Metabarcoding in two isolated populations of wild roe deer (Capreolus capreolus) reveals variation in gastrointestinal nematode community composition between regions and among age classes.

Background: Gastrointestinal nematodes are ubiquitous for both domestic and wild ungulates and have varying consequences for health and fitness. They exist as complex communities of multiple co-infecting species, and we have a limited understanding of how these communities vary in different hosts, regions and circumstances or of how this affects their impacts.

Methods: We have undertaken ITS2 rDNA nemabiome metabarcoding with next-generation sequencing on populations of nematode larvae isolated from 149 fecal samples of roe deer of different sex and age classes in the two isolated populations of Chizé and Trois Fontaines in France not co-grazing with any domestic ungulate species.

High juvenile mortality is associated with sex-specific adult survival and lifespan in wild roe deer.

Male mammals typically have shorter lifespans than females [1]. Sex differences in survival may result, in part, from sex-specific optima in investment in reproduction, with higher male mortality rates from sexual competition selecting for a "live-fast die-young" strategy in this sex [2]. In the wild, lifespan is also influenced by environmental conditions experienced early in life.

Reduced microsatellite heterozygosity does not affect natal dispersal in three contrasting roe deer populations.

Although theoretical studies have predicted a link between individual multilocus heterozygosity and dispersal, few empirical studies have investigated the effect of individual heterozygosity on dispersal propensity or distance. We investigated this link using measures of heterozygosity at 12 putatively neutral microsatellite markers and natal dispersal behaviour in three contrasting populations of European roe deer (Capreolus capreolus), a species displaying pre-saturation condition-dependent natal dispersal. We found no effect of individual heterozygosity on either dispersal propensity or dispersal distance.

Fitness consequences of environmental conditions at different life stages in a long-lived vertebrate.

The predictive adaptive response (PAR) hypothesis proposes that animals adjust their physiology and developmental trajectory during early life in anticipation of their future environments. Accordingly, when environmental conditions in early life match environmental conditions during adulthood, individual fitness should be greater. Here, we test this hypothesis in a long-lived mammal, the roe deer, using data from two contrasting populations, intensively monitored for more than 35 years.

Variation in adult body mass of roe deer: early environmental conditions influence early and late body growth of females.

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 (Chizé 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.

Detection of Wolbachia in the tick Ixodes ricinus is due to the presence of the hymenoptera endoparasitoid Ixodiphagus hookeri.

The identification of micro-organisms carried by ticks is an important issue for human and animal health. In addition to their role as pathogen vectors, ticks are also the hosts for symbiotic bacteria whose impact on tick biology is poorly known. Among these, the bacterium Wolbachia pipientis has already been reported associated with Ixodes ricinus and other tick species.