Uropygial gland microbiota differ between free-living and captive songbirds

Abstract

Symbiotic microbes can affect host behavior and fitness. Gut microbiota have received the most study, with less attention to other important microbial communities like those of scent-producing glands such as mammalian anal glands and the avian uropygial gland. However, mounting evidence suggests that microbes inhabiting scent-producing glands play an important role in animal behavior by contributing to variation in chemical signals. Free-living and captive conditions typically differ in social environment, food diversity and availability, disease exposure, and other factors—all of which can translate into differences in gut microbiota. However, whether extrinsic factors such as captivity alter microbial communities in scent glands remains an open question. We compared the uropygial gland microbiota of free-living and captive song sparrows (Melospiza melodia) and tested for an effect of dietary manipulations on the gland microbiota of captive birds. As predicted, the uropygial gland microbiota was significantly different between free-living and captive birds. Surprisingly, microbial diversity was higher in captive than free-living birds, and we found no effect of dietary treatments on captive bird microbiota. Identifying the specific factors responsible for microbial differences among groups and determining whether changes in symbiotic microbiota alter behavior and fitness are important next steps in this field.

Comparison of gut microbiota between immigrant and native populations of the Silver-eared Mesia (Leiothrix argentauris) living in mining area

“…This is the first study to show the gut microbiota of Silver-eared Mesia whose habitat has been altered by trade. Previous studies have focused on comparing native habitats with captivity ( Wienemann et al, 2011 ; Sun et al, 2019 ; Oliveira et al, 2020 ; San Juan et al, 2021 ; Grieves et al, 2022 ; Zhang et al, 2022 ). However, under captive conditions, the host’s living environment and diet are artificially controlled, so it is difficult to reflect the impact of the real field environment on the intestinal microbiota of immigrant species.…”