[PhD defence] 24/06/2025 - Cloé JOLY: "Ecology, ethology and parasite dynamics in pastures: the zebra, its gastrointestinal parasites and coprophagous beetles" (UPR 406 - AE - Abeilles et Environnement)

Ms Cloe JOLY will publicly defend her thesis entitled: "Ecology, ethology and parasite dynamics in pastures: the zebra, its gastrointestinal parasites and coprophagous beetles" on Tuesday 24 June 2025 at 1pm.

Laboratory

UPR 406 - AE - Bees and the Environment

Composition of the jury

Mrs Freddie-Jeanne RICHARD	Avignon University	Thesis supervisor
Ms Marion VITTECOQ	Research Institute for the Conservation of Mediterranean Wetlands La Tour du Valat	Rapporteur
Mickael HEDDE	INRAE, UMR Eco & Sols	Rapporteur
Ms Julie BRUNET	Strasbourg Institute of Parasitology and Tropical Pathology (IPPTS)	Examiner
Thierry DUTOIT	IMBE - UMR CNRS 7263	Examiner
Mr Pierre JAY-ROBERT	University of Montpellier Paul-Valéry	Thesis co-director
Ms Alix ORTEGA	The Sigean African Reserve	Thesis co-director
Mr Antoine JORIS	The Sigean African Reserve	Guest

Summary

The 1970s marked the start of the marketing of the main anti-parasite molecules. Since then, farm animals have been regularly and systematically treated, often in overdoses. These practices have led to the emergence of parasites that are resistant to anti-parasitics, and to significant environmental pollution. Several studies report a negative impact of this pollution on most soil arthropods, some of which play a major role in controlling herbivore parasites present in manure. The research presented in this manuscript takes place in the context of zoological parks, whose entertainment activities are now supplemented by education, animal welfare, research and conservation missions. We looked at the ecology of pastures in multi-species herbivore enclosures, using three biological models affected by the use of antiparasitics: equids, their gastrointestinal parasites and coprophagous beetles. The work presented was carried out along two main lines of investigation. In the first, we examined the host-parasite relationship in Grant's Zebra (Equus quagga boehmi). The three studies presented use individual parasite and behavioural monitoring to improve existing rational deworming methods. We were interested in the predictors of variation in faecal excretion of strongyle eggs, with or without the administration of antiparasitics. In the first part of this thesis, we showed that social behaviour is a determining factor in the rate of re-excretion after antiparasitic treatment. In addition, we highlighted the importance of climatic conditions, whatever the age, and the importance of periods of social upheaval in young animals, in explaining variations in faecal excretion of strongyles eggs over time. In the second section, we examined how habitat diversity impacts communities of coprophagous beetles. Of the three studies presented, two were based on in situ trapping methods and one on laboratory experiments involving the rearing of the species Onthophagus vacca and carrying out behavioural and physiological tests on the same species. The aim of this second phase was to highlight the link between management practices in herbivore enclosures and coprophagous beetle communities, so as to enable zoo managers to take better account of local wildlife conservation issues. In the second part of this thesis, we showed that the diversity of herbivores does not seem to be a factor in diversity within coprophage communities, even though the herbivores have access to the same food resource. We also highlighted the importance of land use intensity on the abundance and diversity of these communities. Finally, in a last study we looked at the plasticity of the species O. vacca and local evolutionary mechanisms.

Keywords social behaviour, zebras, dung beetles, trophic relationships, host-parasite relationships, pastures