Pilot study suggests cellular immunity changes in bats from urban landscapes

Abstract

Abstract Environmental pollution and habitat loss and are influencing the health status of wild animals and increase the risk of zoonosis outbreaks. For example, the ongoing urbanisation leads to significant habitat changes and burden of anthropogenic stressors. Bats are a diverse mammalian order occurring in urban areas. In a pilot study, we investigated the general immunity status of two common bat species along urban-natural gradients. We used haematological parameters as cellular immunity indicators and intensity of light pollution as a proxy for urbanisation level (i.e. anthropogenic stress) at the sampling points. We found higher total white blood cell, lymphocytes and neutrophil proportions in Nyctalus noctula from suburban and urban habitats in comparison to those from natural ones. At the same time Eptesicus serotinus, a species commonly living in cities, had a lower neutrophil level and a trend towards lower neutrophil-to-lymphocyte ratio and intoxication index compared to N. noctula which only uses the suburban-urban area seasonally. Our study suggests that the cellular immunity in bats is altered by urban stressors, yet depends on species-specific tolerance. We call for more research in this area and, as precaution principle, conservation of habitats in urban areas in order to mitigate the negative impact of urban stressors on the health of wildlife.