A new Australian study has shown the first direct evidence that wing shape changes during captive breeding can cause birds to struggle to migrate once released.
This result might force conservationists to rethink how birds are kept in captivity.
“This is the first evidence that wing shape changes are a disadvantage for life in the wild,” researcher Dr Dejan Stojanovic, a conservation biologist at the Australian National University told Cosmos Science.
“The research showed that previously discovered differences in the wing shapes of captive and wild orange-bellied parrots result in an important difference in survival.”
Stojanovic is the sole researcher on the new paper, published in Ecology Letters.
Of the 16 native bird species Stojanovic looked at – including parrots, cockatiels, and finches – four of them had changes to their ‘flight feathers’ in captivity.
Flight feathers are the stiff, long feathers on the wings or tail of the bird that help with flight, and it seems even small changes to these can be a big problem.
Stojanovic found that orange-bellied parrots with the altered flight feathers have a migration survival rate 2.7 times lower than those with the ‘wild type’ wing shape.
“The species has been captive bred in a really excellent and well-resourced breeding program with multiple partners, which is why they are a great case study to look at the effects of captive breeding,” he said.
“They are one of Australia’s most endangered birds, and are unusual for a parrot that they do an arduous migration over the bass straight between Tasmania and the mainland southern coasts.
“Eighty percent of juvenile orange-bellied parrots die on their first migration, so every individual is important!”
Stojanovic says this finding does not mean that we should give up on breeding programs, as they are incredibly important part of species management but he suggests that more research needs to be done into how to fix this – potential solutions could be flight training, or genetic analysis.
“The study really highlights that it’s the quality of captive bred animals (not their quantity) that determines whether animals can survive in the wild after release.”
The research has been published in Ecology Letters.