Lock, L. R. | Search bioRxiv

bioRxiv2025

Longitudinal impacts of habitat fragmentation on Bartonella and hemotropic Mycoplasma dynamics in vampire bats

Habitat fragmentation can have negative impacts on wildlife including increased risk of infectious disease. To assess spatiotemporal changes in pathogen dynamics in vampire bats (Desmodus rotundus) in response to habitat fragmentation, we used general linear mixed models to investigate the influence of site, year, and tree cover on the prevalence of Bartonella and hemotropic Mycoplasma (hemoplasma) in bats in one large and one small forest fragment in northern Belize across seven years. Bartonella was marginally more prevalent in later years, while year and site differences in hemoplasma infections were driven by a peak in prevalence in the third year of the study in the small fragment. Bartonella prevalence increased with forest loss, but only in the large fragment, whereas hemoplasma prevalence showed a marginal negative response to forest loss. The effects of site, year, and forest loss on infection likelihood varied by pathogen genotype. Neither site nor year affected Bartonella genotypes, but one genotype was positively associated with tree cover. Two hemoplasma genotypes were influenced by year, but with differing trends. One genotype increased with tree cover regardless of site while another increased with forest loss at the small fragment only. Our work demonstrates that the effects of habitat fragmentation on infection prevalence depended on both the pathogen and specific genotype. Our findings complicate expectations of how habitat fragmentation affects infectious disease dynamics in bats. As such, management practices aimed at mitigating the impacts of infectious diseases in fragmented systems should be tailored to specific pathogens of concern.

ecology↗

bioRxiv2023

Bat cellular immunity varies by year and dietary habit in an increasingly fragmented landscape

Monitoring the health of wildlife populations is essential in the face of increased agricultural expansion and forest fragmentation. Loss of habitat and habitat degradation can negatively affect an animals physiological state, possibly resulting in immunosuppression and increased morbidity or mortality. We sought to determine how fragmentation may differentially impact cellular immunity and infection risk in Neotropical bats species regularly infected with bloodborne pathogens, and to evaluate how effects may vary over time and by dietary habit. We studied common vampire bats (Desmodus rotundus), northern yellow-shouldered bats (Sturnira parvidens), and Mesoamerican mustached bats (Pteronotus mesoamericanus), representing the dietary habits of sanguinivory, frugivory, and insectivory respectively, in northern Belize. We compared estimated total white blood cell counts, leukocyte differentials, and infection status with two blood-borne bacterial pathogens (Bartonella spp. and hemoplasmas) of 118 bats captured in a broadleaf, secondary forest over a three-year period (2017-2019) of increasing habitat fragmentation. We found evidence for bat species-specific responses of cellular immunity between years, with neutrophil counts increasing in D. rotundus, but decreasing in S. parvidens and P. mesoamericanus from 2018 to 2019. However, the odds of infection with Bartonella spp. and hemoplasma spp. between 2017 and 2019 did not differ between bat species, contrary to our prediction that pathogen prevalence may increase with increased fragmentation. We conclude that each bat species invested differently in cellular immunity in ways that changed over years of increasing fragmentation. We recommend further research on the interactions between habitat fragmentation, cellular immunity, and infection across dietary habits of Neotropical bats for informed management and conservation.

ecology↗