Local, Environmental and Trace Metal Effects on Gut Microbiota Diversity in Urban Feral Pigeons

Abstract

Nowadays, understanding the biotic responses to the enhanced urbanization need to encompass not the only the physiological and phenotypic features but also the related microbiota of wildlife animals. One of main threats in urban ecosystems is the chemical pollution. Thus, we have explored whether the cloacal microbiota of feral pigeons (Columba livia) are impacted by both their geographical foraging area, and TE exposure in an urban context. First, pigeons were captured in 4 specific areas of Paris (France) and placed in captivity. By applying a 16SrRNA metabarcoding approach, we observed that the gut microbiota diversity was structuring according to the capture sites. Subsequently, we experimentally exposed to zinc and/or lead (two-factor cross design) during 90 days in a non-urban environment, and we observed that the metal exposure did not affect the composition and diversity of pigeon gut microbiota, during the whole experiment. However, this diversity and composition significantly differed from the microbiota observed at the capture period, suggesting a strong and rapid impact of the lifestyles (captivity in non-urban environment) on the gut microbiota. Our finding shed light on the effects of urban pollution and environment on bird communities, that can be extended to their gut microbiota causing potential dysbiosis and may thus produce additive or synergic negative effects to host organisms and populations.

Keywords: cloacal microbiota, urban ecology, captivity, chemical pollution