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International audience; Life histories are strongly age dependent, notably linked to the onset of reproductive maturity and subsequent senescence. Consequently, ageing is predicted to impact behaviour, through the expression of either mating tactics in males or neonatal antipredator tactics in females. However, the influence of ageing, and the associated reproductive activity, on spatial behaviour remains poorly investigated. In this regard, we quantified age- and sex-specific intra-annual variation in movement rates and space use of two large herbivores with contrasting life histories: the roe deer, Capreolus capreolus, an asocial species with a territorial male mating strategy and a hider neonatal tactic, and the Mediterranean mouflon, Ovis gmelini musimon × Ovis sp., a gregarious species with a roaming male mating strategy and a follower neonatal tactic. We expected age-related differences to be mostly related to (1) age-specific mating tactics during the rut for males and the presence/absence of offspring for females, and (2) experience and/or locomotory senescence otherwise. During the rutting period, older roe deer males travelled greater daily distances than younger males due to patrolling behaviours for territory defence, whereas older mouflon males travelled less than younger males, which often adopted coursing tactics to mate with females. During the birth period, reproductive females had smaller home ranges than nonreproductive females in roe deer, whereas no marked differences were observed in mouflon females. The most marked age-related variation in space use of mouflon occurred outside the reproductive periods; specifically, the oldest individuals travelled less far and had a smaller home range (females only) than younger individuals. Our findings illustrate how space use tactics vary within and between populations of large herbivores, providing strong evidence that age and reproductive activity are major determinants of their spatial behaviour. © 2020 The Association for the Study of Animal Behaviour

Little is known about whether female mating tactics vary with age based on their preference for mates. To fill this knowledge gap, we examined how maternal age is related to the age of their mates using detailed individual long-term monitoring of a genotyped and pedigreed European roe deer (Capreolus capreolus Linnaeus, 1758) population. We found that mating between old females and prime-aged males was more frequent than mating between prime-aged females and prime-aged males. This suggests that old females avoid old mates. Old females might be more selective in their mate choice than prime-aged females owing to increased mate-sampling effort. Our finding is in line with the terminal investment/allocation hypothesis. The study of age-related variation in female mating behaviour is particularly important because this behaviour can influence the intensity and direction of sexual selection and the maintenance of variation in male sexually selected traits. Further studies are needed to quantify the exact fitness benefits of age-specific mating tactics in females.

International audience; Assessing the evolutionary potential of animal populations in the wild is crucial to understanding how they may respond to selection mediated by rapid environmental change (e.g. habitat loss and fragmentation). A growing number of studies have investigated the adaptive role of behaviour, but assessments of its genetic basis in a natural setting remain scarce. We combined intensive biologging technology with genome‐wide data and a pedigree‐free quantitative genetic approach to quantify repeatability, heritability and evolvability for a suite of behaviours related to the risk avoidance‐resource acquisition trade‐off in a wild roe deer (Capreolus capreolus) population inhabiting a heterogeneous, human‐dominated landscape. These traits, linked to the stress response, movement and space‐use behaviour, were all moderately to highly repeatable. Furthermore, the repeatable among‐individual component of variation in these traits was partly due to additive genetic variance, with heritability estimates ranging from 0.21±0.08 to 0.70±0.11 and evolvability ranging from 1.1 to 4.3%. Changes in the trait mean can therefore occur under hypothetical directional selection over just a few generations. To the best of our knowledge, this is the first empirical demonstration of additive genetic variation in space‐use behaviour in a free‐ranging population based on genomic relatedness data. We conclude that wild animal populations may have the potential to adjust their spatial behaviour to human‐driven environmental modifications through micro‐evolutionary change.

International audience; Understanding how wild animals adapt to perturbations and their consequences for life history traits and population dynamics is a current focus of attention in ecology and conservation biology. Here, we analysed variation in the neutrophil to lymphocyte ratio (N:L ratio), a proxy of stress level, in wild roe deer Capreolus capreolus from three populations experiencing markedly different environmental conditions. We first assessed whether among-individual differences in the N:L ratio were consistent over time and across environmental contexts. We then investigated how both individual characteristics (behaviour at capture, age, sex, body mass), and environmental context (habitat and year quality) were linked to this indicator of stress level. We found moderate, but consistent, repeatability of the N:L ratio in all three populations, indicating stable among-individual differences in the way individuals cope physiologically with varying environmental conditions. In addition, we found a weak, but consistent, association between the N:L ratio and behaviour at capture in two of the three populations. Finally, the N:L ratio also varied in relation to temporal changes in environmental conditions. In particular, individuals had, on average, higher levels of stress in poor-quality years in two of the three populations. We discuss our results in relation to the coping styles framework. Significance statement Due to global change, natural populations are increasingly faced with unpredictable fluctuations of their environment. The stress response, via the release of glucocorticoids, is a key mechanism that enables individuals to cope with these variations. However, all individuals do not necessarily cope with life threatening and/or stressful situations in the same way, but as yet, the major drivers underlying variation in stress level remain unclear. We showed that the N:L ratio, reflecting baseline stress level, was repeatable and influenced by both individual and environmental factors. In particular, variation in the N:L ratio was linked to the quality of the year in terms of resource availability and, to a lesser extent, to the individual's behaviour at capture. Our study demonstrates that both environmental context and individual characteristics drive variation in the N:L ratio in a wild vertebrate population.

Toll-like Receptors (TLR) play a central role in recognition and host frontline defence against a wide range of pathogens. A number of recent studies have shown that TLR genes (Tlrs) often exhibit a large polymorphism in natural populations. Yet, there is little knowledge on how this polymorphism is maintained and how it influences disease susceptibility in the wild. In a previous work, we showed that someTlrsexhibit similarly high levels of genetic diversity thanMhcand contemporary signatures of balancing selection in roe deer (Capreolus capreolus), an abundant and widespread ungulate in Europe.Here, we tested whether Mhc-DrborTlr(Tlr2, Tlr4andTlr5) diversity is driven bypathogen-mediated selection. Weexamined the relationships between their genotype (heterozygosity status and presence of specific alleles) and infections withToxoplasmaandChlamydia, two intracellular pathogens known to cause reproductive failure in ungulates. We showed thatToxoplasmaandChlamydiaexposures vary significantly across year and landscape structure with few co-infection events detected, and that the two pathogens act antagonistically onTlr2polymorphism. By contrast, we found no evidence of association withMhc-Drband a limited support forTlrheterozygosity advantage. Our study confirmed the importance of looking beyondMhcgenes in wildlife immunogenetic studies. It also emphasized the necessity to consider multiple pathogen challenges and their spatiotemporal variation to improve our understanding of vertebrate defence evolution against pathogens.

Background Understanding the genetic and environmental mechanisms governing variation in morphology or phenology in wild populations is currently an important challenge. While there is a general consensus that selection is stronger under stressful conditions, it remains unclear whether the evolutionary potential of traits should increase or decrease with increasingly stressful conditions. Here, we investigate how contrasting environmental conditions during growth may affect the maternal and genetic components of body mass in roe deer, the most abundant and widespread wild ungulate in Western Europe. Body mass is a key life history trait that strongly influences both survival and reproductive performance in large herbivores. We used pedigrees and animal models to determine the variance components of juvenile and adult winter body mass in two populations experiencing contrasting early-life conditions. Results Our analyses showed that roe deer at Chizé, where habitat was poor and unpredictable, exhibited very low genetic variance in juvenile body mass. Instead, variance in mass was mainly driven by among-cohort differences in early-life conditions and maternal environment. In contrast, roe deer at Bogesund, where resource availability during the critical period of fawn rearing was higher, displayed a substantial level of genetic variance in body mass. We discuss the potential role of past demography and viability selection on fawn body mass on the erosion of genetic variance in the poor habitat. Conclusions Our study highlights the importance of accounting for both spatial (i.e. between-population variation) and temporal (i.e. cohort variation) heterogeneity in environmental conditions, especially in early life, to understand the potential for adaptive responses of wild populations to selection. Electronic supplementary material The online version of this article (10.1186/s12862-018-1154-9) contains supplementary material, which is available to authorized users.

An explanation for female multiple mating when males offer no material benefits but sperm remains elusive, largely because of a lack of empirical support for the genetic benefits hypothesis. We used 21 microsatellite markers to test for multiple paternities among 88 litters of roe deer, Capreolus capreolus, and to investigate the inbreeding avoidance hypothesis as a potential mechanism for the evolution of female multiple mating. From paternity analyses, we found that 13.5% of polytocous litters were sired by more than one male. We also found that a half-sib relationship was more likely than a full-sib relationship for 20.5% of all litters. This is the first report of multiple paternities in a territorial ungulate species. In support of the inbreeding avoidance hypothesis, we found that parents who were strongly related produced offspring with lower individual heterozygosity that survived less well during their first summer than fawns with unrelated parents. In addition, fawns from multiple paternity litters survived their first summer better than fawns from single paternity litters. However, it remains unclear whether all female multiple paternity events in this species are provoked by an initial consanguineous mating. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society 2009, 97, 128–139.

Natal dispersal is a three-phase process: the decision to leave the natal range, the search phase and finally the settlement phase. Not much is known about the search phase in large herbivores. We quantified the search behaviour of young roe deer from two contrasting populations, using different measures: search area, search rate, search intensity and philopatry of the search. A Principal Component Analysis showed that most measures were highly correlated. Comparing the first axis from this analysis between adult and young roe deer from the two different populations while controlling for habitat quality, we found that the young occupied a larger area, ranged on average farther away and performed more excursions than adults, regardless of their sex. These findings support the hypothesis that young roe deer explore their environment before definitively leaving their natal home range and settling in their adult range.

International audience; Dispersal is frequently more prevalent in one sex compared to the other. Greenwood proposed that patterns of sex-biased dispersal among birds and mammals are linked to their mating strategies. For species where males defend resources rather than females, he predicted female-biased dispersal, because males should remain at their birth site where they are familiar with the distribution of the resources that they must defend. Greenwood's hypothesis has been extensively supported among birds, where most species exhibit a resource-defence mating strategy. However, almost no equivalent information is available for mammals as males generally defend mates in this group. An exception is the European roe deer, a resource-defence mating ungulate. We thus tested Greenwood's hypothesis on this atypical mammalian model, looking for female-biased dispersal using sex-specific inter-individual genetic distances. We conclusively show that gene flow is not higher among females compared to males in the studied roe deer population, and hence that dispersal is not female-biased, suggesting that male mating strategy is not the primary selective force driving the evolution of dispersal in roe deer. We discuss the role of female mate choice and intra-sexual competition as possible alternative selective pressures involved

Behavioural consistency is a key assumption when evaluating how between-individual differences in behaviour influence life history tactics. Hence, understanding how and why variation in behavioural repeatability occurs is crucial. While analyses of behavioural repeatability are common, few studies of wild populations have investigated variation in repeatability in relation to individual status (e.g. sex, age, condition) and over different timescales. Here, we aimed to fill this gap by assessing within-population variation in the repeatability of docility, as assessed by the individual's response to human handling, in a free-ranging population of European roe deer, Capreolus capreolus. Docility was an equally repeatable behaviour at both short- and long-term timescales, suggesting that this behavioural trait is stable across time. Repeatability did not differ markedly between age and sex categories but tended to be higher in juvenile males than in juvenile females. Finally, contrary to expectation, individual variation in the repeatability of docility was not correlated with individual body mass. Further studies are required to assess the life history consequences of the individual variation in docility we report here. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

In temperate ungulates, the body weight of juveniles at the onset of winter is a crucial determinant of survival and can also influence subsequent reproductive success. However, growth may be retarded post-weaning, during winter, as a result of resource restriction and/or the demands of thermoregulation in harsh climatic conditions. Post-weaning growth rates of juveniles were compared in relation to varying density in two populations of roe deer Capreolus capreolus (Chize, Dourdan) monitored for 10 and 15 years, respectively. Body growth of fawns continued over the post-weaning stage of the juvenile period (October–March) at the rate of 0.017 kg/day at Chize and 0.014 kg/day at Dourdan. Deer density had no influence on this post-weaning growth rate of juveniles in their first winter. However, deer born in years of high density weighed less at a given date than those born in years of low density because of their smaller body size at the onset of winter, indicating density-dependent rates of growth before weaning. At Chize, the sexes grew at the same rate, but sexual dimorphism was apparent as males weighed about 1 kg (8%) more than females at a given date. At Dourdan, no significant sexual dimorphism was detected, although females tended to be heavier than males at a given date. We conclude that density influences juvenile body weight (through its effect on birth weight and/or post-natal growth rate) before weaning in this species and, despite continued growth after weaning, during winter, roe deer whose early growth is limited through interspecific competition cannot compensate for this early restriction.

1. The Marais Poitevin, one of the principal wintering and passage sites for ducks and waders in the East Atlantic flyway, underwent agricultural intensification in the 1980s. The numbers of ducks declined in the period 1979–96 in the main roost, Baie de l’Aiguillon; this was a site-specific phenomenon for which local factors were responsible. We describe here long-term changes in some key characteristics of the wetlands, paying particular attention to the principal factors affecting the quality of waterbird habitat: the area of semi-natural grasslands, water management and wildfowling. 2. The area of grasslands declined by 50% between 1970 and 1995, principally as a result of conversion to arable farmland. The pattern was observed over the whole area and was slightly more marked close to the day-roost of the ducks. The rate of change was greatest in the 1980s. Water levels, and therefore the flooded area, were reduced over the study period during the months of May to November. The numbers of wildfowlers declined from the 1970s, but the number of artificial wildfowling ponds increased, especially after 1980. The number of birds killed did not decline and may have increased. The quality of the ducks’ habitat therefore declined by all three measures. 3. Four species, mallard, shoveler, teal and gadwall, showed an increase in other sites in north and west France either over the whole period or over the last part (1984–96), while declining (shoveler and mallard) or remaining stable in the Baie de l’Aiguillon. Pintail remained stable in the other sites, while showing a long-term decline (over 30 years) in the Baie. Wigeon did not use the Baie in large numbers in the 1996 cold spell as they did until the 1980s. 4. The uncoupling of the trends for these species in the Baie from their trends in the other sites may reflect the loss of grassland feeding habitat in the Marais Poitevin. However, for mallard, pintail and shoveler the declines in the Baie were much stronger than the 50% loss of grasslands so other factors, such as the reduction in autumn flooding and/or shooting, are likely to have played a part. 5. Since the three measures of long-term trends in duck habitat co-varied it was not possible to separate their effects statistically. The hypotheses arising from this study need to be tested: this should be done using comparative and experimental approaches. Suggestions are made for the management of water levels and shooting in the feeding habitat close to the Baie de l’Aiguillon.

When individuals disperse, they modify the physical and social composition of their reproductive environment, potentially impacting their fitness. The choice an individual makes between dispersal and philopatry is thus critical, hence a better understanding of the mechanisms involved in the decision to leave the natal area is crucial. We explored how combinations of behavioural (exploration, mobility, activity and stress response) and morphological (body mass) traits measured prior to dispersal were linked to the subsequent dispersal decision in 77 roe deer Capreolus capreolus fawns. Using an unusually detailed multi-trait approach, we identified two independent behavioural continuums related to dispersal. First, a continuum of energetic expenditure contrasted individuals of low mobility, low variability in head activity and low body temperature with those that displayed opposite traits. Second, a continuum of neophobia contrasted individuals that explored more prior to dispersal and were more tolerant of capture with those that displayed opposite traits. While accounting for possible confounding effects of condition-dependence (body mass), we showed that future dispersers were less neophobic and had higher energetic budgets than future philopatric individuals, providing strong support for a dispersal syndrome in this species.

We estimated survival probabilities over a 9-year period for an introduced population of Mediterranean mouflon (Ovis gmelini), applying capture – recapture models to resighting data from individually marked animals. Survival was high and constant among lambs, yearling males, and adults of both sexes, and we were unable to detect senescence among old animals. Survival of female yearlings varied widely among years. No difference in survival probabilities between the sexes was detected, indicating that the survival costs of sexual selection were low in this dimorphic species. We suggest that these results may be explained by a lack of limiting conditions on this study site. An outbreak of keratoconjunctivitis during the rut of 1993 caused a marked fall in annual survival for both sexes. Among males, this decline was constant for all ages (approximately 23%), but for females the impact of the disease varied in relation to age, with young ewes particularly affected. Otherwise, the population appears to be stable and we hypothesise that the removal of animals for export and through hunting, together with stochastic events such as periodic epizootics, maintains mouflon numbers at a level where the influence of density-dependent resource limitation on survival is limited.

This paper examines the effects of increasing population density on the skeletal development of roe deer as indexed by variation in the size of the mandible. We tested for density-dependence in total jaw length and minimum diastema height among cohorts in a single, intensively studied population in France. A strong relationship of average adult jaw length of both males and females with deer density in the year of birth of a given cohort was observed, and presumably reflects inadequate nutrition of juveniles at high population density. No such relationship was observed for the minimum diastema height which remained constant over the range of densities studied. This relationship was exploited to investigate population trends of roe deer in Britain. In nine populations, where equivalent data were available for between 16 and 28 separate cohorts, a consistent pattern of variation in cohort jaw size was observed, with a decrease in average total length, but not diastema height, towards the present. This trend is discussed in relation to changes in habitat structure in the coniferous forests of Britain. The utility of cohort jaw length as a management tool to index population trends of roe deer is highlighted.

International audience; Natal dispersal (i.e. movements between the natal range of an individual and its first breeding site) is a complex process which can have profound impacts on population dynamics. In most species, only a proportion of juveniles actually disperse, but few empirical data are available on the factors that drive the decision to disperse. To understand the behavioural ontogeny of the decision to disperse, we investigated the ranging behaviour of 66 juvenile roe deer, Capreolus capreolus, monitored with GPS collars prior to and during the dispersal phase. We compared the number and features (distance and duration) of exploratory movements during the period prior to dispersal between philopatric individuals and dispersers. Overall, 76% of the juveniles that dispersed during their first spring performed exploratory movements prior to the dispersal period. Indeed, exploration prior to the dispersal phase was much more common among future dispersers than among future philopatric individuals, suggesting that dispersal of juveniles is facilitated to some degree by predispersal exploration forays. Furthermore, the direction of the dispersal event was correlated with the direction of previous exploration, although there was no relationship between exploration distance and subsequent dispersal distance. Thus, it appears that individuals that subsequently disperse first explore their environment, prior to definitively leaving their natal range, probably to obtain information on potential suitable adult ranges. Exploratory movements prior to dispersal can thus provide information that influences an individual's decision on whether or not to disperse and, if so, in which direction. (C) 2013 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

International audience; Most forests in Europe are patchily distributed within the agricultural landscape. Therefore, forest biogeochemistry in Europe cannot be understood without considering the connectivity of nutrient cycles between forest patches and fertilized cropland. In this paper, we quantified the role of roe deer, the most widespread wild ungulate in Europe, as a vector of nitrogen and phosphorus from fertilized fields to forest patches, in a typical agricultural landscape of southwestern Europe. We derived a model of nutrient transfer from a data set on deer density, landscape-use by individual deer, and nutrient content in feces. The model shows that the magnitude of nutrient transfer is highly sensitive to the proportion of forest patches within the landscape, and to the way deer use the landscape to feed and defecate. Hence, the magnitude of nutrient transfer varies substantially across the landscape. Locally, deer may significantly fertilize the forest, transferring the equivalent of almost 20% of the atmospheric deposition of nitrogen, and the equivalent of 0.13% of the total stock of phosphorus from cropland to forest patches each year. These inputs may markedly influence the biogeochemistry of forests in the long run, and the nitrogen to phosphorus ratio available to trees and forest plants. These results highlight the significant, but, heterogeneous, role of wild ungulates in forest biogeochemistry across Europe.

From a literature review of five wildlife ecology journals since 1937, we document how using indices to monitor ungulate body condition is common practice, with the kidney fat index (KFI = weight of fat around the kidneys/weight of kidneys without fat × 100) as the favoured tool (82% of studies). In this context, we highlight the problems of using indices when underlying statistical assumptions are not met (isometry, parallel slopes between treatments). We show, with real and simulated data for two cervids with contrasting fat storage strategies, how results from analysis of variance of KFI values differ from analysis of covariance (ANCOVA) of raw data. We conclude that the KFI is affected by the restrictions typically associated with derived index values, and as a consequence, statistical analysis of the KFI could generate spurious results leading to erroneous interpretations concerning variation in body condition of ungulate populations. Thus, we recommend analysing fat weight as an untransformed variable in ANCOVA (kidney weight as covariate) to describe body condition variation in ungulates.

Radiotracking of two roe deer Capreolus capreolus (1 female, 1 male) in a Mediterranean habitat (Matorrals) with a detailed analysis of the vegetation showed that within their annual home range the deers selected particular habitat types, according to the season. The northern slope was preferred by both animals. Comparatively to female, male had a larger annual home range (150 ha vs. 130 ha), composed of more widely scattered sites of preferred use in more seasonal vs variable habitat types. Habitat selection in different seasons was affected by several factors: i) in all seasons, abundance of Rubus ulmifolius and Rosa ssp., ii) strong winds, especially in winter, that caused the male to move to southern slope, iii) disturbance by hunting dogs in autumn that forced deers into one or two refuge zones, iv) aspect of deer biology, such as territory marking by the male and giving birth by the female, which modified not only behaviour but also use of space. Anecdotal evidence has suggested that, during the rutting period, female roe deer may undertake short excursions, outside of their normal home range, possibly to mate with a reproductive partner. To address this question, we analysed the ranging behaviour of 27 female roe deer Capreolus capreolus, equipped with GPS collars, inhabiting a fragmented landscape in France. We compared female movements during the rutting period with a non-rutting period over two summers using a recently published approach. Search intensity and home range size were significantly greater during the rutting period. The difference in home range size between the two periods was significantly greater in 2006 compared to 2005 and in open compared to closed habitat. We were not able to identify any influence of body mass on the difference in ranging behaviour between the two periods. Visual analysis of movement trajectories for 11 females revealed that 5 (45%) performed an excursion for a duration of a few hours to several days. We speculatively suggest that female rut excursions provide an opportunity for active mate choice in roe deer, where males are territorial, although we cannot rule out the alternative explanation that these movements are a means to avoid male harassment.

International audience; The effect of experimental manipulation of population density on home-range size was investigated in two free-ranging roe deer (Capreolus capreolus) populations under contrasting environmental conditions. In these two long-term monitoring studies, one in Bogesund, Sweden (12 years) and one in Dourdan, France (10 years), deer density varied fourfold through varying culling pressure. Home-range data were collected by radio-tracking across the periods of contrasting density of the studies. We predicted that home-range size for females should vary in relation to the level of feeding competition, while for males, competition for mating opportunities should also influence range size, at least in summer when roe bucks are territorial. We found a highly consistent pattern over the two populations, with strong effects of deer density on home-range size, as well as significant differences between winter and summer ranges and between the sexes. Home ranges were consistently smaller at high density compared to low density. Males had larger ranges than females and this was particularly so during summer. Lastly, winter ranges were generally larger than summer ranges, particularly among females, although males at Dourdan had larger summer ranges compared to winter ranges. We suggest that the reduction of range size at high deer density during winter, as well as summer, is linked to the solitary behaviour and territorial social system of roe deer, with possible effects of dominance rank, even outside the mating season

Cross-amplification permits transposition of microsatellite markers to closely related species. Multiplexing reduces time and cost further, exploiting simultaneous amplification of several primers. In cross-amplification tests of 55 ungulate primers in roe deer, 39 gave specific amplification products and 20 were polymorphic. Twelve primers were retained to form a multiplex kit. In 30 roe deer, average allelic diversity was 5.67 (range: 2-15), expected heterozygosity was 0.664 and mean polymorphic information content (PIC) value was 0.605. Probability of identity was P ID = 5 X 10-11 and probability of exclusion for parentage studies was P E1 = 0.98856 and P E2 = 0.99952. (Resume d'auteur)

The rate of wear of ruminant teeth may vary according to diet, habitat, and individual tooth characteristics. This variation may cause error in estimating the age of wild ungulates from patterns of tooth wear. We tested the ability of 10 observers to accurately estimate age from observation of tooth wear in a large sample of jaws of known-age roe deer (Capreolus capreolus) from three populations. Although the average error was not large (±1.02 years), maximum error ranged from -5 to +6 years for jaws of animals between 1 and 7 years old, with observers generally overestimating the age of young animals and underestimating the age of old animals. We found significant differences among observers in estimation error. When a "jaw-board" of known-age reference specimens was provided, this observer effect was largely controlled for, but accuracy was not improved. Error was partly due to variation in tooth wear, both within and among populations. Initial cusp height of the first molar was lower, but tooth wear tended to be slower in one population than in the other two populations, possibly reflecting differences in diet and (or) habitat. Individual variation in tooth wear within populations was observed, possibly reflecting variation in tooth characteristics (e.g., enamel mineralisation), which was a source of error in age estimation from observation. Observers tended to underestimate the age of jaws with a relatively low degree of wear and vice versa. These results show that estimating the age of roe deer from observation of tooth wear produces biased results, severely limiting its application in population studies of this species.

We studied the barking behaviour of free-ranging roe deer, Capreolus capreolus, in response to disturbance provoked by a human observer and in response to the playback of recorded barks. Three alternative functions of this behaviour were hypothesized: barking is an alarm call, a pursuit-deterrent call or a territorial call. Our observational data showed that, in the presence of a source of disturbance, solitary individuals barked more frequently than deer in groups, suggesting that barking does not serve to warn conspecifics of potential danger, but rather to inform any potential predator that it has been identified. The frequencies of both barking and counterbarking (barking of a second deer in response to the barks of an initiator) were inversely correlated with ambient luminosity, probably because the assessment of danger is more difficult when visibility is low. Males barked more frequently than females when disturbed. Moreover, when we played back a series of barks from within a buck's territory, this provoked counterbarking or aggressive behaviours rather than flight. Older bucks responded more frequently to playbacks than younger bucks. We suggest that while barking may initially have evolved as a signal to deter predator pursuit, it could play an important, secondary role in the territorial system of this species. Copyright 1999 The Association for the Study of Animal Behaviour.

We studied seasonal habitat use of female, mixed-sex and male groups in a free-ranging mouflon (Ovis gmelini) population. The three group types differed in the use of the five different habitats (forests, broom moorlands, heather moorlands, meadows and rocky areas) only in spring (lambing period) and in autumn (rutting period). To study habitat selection, we compared the proportion of groups observed in each habitat type with the proportion of each of these habitat types sampled. This revealed that, for the four seasons, all three group types selected certain habitats. Overall, mouflon selected meadows and/or broom moorlands, but male groups switched to forests in spring and autumn. We examined this pattern of habitat selection in relation to shelter value and feeding activity for the three group types. Wind strength played a role in determining patterns of habitat use during the climatic extremes of winter and summer. Male and female groups consistently fed in the same habitat types, even though they did not select the same habitats in spring and autumn and despite a marked segregation between the sexes in this population. Two commonly cited hypothesis for explaining sexual segregation based on sexual size dimorphism and on alternative reproductive strategies of males and females were not supported by our results. We suggest that simple behavioural mechanisms may suffice to explain sexual segregation in this population.

This paper investigates variation in female fecundity in relation to effects of age and body weight within and between 15 populations of roe deer Capreolus capreolus (Linnaeus, 1758) in Britain. Analyses were based on carcass material and fecundity was assessed from the presence/absence and number fertilised ovulations (corpora lutea) and implanted foetuses. A significant proportion (>10%) of does ovulated in their first year in some populations, but such precocious reproductive activity rarely resulted in successful implantation of a foetus.

Patterns of growth and seasonal variation in body mass, kidney fat level, and bone marrow fat level were investigated in a roe deer population south of Paris. Size dimorphism was not apparent until the deer were 2 years of age, following a second period of rapid growth in males during spring–summer. No differences between the sexes in fat accumulation or in the periodicity of the annual fat cycle were observed. However, annual cycles of adult body mass were asynchronous between the sexes. Carcase mass was stable for much of the year, but one marked seasonal decline was observed in animals of each sex. For females (April–August) this reflected investment in late gestation and lactation, but among males (April–November) it was presumably linked to the costs of rutting. Contrary to reports for other ungulates, no over-winter decline in adult carcase mass, kidney fat level, or bone marrow fat level was observed, possibly because winters were mild. All four fat indices (kidney fat index, three bone-marrow fat indices) declined over spring–summer. This seasonal cyclicity does not match the energy requirements of reproductive activity, suggesting that the fat cycle is intrinsic, linked to seasonal metabolic variation in roe deer. We suggest that carcase mass is a more reliable index of condition in roe deer.

In this paper, we present an analysis of the consequences of increasing density, over a period of nine years (from 1980 to 1988), on the dynamics, and the social and spatial organization of a forest roe deer population. Hunting of this population ceased in 1979, after which time there was a significant increase in population density, with three distinct periods easily identified: 1980–1983 (PI), immediately following cessation of hunting, characterized by a relatively low density (d = 5–7 animals/100 ha), 1984–1985 (P2), a period of rapid population growth, and 1986–88 (P3), a period of high density (d = 25 animals/100 ha). During PI, the population was irregularly distributed across the study site but, as density increased, distribution became more uniform, and eventually covered the whole of the available area. Home-range structure and shape remained unchanged from PI to P3 but, by the end of the study, average range size was 30% lower for adult males only, and the period prior to subadult males, but not females, establishing a permanent home range had increased from c. 18 month to c. 30 months. Winter group size increased overall from PI to P3 with, for the first time, observations of groups of five or more animals and a reduction in the frequency of observations of solitary females, with does more commonly observed in pairs or small groups; the proportion of solitary males, however, did not change between the two periods. The mean number of kids per female declined significantly from PI to P3 and body weights recorded for juveniles of both sexes and for adult males were also significantly lower during the period of relatively high density (P3). However, for adult females, absolutely no body weight change was observed. This divergence between the sexes of response to increasing density is discussed.