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The balance between resource acquisition and risk avoidance should vary according to personality type, with potential knock-on effects for fitness. Although previous studies have suggested a link between boldness and fitness components, little evidence is available on the behavioural mechanisms mediating this relationship in the wild. Because habitat use is the outcome of the trade-off between the costs and benefits associated with using each habitat type, we evaluated between-individual differences in habitat use of 64 GPS-collared female roe deer, Capreolus capreolus , using multinomial logit mixed models. To investigate whether deer differed in their habitat use tactics in relation to their personality type and their annual reproductive success, we assessed the link between individual habitat use patterns, boldness (measured as the strength of behavioural responsiveness to handling) and annual reproductive success (measured by the presence/absence of fawns at heel during autumn). Although daily and seasonal variations in the risk–resource landscapes clearly drove patterns of habitat use, individuals adopted contrasting habitat use tactics depending on their position along the shy–bold gradient and their reproductive status. Shy individuals occupied safer woodland more frequently, even at night when risk is lower. In contrast, bold individuals were better able to exploit rich open habitats. When this included mature autumn crops, these females weaned more offspring. Finally, irrespective of personality type, females that used meadows more often also achieved higher annual reproductive success. Overall, we demonstrate that individuals express divergent habitat use tactics as a function of their ability to avoid exposure to risk and their annual reproductive success. Highlights • We measured habitat use, boldness and reproductive success in 64 female roe deer. • Spatiotemporal variations in the risk-resource trade-off shape deer habitat use. • The way individuals use their environment also depends on their personality type. • Differences in habitat use between personalities are linked to reproductive success. • Individual habitat use tactics mediate the personality – fitness link in the wild. [ABSTRACT FROM AUTHOR]

Parasite abundance has been shown to have major consequences for host fitness components such as survival and reproduction. However, although natal dispersal is a key life history trait, whether an individual's decision to disperse or not is influenced by the abundance of parasites it carries remains mostly unknown. Current and opposing hypotheses suggest that infected individuals should either be philopatric to avoid the energetic costs of dispersal (condition dependence) or disperse to escape from heavily parasitised habitats. From intensive monitoring of a roe deer population inhabiting a multi-use and spatially heterogeneous agricultural landscape, we evaluated the link between an individual's parasite abundance and its propensity to disperse, while accounting for confounding effects of body mass. Dispersal propensity generally decreased with both increasing nematode abundance and with decreasing body mass. Within the dispersing segment of the population, individuals with high nematode abundance left their natal home range later in the season than less parasitised deer. These results clearly show that parasite abundance is an important component of condition-dependent dispersal in large herbivores. However, unexpectedly, three individuals that were both heavily parasitised and of low body mass dispersed. We suggest that this 'leave it' response to high parasite levels in the natal habitat could represent a last ditch attempt to improve reproductive prospects, constituting a form of emergency life history strategy. [ABSTRACT FROM AUTHOR]

Forest fragmentation may benefit generalist herbivores by increasing access to various substitutable food resources, with potential consequences for their population dynamics. We studied a European roe deer ( Capreolus capreolus) population living in an agricultural mosaic of forest, woodlots, meadows and cultivated crops. We tested whether diet composition and quality varied spatially across the landscape using botanical analyses of rumen contents and chemical analyses of the plants consumed in relation to landscape metrics. In summer and non-mast winters, roe deer ate more cultivated seeds and less native forest browse with increasing availability of crops in the local landscape. This spatial variation resulted in contrasting diet quality, with more cell content and lower lignin and hemicellulose content (high quality) for individuals living in more open habitats. The pattern was less marked in the other seasons when diet composition, but not diet quality, was only weakly related to landscape structure. In mast autumns and winters, the consumption of acorns across the entire landscape resulted in a low level of differentiation in diet composition and quality. Our results reflect the ability of generalist species, such as roe deer, to adapt to the fragmentation of their forest habitat by exhibiting a plastic feeding behavior, enabling them to use supplementary resources available in the agricultural matrix. This flexibility confers nutritional advantages to individuals with access to cultivated fields when their native food resources are depleted or decline in quality (e.g. during non-mast years) and may explain local heterogeneities in individual phenotypic quality. [ABSTRACT FROM AUTHOR]