Inbreeding depression in one of the last DFTD-free wild populations of Tasmanian devils.

Rebecca M Gooley,Carolyn J Hogg,David Pemberton,Samantha Fox,Catherine E Grueber,Katherine Belov

doi:10.7717/peerj.9220

Rebecca M Gooley, Carolyn J Hogg + Show 4 more

Open Access

https://doi.org/10.7717/peerj.9220

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Journal: PeerJ	Publication Date: Jun 16, 2020
Citations: 5	License type: CC BY 4.0

Affiliation: University of Sydney

Abstract

BackgroundVulnerable species experiencing inbreeding depression are prone to localised extinctions because of their reduced fitness. For Tasmanian devils, the rapid spread of devil facial tumour disease (DFTD) has led to population declines and fragmentation across the species’ range. Here we show that one of the few remaining DFTD-free populations of Tasmanian devils is experiencing inbreeding depression. Moreover, this population has experienced a significant reduction in reproductive success over recent years.MethodsWe used 32 microsatellite loci to examine changes in genetic diversity and inbreeding in the wild population at Woolnorth, alongside field data on breeding success from females to test for inbreeding depression.ResultsWefound that maternal internal relatedness has a negative impact on litter sizes. The results of this study imply that this population may be entering an extinction vortex and that to protect the population genetic rescue should be considered. This study provides conservation managers with useful information for managing wild devils and provides support for the “Wild Devil Recovery Program”, which is currently augmenting small, isolated populations.

Highlights

For threatened species, a reduction in reproductive success can severely impact population persistence
The Tasmanian devil, Sarcophilus harrisii, is one such species that has declined up to 80% in areas affected by an infectious clonal cancer, devil facial tumour disease (DFTD) (Loh et al, 2006; Pye et al, 2016; Lazenby et al, 2018)
Samples were collected by the Save the Tasmanian Devil Program (STDP) following their Standard Operating Procedure and shared with the University of Sydney for genetic analysis

Summary

Introduction

A reduction in reproductive success can severely impact population persistence. The Tasmanian devil, Sarcophilus harrisii, is one such species that has declined up to 80% in areas affected by an infectious clonal cancer, devil facial tumour disease (DFTD) (Loh et al, 2006; Pye et al, 2016; Lazenby et al, 2018). Inbreeding depression in one of the last DFTD-free wild populations of Tasmanian devils. For Tasmanian devils, the rapid spread of devil facial tumour disease (DFTD) has led to population declines and fragmentation across the species’ range. We show that one of the few remaining DFTD-free populations of Tasmanian devils is experiencing inbreeding depression. This population has experienced a significant reduction in reproductive success over recent years. This study provides conservation managers with useful information for managing wild devils and provides support for the ‘‘Wild Devil Recovery Program’’, which is currently augmenting small, isolated populations

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