Genetic consequences of intensive conservation management for the Mauritius parakeet

Abstract

For conservation managers tasked with recovering threatened species, genetic structure can exacerbate the rate of loss of genetic diversity because alleles unique to a sub-population are more likely to be lost by the effects of random genetic drift than if a population is panmictic. Given that intensive management techniques commonly used to recover threatened species frequently involve movement of individuals within and between populations, managers need to be aware not only of pre-existing levels of genetic structure but also of the potential effects that intensive management might have on these patterns. The Mauritius parakeet (Psittacula echo) has been the subject of an intensive conservation programme, involving translocation and reintroduction that has recovered the population from less than 20 individuals in 1987 to approximately 500 in 2010. Analysis of genotype data derived from 18 microsatellite markers developed for this species reveals a clear signal of structure in the population before intensive management began, but which subsequently disappears following management intervention. This study illustrates the impacts that conservation management can have on the genetic structure of an island endemic population and demonstrates how translocations or reintroductions can benefit populations of endangered species by reducing the risk of loss of genetic diversity.

Micro‐evolutionary diversification among Indian Ocean parrots: temporal and spatial changes in phylogenetic diversity as a consequence of extinction and invasion

“…Psittacula echo was the world's rarest parrot in the 1980s when the total population consisted of fewer than 20 individuals prior to an intensive conservation management programme which restored the species’ wild population to over 500 individuals by 2010 (Raisin et al . , Tollington et al . ).…”

“…echo/ P. eques phylogenetic lineage. Psittacula echo was the world's rarest parrot in the 1980s when the total population consisted of fewer than 20 indi-viduals prior to an intensive conservation management programme which restored the species' wild population to over 500 individuals by 2010 (Raisin et al 2012. Establishment of populations of P. echo on Rodrigues and Reunion, by way of a conservation introduction, could therefore help to secure the short-to-medium term future of this recently restored parrot population while at the same time providing phylogenetically appropriate material for longerterm evolutionary forces to act upon to return an endemic parrot form to those islands.…”

Tracking Viral Evolution during a Disease Outbreak: the Rapid and Complete Selective Sweep of a Circovirus in the Endangered Echo Parakeet

“…Since the fixation of rep alleles occurred during an outbreak, we suggest that strong directional selection for adaptive changes was responsible rather than drift. Moreover, no significant declines have been observed in the Echo parakeet population since 1993 and analyses of the host genetic diversity using microsatellite DNA loci has not identified any significant evidence for a secondary bottleneck (49). Although changes in viral coat proteins are most commonly associated with disease outbreaks, mutations in viral replication genes have been shown to result in increased replication activity and virulence (20,53).…”

Detailed monitoring of a small but recovering population reveals sublethal effects of disease and unexpected interactions with supplemental feeding

“…; Raisin et al . ). Nevertheless, since such populations are often the focus of detailed monitoring, they can prove highly informative for refining our understanding of infectious disease.…”

“…Furthermore, recent molecular work suggests perhaps surprisingly that this species has retained relatively high levels of neutral genetic diversity despite its historic bottleneck (Raisin et al . ; Tollington et al . ).…”