Neophobic birds are less likely to adapt to rewilding

Bali mynas (Leucopsar rothschildi) are medium-sized, starling-like birds that are indigenous to Indonesia. Their striking white plumage, long crests and blue eye patches make them attractive to caged-bird enthusiasts all over the world. Sadly, the trade in these birds is one of the factors that has led to their virtual extinction in the wild. However, there are over a thousand individuals kept in zoos and bird parks, and it is hoped that these captive-bred birds will help resurrect the natural populations. 

Currently in Bali, Indonesia, there are several captive breeding programs that produce the myna birds specifically for rewilding into the areas where there are still natural populations. The remaining natural populations total only an estimated 50 birds, despite many decades of trying to bolster these populations by reintroducing captive-bred birds. Either the introductions do not cope well with life in natural surroundings, or the illegal trade in these beautiful birds is continuing unabated from within the nature reserves. 

Whatever the reason, it is critically important that those birds introduced into wild areas are strong and resourceful, and are the individuals most likely to survive the obstacles in their wild habitats. With this in mind, a team led by Dr Rachael Miller of Anglia Ruskin University (ARU) designed ways to test how 22 captive Bali mynas responded to being presented with novel objects and food items, and how well they tackled and solved simple problems. 

“We selected the Bali myna for this study specifically because they are on the brink of extinction, with fewer than 50 adults in the wild in Indonesia, but there is a captive breeding program of almost 1,000 birds in zoos around the world,” explained Dr Miller.

The study was carried out over a six-week period at three UK zoological collections – Waddesdon Manor (National Trust/ Rothschild Foundation), Cotswolds Wildlife Park and Gardens, and Birdworld, and researchers monitored the behavior of birds exposed to novel foods and other objects, along with their ability to solve simple problems. These novel items were of types likely to be encountered by myna birds in new surroundings.

The results, published in the journal Royal Society Open Science, show that neophobia (irrational fear of new objects) is a factor for some birds. Overall, birds presented with a food item took longer to touch or handle it if there was also a novel item present in the food bowl. This hesitancy was affected by age, with adult birds proving to be more neophobic than juveniles. The researchers also discovered that those birds that quickly touched familiar food that was placed beside a new object were also the quickest to solve problem-solving tasks.

The researchers believe that gathering this type of behavioral data can aid in new conservation strategies. Behavioral flexibility is crucial for an individual’s adaptability and survival, and so pre-release training and identifying specific birds for release could help with the successful reintroduction of endangered species, such as the Bali myna, into the wild.

“Neophobia can be useful in that it can help birds avoid unfamiliar dangers, but it can also impact their adaptation to new environments, such as through an increased reluctance to approach new foods,” said Dr. Miller.

“An understanding of behavioral flexibility, specifically how species and individuals within that species respond to novelty and approach new problems, is vital for conservation, particularly as the world is becoming increasingly urbanized. Many species need to adapt to human-generated environmental changes and how an animal responds to novelty can predict post-release outcomes during reintroductions.”

This new study is part of a larger project, which aims to combine avian cognition and behavior research with conservation, to help threatened species.

“As part of active conservation of the Bali myna, there is a need to continually release birds to try to boost the small, wild population. Now we have data on the behavioral flexibility of these birds, this can help to inform which birds may be best suited for reintroduction. Our study has already identified that releasing juvenile Bali myna[s] may potentially be more successful than releasing adult birds, at least in terms of adaptability to new environments,” said Dr Miller.

“Our data can also help with developing training before release, where captive birds may learn to increase fear responses to traps or people, if they were to be introduced in areas where poaching takes place, or to decrease neophobia by exposure to unfamiliar but safe food sources in areas with low resources. We believe the overall project findings will be able to help not just the Bali myna, but hopefully many other endangered species.”

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By Alison Bosman, Earth.com Staff Writer