Fine-scale distribution modeling of avian malaria vectors in north-central Kansas.

Abstract

Infectious diseases increasingly play a role in the decline of wildlife populations. Vector-borne diseases, in particular, have been implicated in mass mortality events and localized population declines are threatening some species with extinction. Transmission patterns for vector-borne diseases are influenced by the spatial distribution of vectors and are therefore not uniform across the landscape. Avian malaria is a globally distributed vector-borne disease that has been shown to affect endemic bird populations of North America. We evaluated shared habitat use between avian malaria vectors, mosquitoes in the genus Culex and a native grassland bird, the Greater Prairie-Chicken (Tympanuchus cupido), by (1) modeling the distribution of Culex spp. occurrence across the Smoky Hills of north-central Kansas using detection data and habitat variables, (2) assessing the occurrence of these vectors at nests of female Greater Prairie-Chickens, and (3) evaluating if shared habitat use between vectors and hosts is correlated with malarial infection status of the Greater Prairie-Chicken. Our results indicate that Culex occurrence increased at nest locations compared to other available but unoccupied grassland habitats; however the shared habitat use between vectors and hosts did not result in an increased prevalence of malarial parasites in Greater Prairie-Chickens that occupied habitats with high vector occurrence. We developed a predictive map to illustrate the associations between Culex occurrence and infection status with malarial parasites in an obligate grassland bird that may be used to guide management decisions to limit the spread of vector-borne diseases.