# Effects of forest structure on the endoparasitism in roe deer Capreolus capreolus

## TL;DR

This study examines how forest structure affects endoparasitism in roe deer, finding that habitat quality influences infection risk.

## Contribution

The study reveals that habitat quality, at a fine scale, affects parasite prevalence in roe deer populations.

## Key findings

- Parasite prevalence was higher in roe deer from the poorer habitat sector.
- Forest structure and resource availability likely influence infection risk.
- Parasite intensity was not affected by the habitat sector.

## Abstract

Parasitic infection by endoparasites is heterogeneous within a population. Such heterogeneity in parasitic status among individuals depends in particular on differences in their susceptibility to infection and in the habitats and resources used by the individuals. While several studies have aimed to identify individual factors and, mostly at large spatial scales, environmental factors that influence endoparasitism in wild populations, we aim in this study to investigate the influence of habitat quality (vegetation type, resource availability) on parasite burden within a population of roe deer living in a heterogeneous forest. We collected 1,469 fecal samples to measure the parasite burden on 952 roe deer captured between 1996 and 2020 in Chizé (France), a study site stratified into two contrasting sectors in terms of vegetation structure and resource quality. We quantified the effect of the sector on parasitism after considering the possible influences of age, sex, body mass and Julian date. The prevalence of parasitism was higher in individuals living in the poorer sector, but the intensity of the parasite burden was not influenced by the sector. These results suggest that within a host population, parasite infection risk would not be the same everywhere, probably due to differences in resource availability, vegetation species and density of host, showing the need to study parasitism at fine scales.