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In most previous studies of habitat selection, the use of a given habitat type is assumed to be directly proportional to its availability. However, the use and (or) the selection of a given habitat may be conditional on the availability of that habitat. We aim here to (i) identify the environmental variables involved in habitat selection, (ii) identify classes of individuals with similar patterns of habitat selection, and (iii) assess whether habitat use changes with changing availability of habitat types, within monthly home ranges of female western roe deer (Capreolus capreolus (L., 1758)). We found that some females adjust their habitat use according to the distribution of resources within habitats. Females with similar home ranges in terms of resource quantity and quality showed similar patterns of habitat selection. Differences in habitat use between 2 years with contrasting resource availability showed that temporal changes of environmental conditions influenced the pattern of habitat selection by female roe deer. Habitat selection also differed between periods of the life cycle likely because of contrasted energy requirements. This study shows that the relationship between habitat use by herbivores and habitat availability is nonproportional, and that the availability of resources influences use mostly at intermediate values. Dans la plupart des etudes anterieures sur la selection de l'habitat, l'utilisation d'un habitat donne est supposee etre directement proportionnelle a sa disponibilite. Cependant, l'utilisation et (ou) la selection d'un habitat donne peut etre conditionnelle a la disponibilite de cet habitat. Le but de cette etude est (i) d'identifier les variables environnementales impliqueees dans la selection de l'habitat, (ii) d'identifier les classes d'individus avec des patrons similaires de selection de l'habitat et (iii) de tester si l'utilisation d'habitat change avec une disponibilite; changeante des types d'habitat, dans les domaines vitaux mensuels des femelles chevreuils d'Europe (Capreolus capreolus (L., 1758)). Nous trouvons que certaines femelles ajustent leur utilisation d'habitat en fonction de la distribution des ressources dans les habitats. Les femelles avec des domaines vitaux similaires en termes de quantite et qualite de ressources montrent des patrons de selection de l'habitat similaires. Les differences dans l'utilisation d'habitat entre deux annees avec des disponibilitees de ressources contrasteees montrent que les variations dans le temps des conditions environnementales influencent le patron de selection de l'habitat chez les femelles de chevreuil. La selection de l'habitat differe aussi entre les peeriodes du cycle de vie a cause de besoins en energie bien diffeerencie;s. Cette etude montre que la relation entre l'utilisation et la disponibilite: des habitats est nonproportionnelle, et que la disponibilite des ressources influence l'utilisation, surtout aux valeurs intermediaries., Introduction Habitat selection is a hierarchical process involving behavioural decisions at different spatial scales (Hutto 1985), These decisions may result in disproportional use of some habitats and may lead to [...]

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.

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).

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.

It is well established that the dynamics of mammalian populations vary in time, in relation to density and weather, and often in interaction with phenotypic differences (sex, age and social status). Habitat quality has recently been identified as another significant source of individual variability in vital rates of deer, including roe deer where spatial variations in fawn body mass were found to be only about a tenth of temporal variations. The approach used was to classify the habitat into blocks a priori, and to analyse variation in animal performance among the predefined areas. In a fine-grained approach, here we use data collected over 24 years on 1,235 roe deer fawns captured at known locations and the plant species composition sampled in 2001 at 578 sites in the Chizé forest to determine the spatial structure at a fine scale of both vegetation and winter body mass of fawns, and then to determine links between the two. Space and time played a nearly equal role in determining fawn body masses of both sexes, each accounting for about 20% of variance and without any interaction between them. The spatial distribution of fawn body mass was perennial over the 24 years considered and predicted values showed a 2 kg range according to location in the reserve, which is much greater than suggested in previous work and is enough to have strong effects on fawn survival. The spatial distribution and the range of predicted body masses were closely similar in males and females. The result of this study is therefore consistent with the view that the life history traits of roe deer are only weakly influenced by sexual selection. The occurrence of three plant species that are known to be important food items in spring/summer roe deer diets, hornbeam ( Carpinus betulus), bluebell ( Hyacinthoides sp.) and Star of Bethlehem ( Ornithogalum sp.) was positively related to winter fawn body mass. The occurrence of species known to be avoided in spring/summer roe deer diets [e.g. butcher's broom ( Ruscus aculeatus) and beech ( Fagus sylvatica)], was negatively related to fawn body mass. We conclude that the spatial variation in the body mass of fawns in winter in this forest is as important as the temporal variation, and that the distribution of plant species that are actively selected during spring and summer is an important determinant of spatial variation in winter fawn body mass. The availability of these plants is therefore likely to be a key factor in the dynamics of roe deer populations.

Body mass is a key determinant of fitness components in many organisms, and adult mass varies considerably among individuals within populations. These variations have several causes, involve temporal and spatial factors, and are not yet well understood. We use long-term data from 20 roe deer cohorts (1977-96) in a 2600 ha study area (Chizé, western France) with two habitats contrasting in quality (rich oak forest in the North versus poor beech forest in the South) to analyse the effects of both cohort and habitat quality on adult mass (i.e. median body mass between 4 and 10 years of age) of roe deer (Capreolus capreolus). Cohort strongly influenced the adult body mass of roe deer in both sexes: males born in 1994 were 5.2 kg heavier when aged between 4 and 10 years old than males born in 1986, while females born in 1995 were 4.7 kg heavier between 4 and 10 years old than females born in 1982. For a given cohort, adult males were, on average, 0.9 kg heavier in the rich oak forest than in the poor beech forest. A similar trend occurred for adult females (0.5 kg heavier in the oak forest). The effects of cohort and habitat were additive and accounted for ca. 40% of the variation observed in the adult mass of roe deer at Chizé (males: 41.2%; females: 40.2%). Population density during the spring of the birth accounted for about 35% of cohort variation, whereas rainfall in May-June had no effect. Such delayed effects of density at birth on adult body mass probably affect population dynamics, and might constitute a mechanism by which delayed density-dependence occurs in ungulate populations.

Two novel species of Bartonella isolated from European ruminants are described. Bartonella capreoli sp. nov. was isolated from the blood of roe-deer (Capreolus capreolus) captured in Chizé, France. The type strain is IBS 193T (= CIP 106691T = CCUG 43827T). It is distinct from another European ruminant isolate that originated from a cow from a French herd of 430 dairy cattle. The latter isolate belongs to a novel species named Bartonella bovis Bermond et al. sp. nov. The type strain is strain 91-4T (= CIP 106692T = CCUG 43828T). The two bacteria appeared as small, fastidious, aerobic, oxidase-negative, gram-negative rods. Their biochemical properties were similar to those of members of the genus Bartonella. The sequences of the 16S rRNA and citrate synthase genes obtained from the two type strains were highly related to sequences of the different Bartonella species. Hybridization values when testing type strains of recognized Bartonella species, obtained with the nuclease/trichloroacetic acid method, support the creation of two novel species.

We tested for fine-scale spatial heterogeneity in habitat quality in a roe deer (Capreolus capreolus) population in the Chizé reserve located in western France by measuring spatial variation in the availability and plant nitrogen content of principal and preferred plant species. There were significant differences in habitat quality within the reserve: the principal food plants in spring and summer occurred more frequently in the oak woodland in the north than in the beech woodland in the south of the reserve. Within species, plants in the north had higher nitrogen contents than in the south. There was a positive spatial covariation between habitat quality, local density and fawn body weight: animal densities and fawn body weights were highest in the north, the best habitat (i.e. the habitat with more abundant food of higher quality). These results differ from those recently obtained on red deer (Cervus elaphus). We suggest that spatial organization and foraging behaviour must be accounted for when considering the effect of habitat quality on individual fitness of ungulates.

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.