Integrating Gut Bacterial Diversity and Captive Husbandry to Optimize Vulture Conservation.

Anne A M J Becker,Gerard Whitehouse-Tedd,Stephen W R Harrison,Katherine M Whitehouse-Tedd,Jane A Budd

doi:10.3389/fmicb.2020.01025

Abstract

Endangered species recovery plans often include captive breeding and reintroduction, but success remains rare. Critical for effective recovery is an assessment of captivity-induced changes in adaptive traits of reintroduction candidates. The gut microbiota is one such trait and is particularly important for scavengers exposed to carcass microbiomes. We investigated husbandry-associated differences in the gut microbiota of two Old World vulture species using 16S RNA gene amplicon sequencing. Increased abundance of Actinobacteria occurred when vultures were fed quail but not rat or chicken. Conversely, diet preparation (sanitization) had no effect, although bacterial diversity differed significantly between vulture species, likely reflective of evolved feeding ecologies. Whilst the relative lack of influence of a sanitized diet is encouraging, changes in bacterial abundance associated with the type of prey occurred, representing a dietary influence on host–microbiome condition warranting consideration in ex situ species recovery plans. Incorporation of microbiome research in endangered species management, therefore, provides an opportunity to refine conservation practice.

Highlights

For diverse reasons, many attempts to breed and subsequently reintroduce endangered species into their natural habitat from captivity have not been successful (Bowkett, 2009; Conde et al, 2013; Willoughby et al, 2015)
Bacterial Composition According to Vulture Species and Diet Preparation To assess sampling depth coverage and species heterogeneity in each sample, alpha diversity metrics were employed on rarefied OTU tables using observed species and Shannon’s diversity indexes
Using a threshold of 97% identity, sequences clustered into 533 OTUs with an average of 236 ± 62 OTUs retrieved in Griffon vulture samples and 180 ± 77 OTUs in Egyptian vulture samples

Summary

Introduction

Many attempts to breed and subsequently reintroduce endangered species into their natural habitat from captivity have not been successful (Bowkett, 2009; Conde et al, 2013; Willoughby et al, 2015). One potential reason is the loss of adaptive traits (Araki et al, 2007; Willoughby et al, 2015), which are encoded by the host genetic architecture and by the host-associated microbiome. The gut microbiome could be considered such an adaptive trait, representing a substantial community of microorganisms (and their collective genes) which play vital roles in host physiology (West et al, 2019) and potentially influences reintroduction success (Redford et al, 2012). The microbiome is under both genetic and environmental control, with diet acting as a pivotal determinant of gut microbial assembly (Spor et al, 2011). Animal microbiome research has only recently been introduced as a perspective for modern conservation and species recovery practices (Redford et al, 2012; Chong et al, 2019; Trevelline et al, 2019; West et al, 2019)

Objectives

Methods

Results

Conclusion