Biology subjects

Gicquel, M.

Publications and source records attributed to Gicquel, M..

3 recordsLinked to original sources

bioRxiv2026

How do spotted hyaenas respond to decreased prey availability in their clan territories over the last decades?

Climate change can alter predator-prey dynamics by influencing the distribution and movements of migratory prey. Despite increasing research on predator-prey mismatches, how predators respond to changes in prey availability caused by climate change remains largely unknown, particularly for behaviourally flexible species such as central-place foragers. In the Serengeti National Park, Tanzania, increased rainfall in recent decades is thought to have altered the movement patterns of large herds of migratory herbivores, the main prey of spotted hyaenas (Crocuta crocuta) in the park, leading to a decrease in yearly migratory prey presence within hyaena clan territories. Between 1990 and 1994, migratory prey were present within hyena clan territories for about 12% of the year--mainly in May-June and November-December--dropping to just 7% between 2015 and 2019. Using longitudinal data from three Serengeti hyaena clans at the centre of the park monitored between 1990 and 2019, we investigated the impact of the observed decrease in migratory prey presence on the number of observations of hyaenas feeding at carcasses ("feeding events", n = 777), and explored associated changes in hyaena clan size. The vast majority of observed hyaena feeding events involved migratory prey species, with this relative proportion remaining constant throughout the study period. Annual patterns in the number of feeding events closely mirrored annual patterns of migratory prey presence in clan territories, with two distinct peaks mid-year and toward the end of the year. As migratory prey presence in the study clan territories declined over the years, the number of observed feeding events also decreased. However, the size of two out of three clans increased over time, suggesting that the decline in migratory prey presence in clan territories and in the number of observed feeding events did not negatively impact hyaena clans. This absence of decline in clan size may reflect the fact that hyaenas feed within their territories for only a small fraction of the year, although it also invites further investigation into the mechanisms hyaenas may employ to compensate for reduced prey availability and reduced feeding events within their clan territories.

ecology↗

bioRxiv2025

Compromised futures: gastrointestinal parasites reduce survival and recruitment but not reproductive performance in wild female spotted hyenas (Crocuta crocuta)

BackgroundGastrointestinal parasitic (GIP) infections can decrease the survival and reproductive performance of humans and livestock. Even so, the immediate and delayed fitness consequences of GIP in unmanaged wild mammal populations, particularly during the sensitive and energetically demanding early life stage, remain largely unknown. MethodsWe investigate non-invasively the effects of GIP during early life on the survival to adulthood, age at first reproduction and longevity of 68 individually known female spotted hyenas in the Serengeti National Park, Tanzania. We also test whether a high investment in gastrointestinal local immunity (i.e. faecal mucin and immunoglobulin A) and an elevated allostatic load (i.e. faecal glucocorticoid metabolites) decrease these measures of performance, when controlling for resource availability and maternal effects (i.e. maternal social rank) using logistic regression and Cox proportional hazards models. ResultsAncylostoma sp. infections and the level of immunoglobulin A both negatively associate with survival to adulthood, probably because of the damage caused by the parasite and resource allocation trade-off between immunity and maintenance. Conversely, maternal social rank has a positive influence on survival to adulthood and longevity. Immune responses, allostatic load and GIP do not affect the age at first reproduction, suggesting either no effect, a complex interaction between different life stages, or a more immediate time-dependent effect. ConclusionOur study highlights the critical role of GIP infections and maternal effects on early-life fitness and long-term outcomes in females of a wild carnivore, thereby contributing to our understanding of ecological dynamics in unmanaged ecosystems.

ecology↗

bioRxiv2025

Anthropogenic land use exerts selection pressures on the resistome of a wild rodent

Antimicrobial resistance poses a significant global health challenge. However, the factors maintaining antimicrobial resistance genes (ARGs) in wildlife microbiomes remain unclear particularly in species inhabiting human-dominated landscapes. We analysed 875 gut metagenomes from wild house mice (Mus musculus) on German farms between 2016 and 2022 to identify environmental and host determinants of ARG occurrence. Using joint species distribution models, we quantified the influence of landscape, climate and mouse associated characteristics on the occurrence of individual ARGs and on trait dependence among genes. Environmental variables and livestock farming intensity explained more than 21% of ARG variation, whereas host characteristics accounted for less than 10%. Analysis of ARG traits revealed that agricultural land use and exposure to livestock increased the occurrence of mobile ARGs. Pig density was strongly associated with integron-encoded sulfonamide resistance genes and genes conferring tetracycline and beta-lactam resistance. Consistent with these findings, mouse resistomes closely resembled those of livestock manure. Taken together, our results show that landscape conditions, particularly farming intensity, shape the distribution of specific ARGs and mobile ARGs in house mice microbiomes. Understanding the factors impacting ARGs prevalence in wildlife is crucial for determining transmission of antimicrobial resistant microorganisms from animal and environmental reservoirs.

microbiology↗