Existing conservation breeding programs inform ex-situ management options for threatened species

Abstract

As biodiversity continues to decline amid the global extinction crisis, ex-situ management, including breeding animals in captivity for release, is becoming increasingly utilised. However, these programs represent significant investments, with no guarantee of success. It is often uncertain whether a conservation breeding program could effectively contribute to species recovery. We review two large, long-term conservation breeding programs to develop a population model for the critically endangered swift parrot (Lathamus discolor). We use a population viability analysis to construct a theoretical captive breeding program to investigate the role a breeding and release program might play in delaying the current extinction trajectory. We modelled how different sized programs could supply individuals for release to supplement the wild population to generate expectations on the timeframe, release numbers, and costs involved. The modelled programs could maintain the wild population of swift parrots at low levels (< 250 birds) while releases were ongoing. After releases ceased, unabated threats would cause the wild population to sharply decline, with most simulated populations becoming extinct within 10 years if threats to the in-situ population are not mitigated. Cost estimates for these modelled programs (including releases, captive husbandry, and salaries) ranged from $54–123 million. Although releases from captivity can delay extinction and buy time to facilitate in-situ conservation efforts, they represent a significant financial investment. Ex-situ management alone cannot recover threatened populations and must be considered in conjunction with in-situ conservation efforts. Show more