Some near-extinct species such as the Great Indian Bustard should be encouraged to breed in the wild rather than in captivity, according to new research.
Captive breeding programmes offer a last resort to guard against extinction of critically endangered species, researchers said.
A new study published in the Journal of Applied Ecology shows more should be done to prevent extinction in the wild.
"Our research challenges the assumption that when a species is perilously close to extinction in the wild, it is always a good idea to set up a captive breeding population," said lead researcher Dr Paul Dolman, from University of East Anglia (UEA)'s School of Environmental Sciences.
"Captive breeding can offer a last chance when species face imminent extinction, but ultimately depends on re-establishing a population in the wild. This has proved successful for some high-profile species, but in many cases it has not," said Dolman.
"Programmes can fail for many reasons, including delays in achieving successful breeding, failure to build up a self-sustaining population, domestication and loss of genetic diversity, and poor performance after releases into the wild," said Dolman.
"Captive breeding can reduce motivation and resources for conservation in the wild, with disastrous consequences. Our research reveals the importance of objectively weighing up potential outcomes of captive breeding and comparing them with efforts to support species in the wild," said Dolman.
The study, carried out in collaboration with BirdLife International, looked at the critically endangered Great Indian Bustard (Ardeotis nigriceps).
Once widespread in peninsular India, this majestic rare bird is now restricted to a few areas - where it faces major threats from agriculture, powerlines and hunting. Numbers have declined from more than 1,000 in 1970 to as few as 100-200.
Although effective conservation in the wild has yet to be implemented, a captive breeding programme has been advocated.
Researchers used population models to evaluate the potential effectiveness of a captive-breeding and release programme compared to an alternative strategy of conservation in the wild.
"We show that only urgent and effective action to protect and extend the Great Indian Bustard's natural habitat can prevent extinction in the wild," said Dolman.
"Ten years of effective habitat conservation measures, leaving eggs in the wild and not attempting captive breeding, would result in more adults in the wild than if those eggs were harvested to set up a captive breeding population," said Dolman.
"Successful captive breeding with surplus juveniles released back into the wild would first require the collection of many wild eggs and a consistently 'best possible' performance across all aspects of the programme that would be almost impossible to achieve," Dolman added.
