Comparing western (Megascops kennicottii) and whiskered (M. trichopsis) screech-owl microbiomes in southern Arizona using a novel 16S rRNA sequencing method

Abstract

Microbiomes are essential to a host’s physiology and health. Despite the overall importance of microbiomes to animal health, they remain understudied in wildlife. Microbiomes function as physical barriers to invading pathogens, and changes in the diversity or composition of microbes within a host may disrupt this barrier. In order to use microbiomes in wildlife ecology, knowledge of the natural variation within and among species is essential. We compare the diversity and composition of two avian species that share the same habitat and niche in our study area, the western screech-owl (Megascops kennicottii) and the whiskered screech-owl (M. trichopsis). We used a targeted 16S sequencing method to improve the taxonomic resolution of microbiomes. We found similar measures of alpha diversity between species and sample types (cloacal samples vs. fecal samples). However, there were significant differences in bacterial species richness among nestlings from different nest boxes, and the composition differed between the two bird species and among nestlings from different nest boxes. Western screech-owls had more variation in alpha diversity and composition and had fewer bacterial species in their core microbiome than whiskered screech-owls. Siblings are likely to yield similar findings for microbiomes; thus, sampling nestlings from different nests may be most informative for monitoring population-level changes.

Stopover habitat selection drives variation in the gut microbiome composition and pathogen acquisition by migrating shorebirds

“…Similar effect of host taxonomy on the composition of gut microbiota was reported in a wide range of other avian lineages, including ducks, owls, penguins, and passerines (Dewar et al 2013 , Bodawatta et al. 2018 , Hird et al 2018 , Maraci et al 2021 , Bartlow et al 2022 ). In many cases, differences in the gut microbiota were still apparent despite sympatric occurrence and similar habitat types used by different species (Yang et al 2016 , Cho and Lee 2020 , Lu et al 2022 but see Grond et al 2019 ), which is consistent with our results.…”

“…So far, age-related differences in the gut microbiota were detected in various bird species, but the majority of studies were based on comparisons between nestlings and adult birds (van Dongen et al 2013 , Barbosa et al 2016 , Bartlow et al 2022 ). In general, bacterial community in chicks is often less abundant and more temporarily unstable than in adult individuals (Sun et al 2022 ).…”

Use of nest boxes, reproductive success, and sex ratio in two screech-owls in the Peloncillo Mountains of southeastern Arizona

“…This study was completed during the breeding seasons of 2015–2022 and was conducted in Miller Creek Canyon in the Peloncillo Mountains in southeastern AZ, near the borders of NM and Mexico (31.4818°N, –109.0545°W, WGS 84; see site map in Bartlow et al 2022). This area has a diverse vegetative community dominated by an oak ( Quercus spp.)…”