an alpine grassland environment with arboreal and shrubby vegetation in proximity. The bone assemblage is extremely fragmented as a result of anthropic activities and post-depositional agents. The presence of percussion cones, butchering cutmarks, burnt bones, and the almost total absence of carnivore traces and animal lairs, suggests that humans are responsible for faunal accumulation. Experimental approaches on marmot specimens supported archaeological evidence, demonstrating elements of systematics and/or explaining anatomical absences. From field-evidence, lithic, and functional data, it has been inferred that this site was a specialized camp, used for exploiting and consuming several rodent carcasses, in the context of the first human occupations of the highlands at the onset of the LateGlacial interstadial. [Copyright &y& Elsevier]

Variation in how individuals cope behaviourally and physiologically with stressors is widespread and can have a significant impact on life-history traits and fitness, individual coping styles are characterised by differential behavioural and adrenocortical reactivity to various challenges. As stress hormones can affect the production of reactive chemical species and the antioxidant status, individuals with different coping styles may differ also in oxidative status. Field studies on wild mammalian populations are few in number and none so far has simultaneously tested the relationship between coping style, adrenocortical reactivity and oxidative status in the same individuals. We measured individual variation in coping styles along a proactive-reactive continuum together with variation in baseline and stress-induced plasma oxidative damage, plasma non-enzymatic antioxidant capacity and cortisol in wild alpine marmots, Marmota marmota. Confirmatory path analysis revealed that different coping styles are accompanied by different baseline and stress-induced plasma oxidative statuses. Our findings also highlight the potential role of cortisol as a mediator of such differences. [ABSTRACT FROM AUTHOR]

Three main hypotheses have been proposed to explain mate switching in monogamous species: the “better option” hypothesis, the incompatibility hypothesis, and the “forced divorce” hypothesis. We tested the predictions of these hypotheses for the first time in a monogamous mammal using long-term data from a natural population of Alpine marmots (Marmota marmota). Generally, pair disruption resulted in one of the pair members staying on the territory and re-pairing with a younger incomer, whereas the other disappeared from the territory. Replaced individuals were rarely found as dominant in a territory but were often injured or found dead. Individuals gained no benefit from mate switching: new mates were neither heavier, larger, or more heterozygote nor more genetically compatible than previous mates. Moreover, no increase in reproductive success was observed after re-pairing. The relationship between reproductive failure and occurrence of mate change was mainly due to infanticide by the incomer. Our results support the “forced divorce” hypothesis in the Alpine marmot and suggest that mate switching has strong consequences on breeding success. We discuss the importance of taking into account the cases of forced divorce while studying mate switching process and its evolutionary consequences in monogamous species. [ABSTRACT FROM PUBLISHER]

The project of marmot reintroduction in the Dolomiti Bellunesi National Park started in 2006. In May 2006 and May 2007, 80 ear-marked (by sex and family) marmots were released in two separate areas (20 ind./ year/area). In summer 2008 the populations produced 36 and 39 individuals, respectively; the animals born in the areas exceeded the number of released animals that survived. Only one pair bred successfully in the year of release; 87.5% of the surviving pairs bred the following year, including the pair breeding the previous year. We recorded the reproduction of a single female, and the acceptance of the litter by the male who later joined her. Mortality of the animals released in 2006 was 39% before the first winter and increased to 53.6% after the second summer. The first summer mortality of animals released in 2007 was higher, probably because of greater predation by golden eagles. The population density increased in late summer 2008 to 13.5 and 22.2 family units/100 ha, respectively in the two areas. In 2006, when both areas were uninhabited, the mean dispersion distance from the release site to settlement sites was greater in males than in females. Sixty-one per cent of the settlements consisted of pairs; 33%, a single male; and 6%, of a trio (marmots from different families). The single males settled more distantly than paired males. Of all the possible “same-family composed ” pairs, 77.6% occurred. [ABSTRACT FROM PUBLISHER]

Rock ptarmigan is a vulnerable species in the southern Pyrenees, with less than 300 pairs and two unconnected populations. Alpine marmot was introduced in the northern Pyrenees between 1955 and 1988, but they rapidly colonised the southern slopes, with an actual estimated population of around 10,000 individuals. Both species are mainly herbivores, develop their activities on the ground and have their offspring at the same time, so they may compete at various levels. We studied the possible interactions between the two species based on field observations, bibliographic data and Geographical Information System (GIS) analysis. We found that alpine marmot has colonised all habitats occupied by rock ptarmigan in the southern Pyrenees, but their plant diet is absolutely differentiated. We also analysed the composition of golden eagle nests and confirmed that this predator predates the two species. From field observations in areas where the two species have coexisted for more than 10 years, we observed no behavioural interaction between the two species. So, although both species share space and time in the alpine communities, both diet differentiation and probably behavioural avoidance permits their coexistence. [ABSTRACT FROM PUBLISHER]