Spatial Variation in the Inflammatory Response of House Sparrows in their Native Range.

Characterizing spatial differences in wildlife immunity is the first step to identify environmental drivers of host defense and disease risks. The house sparrow (Passer domesticus) is a model system for ecoimmunology, but spatial differences in immunity have been largely restricted to the invasive range of this global species. We provide an initial test of spatial variation in immune response to phytohemagglutinin in the native range, finding that birds from Romania have greater inflammatory responses than birds from Egypt. Future broad surveys across the house sparrow native range could contextualize these differences and determine underlying drivers.