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In most species of vertebrates, teeth play a central role in the long-term performance of individuals. However, patterns of tooth development have been little investigated as an indicator of animal performance. We filled this gap using data collected during long-term capture-mark-recapture monitoring of 1152 roe deer fawns at Chize, western France. This population fluctuated greatly in size during the 27 years of monitoring, offering a unique opportunity to assess how the eruption patterns of front teeth perform as indicator of animal performance. We used three indices of the eruption of permanent front teeth, the simplest being whether or not incisor I2 has erupted, and the most complex being a 12-level factor distinguishing the different stages of tooth eruption. We also assessed the relevance of these indices as compared to fawn body mass, a widely used indicator of animal performance of deer populations. Dental indices and body mass were positively correlated (all r > 0.62). Similarly to body mass, all indices based on tooth eruption patterns responded to changes of population size and can be reliably used to assess the relationship between roe deer and their environment. We found a linear decrease in body mass with increasing population size (r2 = 0.54) and a simultaneous delay in tooth development (r2 = 0.48–0.55 from the least to the most accurate indicator). However, tooth development would be not further delayed in years with the highest densities (>15 adult roe deer/100 ha). A path analysis supported the population density effect on tooth eruption patterns being mainly determined by the effect of population size on body mass. Our study provides managers with simple indices (e.g., presence-absence of I2) that provide a technically more easy way to standardize measurements of deer density-dependent responses over large geographical and temporal scales than would be possible with body mass.

International audience; In seasonal environments, parturition of most vertebrates generally occurs within a short time-window each year. This synchrony is generally interpreted as being adaptive, as early born young survive better over the critical season than late born young. Among large herbivores, the factors involved in driving among- and within-individual variation in parturition date are poorly understood. We explored this question by analyzing the relative importance of attributes linked to female quality (longevity, median adult body mass and cohort), time-dependent attributes linked to female condition (reproductive success the previous year, relative annual body mass and offspring cohort (year)), and age in shaping observed variation in parturition date of roe deer. A measure of quality combining the effects of female longevity and median adult body mass accounted for 11% of the observed among-individual variation in parturition date. Females of 2 yr old give birth 5 d later than older females. Our study demonstrates that high quality (heavy and long-lived) females give birth earlier than low quality females. Temporally variable attributes linked to female condition, such as reproductive success in the previous year and relative annual body mass, had no detectable influence on parturition date. We conclude that parturition date, a crucial determinant of reproductive success, is shaped by attributes linked to female quality rather than by time-dependent attributes linked to female condition in income breeders (individuals that rely on current resource intake rather than on accumulated body reserves to offset the increased energy requirements due to reproduction) such as roe deer.

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; The timing of birth has marked impacts on early life and early development of newborns in many species. In seasonal environments, early-born offspring often survive and grow better than late-born offspring, but despite the long-lasting effects of early conditions on life history traits, the influence of birth date on fitness has rarely been investigated for long-lived species. In this study, we analyzed both the short-and long-term effects of birth date on individual life history traits and explored its subsequent impact on individual fitness in a population of roe deer. We considered both the direct effects, as well as the indirect effects of birth date mediated through the effects of body mass, on demographic parameters. We found that in addition to short-term effects on early body growth and survival, birth date generates "silver spoon'' effects on adult life history traits of female roe deer. Birth date had long-lasting effects on female adult body mass such that early-born females were, on average, 3 kg heavier as adults than late-born females, although female adult survival was similar between these categories. Based on the observed relationships between birth date, body mass, and demographic parameters, we built an integral projection model describing the simultaneous distributions of birth date and body mass to quantify the fitness consequences of birth date. We found that the fitness of early-born females was higher than that of late-born females. These long-lasting effects of birth date on fitness were mostly mediated through the influence of birth date on recruitment and adult body mass. By determining development of newborns during the early stages of life, birth date has a critical influence on each step of an individual's subsequent life history trajectory.

Summary 1. Demographic rates can vary not only with measured individual characters like age, sex and mass but also with unmeasured individual variables like behaviour, genes and health. 2. Predictions from population models that include measured individual characteristics often differ from models that exclude them. Similarly, unmeasured individual differences have the potential to impact predictions from population models. However, unmeasured individual differences are rarely included in population models. 3. We construct stage- and age-structured models (where stage is mass) of a roe deer population, which are parameterized from statistical functions that either include, or ignore, unmeasured individual differences. 4. We found that mass and age structures substantially impacted model parameters describing population dynamics, as did temporal environmental variation, while unmeasured individual differences impacted parameters describing population dynamics to a much smaller extent once individual heterogeneity related to mass and age has been included in the model. We discuss how our assumptions (unmeasured individual differences only in mean trait values) could have influenced our findings and under what circumstances unmeasured individual differences could have had a larger impact on population dynamics. 5. There are two reasons explaining the relative small influence of unmeasured individual differences on population dynamics in roe deer. First, individual body mass and age both capture a large amount of individual differences in roe deer. Second, in large populations of long-lived animals, the average quality of individuals (independent of age and mass) within the population is unlikely to show substantial variation over time, unless rapid evolution is occurring. So even though a population consisting of high-quality individuals would have much higher population growth rate than a population consisting of low-quality individuals, the probability of observing a population consisting only of high-quality individuals is small.

This paper reports evidence for family effects (i.e., nonindependence between siblings) on components of juvenile fitness in two high-performance populations of roe deer (Capreolus capreolus). In Trois Fontaines (eastern France), 51 sets of twins were ear-tagged as newborns and then intensively monitored until adulthood (to ≥4 yr of age). On the island of Storfosna (central western Norway), 79 sets of twins and 40 sets of triplets were radiotracked from birth to ≥1 mo of age. In both populations, family effects were observed for measures of early body development and winter body mass. Measurements for sibling fawns were more similar than the same measures for nonsiblings. During unfavorable years (i.e., poor deer survival in summer or high population density), sibling fawns survived or died together much more often than expected by chance. Conversely, during favorable years (i.e., high fawn survival or low density), there was no evidence for family effects on survival of either twins or triplets. These re...

Time- and sex-specific summer survival of roe deer fawns was estimated using capture-mark-recapture methods in two enclosed populations living in contrasting conditions. The population of Trois Fontaines (eastern France) was roughly constant in size throughout the study period, while in Chizé (western France), the population experienced frequent summer droughts and numbers decreased continuously during the study. Early survival of fawns was low and highly variable over the years at both Chizé and Trois Fontaines, and demonstrated marked variations between cohorts that need to be taken into account when modelling roe deer population dynamics. In Trois Fontaines, fawn survival was positively correlated with early body growth and total rainfall in May and June. In Chizé, fawn survival decreased with increasing density and tended to increase with increasing rainfall in May and June and adult female body mass. These factors explained more than 75% of the variability in early survival observed in both populations. Variation between cohorts had different consequences for the two populations. At Trois Fontaines, cohort variation was limited to a numerical effect on early survival. However at Chizé, cohort variation was long-lasting and affected the phenotypic quality of survivors at later ages, and thereby future survival and breeding abilities (both numerical and quality effects). Male and female fawns had similar survival over their first summer in both populations. This result contrasts with the lower survival of young males often observed in ungulates. Two ultimate causes can be proposed to account for the low and variable survival of roe deer fawns over the first summer: the high energy expenditures incurred by does during each breeding attempt and/or the low absolute body size of newborn roe deer fawns.

International audience; There is increasing evidence that environmental conditions experienced early in life can markedly affect an organism's life history, but the pathways by which early environment influences adult phenotype are poorly known. We used long-term data from two roe deer (Capreolus capreolus) populations (Chize' and Trois-Fontaines, France) to investigate the direct and indirect (operating through fawn body mass) effects of environmental conditions during early life on adult body mass. We found that environmental conditions (population size and spring temperatures) around birth influenced body mass of adult females through both direct and indirect effects in both populations. The occurrence of direct effects means that, for a given fawn body mass, adult female mass decreases with adverse conditions in early life. In contrast, we found no evidence for direct effects of early-life conditions on adult body mass of males, suggesting the existence of sex-specific long-term responses of body mass to stressful early conditions. Our results provide evidence that early environmental conditions influence the adult phenotype through persistent effects over the body development in wild mammal populations.

Declines in survival and reproduction with age are prevalent in wild vertebrates, but we know little about longitudinal changes in behavioral, morphological, or physiological variables that may explain these demographic declines. We compared age-related variation in body mass of adult females in three free-living ungulate populations that have been the focus of long-term, individual-based research: bighorn sheep (Ovis canadensis) at Ram Mountain, Canada; roe deer (Capreolus capreolus) at Trois Fontaines, France; and Soay sheep (Ovis aries) on St. Kilda, Scotland. We use two recently proposed approaches to separate contributions to age-dependent variation at the population level from within-individual changes and between-individual selective disappearance. Selective disappearance of light individuals in all three populations was most evident at the youngest and oldest ages. In later adulthood, bighorn sheep and roe deer showed a continuous decline in body mass that accelerated with age while Soay sheep showed a precipitous decrease in mass in the two years preceding death. Our results highlight the importance of mass loss in explaining within-individual demographic declines in later adulthood in natural populations. They also reveal that the pattern of senescence, and potentially also the Processes underlying demographic declines in late life, can differ markedly across related species with similar life histories.

The impact of parasites on population dynamics is well documented, but less is known on how host population density affects parasite spread. This relationship is difficult to assess because of confounding effects of social structure, population density, and environmental conditions that lead to biased among-population comparisons. Here, we analyzed the infestation by two groups of nematodes (gastro-intestinal (GI) strongyles and Trichuris) in the roe deer (Capreolus capreolus) population of Trois Fontaines (France) between 1997 and 2007. During this period, we experimentally manipulated population density through changes in removals. Using measures collected on 297 individuals, we quantified the impact of density on parasite spread after taking into account possible influences of date, age, sex, body mass, and weather conditions. The prevalence and abundance of eggs of both parasites in females were positively related to roe deer density, except Trichuris in adult females. We also found a negative relationship between parasitism and body mass, and strong age and sex-dependent patterns of parasitism. Prime-age adults were less often parasitized and had lower fecal egg counts than fawns or old individuals, and males were more heavily and more often infected than females. Trichuris parasites were not affected by weather, whereas GI strongyles were less present after dry and hot summers. In the range of observed densities, the observed effect of density likely involves a variation of the exposure rate, as opposed to variation in host susceptibility.

We examined timing and synchrony of births in a highly productive population of roe deer ( Capreolus capreolus ) during 5 consecutive years. Neither among-year differences in average date of fawning nor among-year differences in the dispersion of births occurred. Births were synchronized in all years; 80% of births took place in

Little is known about traits under sexual selection in territorial mammals with low sexual size dimorphism. We examined the potential for sexual selection on male body mass and antler length in the European roe deer Capreolus capreolus, a territorial ungulate in which males are less than 10% heavier than females. Independently, both body mass and antler length (irrespective of age) had a positive effect on male yearly breeding success. However, when corrected for body mass, antler length at a given mass only had a slight effect on male breeding success. This suggests that: (1) ‘bigger is better’ and (2) sexual selection is responsible for at least part of the observed variation in body mass and antler length in roe deer. High body mass and large antlers may be advantageous to males for two reasons: (1) they enhance fighting ability and dominance, so allowing males to defend better their territory and hence access mates, and (2) they attract females because they are honest signals of male phenotypic quality. This suggests that, even in weakly dimorphic ungulate species, sexual selection may lead to a marked influence of body mass on male breeding success, as long as body mass is also strongly selected in females.

International audience; We quantified the repeatability of >900 individual measures of hind foot length from 2 French populations of roe deer (Capreolus capreolus) monitored by capture–recapture. We found a high repeatability (i.e., high intra-class correlation, 0.76, 95% CI = 0.72–0.83 and 0.92, 95% CI = 0.91–0.95) in both populations. We also found that inexperienced observers reached a high level of intra- (1.00, 95% CI = 0.96–1.00) and inter-observer repeatability (0.99, 95% CI = 0.98–1.00) when measuring hind foot length of harvested animals with a tool specifically designed for this task. Managers should pay particular attention to limit measurement errors because unreliable measurements require an increased sample size to assess individual variation and can mask biological patterns.

1. Environmental conditions shape population growth through their impact on demographic parameters. While knowledge has accumulated concerning the effects of population density and climatic conditions, a topical question now concerns how predation and harvest influence demographic parameters and population growth (lambda). 2. We performed a comparative demographic analysis based on projection matrix models for female roe deer. Population-specific matrices were parameterized based on longitudinal data from five intensively monitored populations in Norway and France, spanning a large variability in environmental characteristics such as densities of large predators, hunter harvest and seasonality. 3. As expected for a large iteroparous vertebrate, temporal variation was invariably higher in recruitment than in adult survival, and the elasticity of adult survival was consistently higher than that of recruitment. However, the relative difference in elasticity of lambda to recruitment and adult survival varied strongly across populations, and was closely correlated with adult survival. 4. Different traits accounted for most of the variance in lambda in different ecological settings. Adult survival generally contributed more in populations with low mean adult survival and low mean growth rate during the study period. Hunters and predators (Eurasian lynx and red foxes) occurred in two of our study populations and contributed substantially to the variance in lambda, accounting for a total of 35% and 70% in the two populations respectively. 5. Across populations, we did not find any evidence that roe deer increased their reproductive output when faced with harsh conditions, resulting in some populations having negative growth rates. 6. Generation time, a measure of the speed of the life-history cycle, increased from less than 4 years in the most productive population ('roe deer heaven') to more than 6 years in declining populations facing predation from lynx, red fox and hunters ('roe deer hell'), and was tightly and inversely correlated with lambda. Such a deceleration of the life cycle in declining populations might be a general feature in large herbivores. 7. Our results shows that the plethora of environmental conditions faced by populations of large herbivores also induce high intraspecific variation in their ranking along the 'fast-slow' continuum of life-history tactics.

We investigated age-specific variation in male yearly breeding success (YBS) using genetic estimates obtained from 2 populations of a territorial ungulate, the European roe deer (Capreolus capreolus). YBS in both populations was markedly age-structured, with 3 distinct stages, supporting the dome-shaped pattern of variation commonly reported for age-dependent variation in life-history traits of ungulates. YBS was low at 2 years of age, peaked at 3–8 years of age, and tended to decline afterwards (senescence). Most males successfully reproduced for the 1st time at 3 years of age, which is well after their physiological maturity. The few successful young males (i.e., 2 year olds) were likely fast-growing individuals that could successfully hold a territory. The high variance in YBS and antler size for old males at Bogesund, Sweden, suggests that only some males of this age class are able to maintain large antlers and, hence, retain their territories.

International audience; Spatial distribution in mammals, and thereby home range size, is influenced by many different factors including body size, sex, age, reproductive status, season, availability of forage, availability of water, fragmentation of landscape, trophic level and intra- and inter-specific competition. Using linear mixed models, we looked for factors shaping the variation in size of spring-summer and winter home ranges for 51 radio-collared adult female roe deer at Trois Fontaines forest, Champagne!Ardenne, France (1996-2005). Home range size of females was larger in winter than in spring!summer, decreased with age, and decreased with increasing quality. Females in low quality areas adjusted the size of their home range to include more patches of habitat so that all female deer obtained similar amounts of food resources (total biomass of 6.7392.34 tons (mean+/-SE) for each home range). Such adjustments of home range size in response to patchiness of resources led to marked between-female variation in home range size. Our results demonstrate that roe deer females have different tactics of habitat use according to spatial variations in habitat quality so that females get similar food resources in highly productive environments such as the Trois Fontaines forest.

Publis009-cbgp-060; International audience; Heterozygosity-fitness correlations (HFCs) are increasingly reported but the underlying mechanisms causing HFCs are generally poorly understood. Here, we test for HFCs in roe deer (Capreolus capreolus) using 22 neutral microsatellites widely distributed in the genome and four microsatellites in genes that are potentially under selection. Juvenile survival was used as a proxy for individual fitness in a population that has been intensively studied for 30 years in northeastern France. For 222 juveniles, we computed two measures of genetic diversity: individual heterozygosity (H), and mean d(2) (relatedness of parental genomes). We found a relationship between genetic diversity and fitness both for the 22 neutral markers and two candidate genes: IGF1 (Insulin-like Growth Factor I) and NRAMP (natural resistance-associated macrophage protein). Statistical evidence and the size of genetic effects on juvenile survival were comparable to those reported for early development and cohort variation, suggesting a substantial influence of genetic components on fitness in this roe deer population. For the 22 neutral microsatellites, a correlation with fitness was revealed for mean d(2), but not for H, suggesting a possible outbreeding advantage. This heterosis effect could have been favored by introduction of genetically distant (Hungarian) roe deer to the population in recent times and, possibly, by the structuring of the population into distinct clans. The locus-specific correlations with fitness may be driven by growth rate advantages and resistance to diseases known to exist in the studied population. Our analyses of neutral and candidate gene markers both suggest that the observed HFCs are likely mainly due to linkage with dominant or overdominant loci that affect fitness ("local" effect) rather than to a genome-wide relationship with homozygosity due to inbreeding ("general" effect).

We examined the relationship between survival of roe deer (Capreolus capreolus) fawns at Trois Fontaines, Champagne-Ardennes, France, and factors related to bed-site selection (predator avoidance and thermoregulation) and maternal food resources (forage availability in the maternal home range). Previous studies have demonstrated that at small scales, the young of large herbivores select bed sites independently from their mothers, although this selection takes place within the limits of their mother’s home range. Fawn survival was influenced largely by the availability of good bed sites within the maternal home range, not by the fawn’s selection of bed sites; however, selection for thermal cover when selecting bed sites positively influenced survival of young fawns. Typical features of a good home range included close proximity to habitat edges, which is related to forage accessibility for roe deer. The availability of bed sites changed as fawns aged, probably due to an increased mobility of the fawn or a different use of the home range by the mother; sites offering high concealment and thermal protection became less available in favor of areas with higher forage accessibility. Despite the minor influence of bed-site selection on survival, roe deer fawns strongly selected their bed sites according to several environmental factors linked to predator avoidance and thermoregulation. Fawns selected for sites providing concealment, light penetration, and avoided signs of wild boar (Sus scrofa) activity. Avoidance of sites with high light penetration by young fawns positively affected their survival, confirming a negative effect on thermoregulation due to reduced thermal cover. Selection for light penetration by older fawns was less clear. We discuss these results in the context of cross-generational effects in habitat selection across multiple scales, and the potential influence of the ‘ghost of predation past’.

International audience; The relationship between individual performance and nonrandom use of habitat is fundamental to ecology; however, empirical tests of this relationship remain limited, especially for higher orders of selection like that of the home range. We quantified the association between lifetime reproductive success (LRS) and variables describing lifetime home ranges during the period of maternal care (spring to autumn) for 77 female roe deer (Capreolus capreolus) at Trois-Fontaines, Champagne-Ardenne, France (1976–2000). We maintained population growth rate (adjusted to account for removals of non-focal animals) near rmax, which enabled us to define the fitness–habitat relationship in the absence of density effects. Using a negative binomial model, we showed that a roe deer's incorporation into its home range of habitat components important to food, cover, and edge (meadows, thickets, and increased density of road allowances) was significantly related to LRS. Further, LRS decreased with increasing age of naturally reclaimed meadows at the time of a deer's birth, which may have reflected a cohort effect related to, but not entirely explained by, a decline in quality of meadows through time. Predictive capacity of the selected model, estimated as the median correlation (rs) between predicted and observed LRS among deer of cross-validation samples, was 0.55. The strength of this relationship suggests that processes like selection of the site of a home range during dispersal may play a more important role in determining fitness of individuals than previously thought. Individual fitness of highly sedentary income breeders with high reproductive output such as roe deer should be more dependent on home range quality during the period of maternal care compared to capital breeders with low reproductive output. Identification of the most important habitat attributes to survival and reproduction at low density (low levels of intraspecific competition) may prove useful for defining habitat value (‘‘intrinsic habitat value'').

International audience; Identifying factors shaping secondary sexual traits is essential in understanding how their variation may influence male fitness. Little information is available on the allocation of resources to antler growth in territorial ungulates with low sexual size dimorphism. We investigated phenotypic and environmental factors affecting both absolute and relative antler size of male roe deer in three contrasting populations in France and Sweden. In the three populations, we found marked age-specific variation in antler size, with an increase in both absolute and relative antler size between yearling and prime-age stages, followed by a decrease ( senescence) for males older than 7 years. Antler size increased allometrically with body mass. This increase was particularly strong for senescent males, suggesting the evolution of two reproductive tactics: heavy old males invested particularly heavily in antler growth ( potentially remaining competitive for territories), whereas light old males grew small antlers ( potentially abandoning territory defense). Finally, environmental conditions had little effect on antler size: only population density negatively affected absolute antler size in one of the three populations. Antler size may therefore provide an honest signal of male phenotypic quality in roe deer. We discuss the implications of these results in terms of territory tenure and mating competition.

International audience; Animals in seasonal environments are affected by climate in very different ways depending on season and part of the climatic effects operates indirectly through the plants. Vegetation conditions in spring and summer are regarded as decisive for the reproductive success and the offspring's condition of large herbivores, but objective ways to determine key periods during the growing season have not been done often due to limitations in plant data. Using satellite data (NDVI), we determined how plant productivity from birth to fall influences the following winter body mass of roe deer fawns. We do this in two populations, the first inhabiting the low productive Chize´ reserve in south western France with an oceanic climate and the second from Trois Fontaines, a highly productive forest with continental climate in east France. The effect of plant productivity was similar for male and female fawn mass, as expected from the weak intensity of sexual selection in roe deer life history traits. We found contrasting results between sites, with a strong effect of plant productivity in spring (April-May) in the Chize´ population, but no effect in the Trois Fontaines population. The relatively low variability in winter fawn body mass could account for the absence of NDVI effects at Trois Fontaines. However, such results might also point to a limitation in the use of the NDVI, since the relationship between the canopy and the plant productivity at the ground level might be weak in the highly productive forest of Trois Fontaines.

10 PAGES; International audience; 1. Temporal and spatial variation can strongly affect life-history traits, but few studies to date have quantified the importance of the interplay between temporal and spatial components of population dynamics. 2. We analysed spatiotemporal variation in early survival of roe deer fawns over 15 years (1985–99) in an intensively monitored population in western France at two spatial scales: the maternal home range (a few tens of hectares) and the forest stand (a few hundreds of hectares). 3. Spatial variation in resource availability interacted with temporal variation to shape fawn survival. In good years, survival was not influenced by habitat quality (being 0·68 in the rich oak stand with hornbeam coppices vs. 0·64 in the poorer part of the reserve). At the home range scale, early survival of fawns during good years decreased with increasing occurrence of preferred plant species in the rich habitat; there was no effect in the poor habitat. 4. During bad years, however, there was a positive relationship between the occurrence of preferred plant species and survival of fawns in the poor habitat, whereas no relationship occurred in the rich habitat. Spatial variation in early survival during bad years was significant at the plot scale (from 0·19 to 0·40 in the poor habitat and from 0·49 to 0·61 in the rich habitat) even after accounting for the forest stand variations (from 0·27 to 0·51). The occurrence of key plant species therefore limits female reproductive success only in the poor habitat under harsh conditions. 5. Our findings highlight the crucial role of spatiotemporal interactions in shaping individual fitness in mammalian populations, and underline the importance of the scale of analysis when characterizing ecological processes.

International audience; How mothers allocate resources to offspring is central to understanding life history strategies. High quality mothers are predicted to favour investment in sons over daughters when to do so increases inclusive fitness. This is the case in ungulates with polygynous mating systems, where reproductive success is more variable among males than females, but information is scarce on sex allocation in less polygynous species. Here, for the weakly dimorphic roe deer, we show that as maternal capacity to invest increases, mothers increase allocation to daughters more than to sons, so that relative allocation to daughters increases markedly with increasing maternal quality. This cannot be explained by a between sex difference in growth priority, hence we conclude that this is evidence for active maternal discrimination. Further, we demonstrate that condition differences between offspring persist to adulthood. For high quality mothers of weakly polygynous species, daughters may be more valuable than sons

10 pages; International audience; We analyzed spatial variations in movements and survival in a roe deer (Capreolus capreolus) population (Chize´, western France) by using recent developments of multistate capture–mark–recapture modeling in order to estimate transition and survival probabilities of individuals living in three habitats of contrasting quality. Irrespective of both population density and sex, habitat quality did not influence survivorship of primeage or senescent roe deer. Likewise, habitat quality did not influence fawn survival at low density. On the other hand, fawn survival at high density was 20% higher in the resourcerich hornbeam-dominant coppices than in the other poorer habitats. We found, as expected, that fawns were mobile, whereas adults of both sexes were highly sedentary. Movements of roe deer among habitats were markedly influenced by habitat quality. Transition probabilities of individuals from the rich hornbeam coppices toward other habitats were lower than transition probabilities of individuals from the poor beech stand or from the mediumquality maple dominant coppices toward the rich hornbeam coppices

Among-individual variation of life history traits in a given population of deer has most often been accounted for by differences among sex and age classes and by current environmental variation (mostly changes in density and climatic conditions). However, among-individual differences in fitness can also be generated by differences in environmental conditions during the year of birth. Such cohort effects can be divided into two different components. First, among-year differences in environmental conditions at birth may produce large yearly variation in recruitment that generates a direct numerical effect (i.e., a high proportion of newborns are recruited in good years, whereas very low proportions are recruited when environmental conditions encountered by newborns during their first weeks of life are poor). Second, when recruited into the population, individuals born in a good year may reproduce earlier, reach a larger body mass, and have a higher reproductive success than individuals born in a poo...

International audience; Patterns of sex ratio variation and maternal investment reported in the literature are often inconsistent. This could be due to intra- and inter-specific variation in social systems, but may also be a result of the a posteriori nature of much of this type of analysis or the testing of models which are inappropriate. Two recent papers reported directly opposed results concerning variation in offspring sex ratios in relation to maternal condition in roe deer, interpreting the results as support for the Trivers and Willard model and for the local resource competition hypothesis, respectively. In this paper, we present data on offspring sex ratios and early juvenile body weight from two long-term studies of this species to test predictions arising from these two models concerning sex biases in litter composition and maternal care. First, we observed no consistent pattern of sex differences in an index of weaning weight or body weight at 1 month old in either population, indicating a lack of sex bias in maternal care. However, in one population, higher maternal body weight was associated with higher juvenile body weight of daughters, but not of sons. Secondly, we found a negative, but not statistically significant, relationship between maternal body weight and litter sex ratio such that heavier females tended to produce more daughters and lighter females to produce more sons. These results indicate that roe females which have additional investment potential available do not invest it in sons, as predicted by the Trivers and Willard model. Our results may provide some support that roe deer are subject to local resource competition acting at the level of the individual mother; however, the fact that particular trends in sex ratio data can be explained in functional terms provides no indication that they are actually adaptive.

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.

From two enclosed populations monitored for 13 and 11 years, time- and age-specific survival rates of roe deer were estimated in relation to age and study site by recent capture-mark-recapture methods. The two populations were very different. Roe deer in Trois Fontaines, a 1360 ha reserve in east France, faced severe winters. The size of this highly productive population was roughly constant during the study period. Conversely, in Chize, a 2660 ha reserve in west France with mild winters, roe deer showed density dependence in reproduction and body weight. As a general rule, females survived better than males, the survival rates of prime-age adults were the highest, and survival decreased after 7 years of age. Only the severe winters affected markedly the survivorship of roe deer

We investigated the effects of the year of birth (cohort effect), sex and birth date on the variations observed in birth weight and postnatal growth rate in 209 newborn fawns marked during eight consecutive fawning seasons from a highly productive roe deer population under good nutritional conditions. Roe deer exhibited a fast body development with a birth weight of 1628 g and a postnatal growth rate of 139 g/day constant over the first 20 days of their life. As previously reported for dimorphic and polygynous ungulates, there was a marked cohort effect on the rate of body development. This variability was partly explained by climatic conditions during late gestation. When fewer than 5 days with rainfall over 5 mm occurred in April, fawns were heavier. High temperatures during April and during the winter could also be involved in fast body development of roe deer fawns. Sex of fawn did not affect roe deer growth pattern. This was expected on the basis of low sexual dimorphism in size and low polygyny level characteristic of roe deer. Lastly, the date of birth did not affect the body development of roe deer fawns. High constancy of mean birth dates and high synchrony of births observed in this population could account for this result.

International audience; Although extreme weather events—such as hurricanes—cause obvious changes in landscape and tree cover, the impact of such events on population dynamics of ungulates has not yet been measured accurately. We report a first quantification of the demographic consequences on roe deer (Capreolus capreolus) of the strongest hurricane (Lothar) that France has suffered in centuries. Based on long-term monitoring (>20 yr) of known-age individuals in 2 populations, we found that Lothar had no detectable negative effect on age- and sex-specific survival rates, except perhaps for old females. Likewise, although Lothar occurred during the time in the roe deer reproductive cycle when embryos are implanted, we found no evidence of a decrease in either the pregnancy rate or litter size. Our results show that roe deer populations are resistant to this kind of extreme weather event. The consequences for wildlife management are direct and important: (1) the hunting bag was low in 2000 due to restricted hunter access, and (2) the main effect of hurricane Lothar was to create openings within large forests that are good habitat for roe deer. We suggest that Lothar will paradoxally have a positive effect on roe deer population dynamics.

Because first-year survival and age at sexual maturity of northern ungulates often depend on body mass of fawns during winter, knowledge of factors affecting body mass of fawns is necessary to understand population dynamics and management of ungulates in temperate regions. Therefore, we compared body mass of roe deer (Capreolus capreolus) fawns during winter in two enclosed populations with contrasting climatic and demographic characteristics: Chize (CH) in western France (mild winters, less abundant food and lower birthrates), and Trois Fontaines (TF) in eastern France (cold winters, abundant food and high birthrates). We weighed 2,077 fawns (1,212 in TF and 865 in CH) of both sexes captured with drive-nets in January and February from 1976 to 1993. Mass of male fawns was greater than of females in both populations (P < 0.01). Body mass varied among years for both sexes in each population (P < 0.01 in CH; P < 0.01 in TF). Neither climatic conditions between April and December nor population density accounted for yearly variation in body mass of fawns in TF. Rather, body mass fluctuated randomly about a mean, with no longterm effects on population dynamics. By contrast, body mass of fawns in CH was correlated with mean daily temperature in June-July (P = 0.01 for males; P = 0.04 for females) and population density (P = 0.02 for males; P = 0.03 for females). Body mass of fawns was greater in years following cool summers and in years of low population density (r 2 = 0.75, P < 0.01 for males; r 2 = 0.50, P = 0.02 for females). Mass of male fawns but not female fawns was greater in January-February when total rainfall in the previous April-May was low (P = 0.01). In CH, yearly variation in fawn body mass supports the range quality hypothesis which states that fawns entering winter are small owing to poor nutritional conditions the previous summer or high population density. As a consequence, yearly variations in body mass probably have long-lasting effects on population dynamics in CH.