Animals born in captivity have only half the odds of successful breeding compared to wild animals, scientists have revealed.
And the discovery puts into doubt the future success of animal breeding programmes which increasingly prevent the extinction of thousands of species.
Scientists found captive-born animals had, on average, almost half the odds of reproductive success compared to their wild-born counterparts in captivity.
And the effects were particularly pronounced among marine species, according to the findings published in the journal Nature Communications.
Researchers based in Australia analysed more than 100 results, from 39 animal studies of 44 diverse species including shrimp, fish, mice, ducks, lemurs and Tasmanian devils.
Study supervisor Dr Catherine Grueber, of the University of Sydney’s School of Life and Environmental Sciences and San Diego Zoo Global, said the researchers were surprised by how universal the patterns were.
She said: ‘More than 2,000 threatened species rely on successful reproduction through captive breeding programmes for conservation alone.
‘In order to maintain our food supply, it’s crucial we improve captive breeding; for example, the aquaculture industry is looking at introducing new species for commercialisation.’
Study lead author Kate Farquharson, a PhD student, said the results provide opportunities for improving the long-term success of animal breeding programmes.
‘Our dataset included measurements of lots of different reproductive traits – such as fertility, number of offspring, and timing of reproduction – but found that certain traits, such as offspring weight and mothering ability, seem to be the most strongly affected.
‘This provides an opportunity for animal breeding programmes, by identifying the areas where improvement could boost sustainability.’
Study co-author Dr Carolyn Hogg, research manager at the University of Sydney’s Australasian Wildlife Genomics Group, said the study could be extended by undertaking multi-generational studies.
Dr Hogg said: ‘Identifying limitations as well as opportunities in captive breeding programmes across all industries is an urgent priority.’
The study covered animal breeding programmes including invertebrates, fish, birds and mammals.
Across the animal kingdom, captive-born animals were found to average 42 per cent decreased odds of reproductive success, compared to those that are wild-born.
In conservation, captive breeding has been recommended by the International Union for the Conservation of Nature (IUCN) Red List assessors for 2,199 species to reduce the threat of extinction.