Host‐related and environmental factors influence long‐term ectoparasite infestation dynamics of mouse lemurs in northwestern Madagascar

Abstract

Parasite infestations depend on multiple host‐related and environmental factors. In the case of ectoparasites, which are exposed to the environment beyond the host, an impact of climate, expressed by seasonal or yearly variations, can be expected. However, long‐term dynamics of ectoparasite infestations are rarely studied in nonhuman primates. We investigated the yearly variations in ectoparasite infestations of two small primates, the gray (Microcebus murinus) and the golden‐brown (Microcebus ravelobensis) mouse lemur. For a more comprehensive evaluation, we also analyzed the potential effects of yearly and monthly climatic variation (temperature, rainfall) in addition to habitat, host sex, age, species, and body mass, on ectoparasite infestation. Individuals of both host species were sampled in two study sites within the Ankarafantsika National Park in northwestern Madagascar during several months (March–November) and across 4 years (2010, 2011, 2015, 2016). Our results show significant monthly and yearly variations in the infestation rates of three native ectoparasite taxa (Haemaphysalis spp. ticks, Schoutedenichia microcebi chigger mites, Lemurpediculus spp. sucking lice) and in ectoparasite species richness in both mouse lemur species. In addition, significant impacts of several host‐related (species, sex, body mass) and environmental factors (habitat, temperature, rainfall) were found, but with differences in relevance for the different parasite taxa and partly deviating in their direction. Although some differences could be attributed to either permanent or temporary presence of the parasites on the host or to ecological differences between the host species, the lack of specific knowledge regarding the life cycle and microhabitat requirements of each parasite taxon precludes a complete understanding of the factors that determine their infestation dynamics. This study demonstrates the presence of yearly and monthly dynamics in lemur–parasite interactions in tropical, seasonal, dry deciduous forests in Madagascar, which call out for broad ecological long‐term studies focusing both on primate hosts and their parasites.

Forest fragmentation and edge effects impact body condition, fur condition and ectoparasite prevalence in a nocturnal lemur community

“…As increased parasite prevalence in primates has been reported for fragmented and edge habitats previously ( Gillespie et al., 2005 ; Chapman et al., 2006 ; Gillespie and Chapman, 2008 ; Mbora and McPeek, 2009 ; Schwitzer et al., 2011 ), our significant pairwise results are as expected and conform to our original predictions. Fragmentation and edge effects increase the environmental stress of potential ectoparasite hosts and therefore their susceptibility to ectoparasite infestations ( Kiene et al., 2020 ; Kiene et al., 2021 ), and the abundance of primate parasites may be elevated in edge habitat due to a range of environmental, climatic and anthropogenic factors ( Chapman et al., 2006 ; Marquès Gomila et al., 2023 ). The higher abundance of parasites and the increased susceptibility to them may therefore explain our observations of higher tick/mite prevalence in edge habitat for M. zaza and L. sahamalaza .…”