Babbler birds are shifting their behavior in the wrong direction

Many animals could successfully adapt to changing environmental conditions, especially those that are flexible in their behavior. Other species, however, will not be as fortunate. 

In a new study from the University of Exeter, researchers describe how some animals fall into an “ecological trap” in the ways they respond to climate change. In particular, the experts found that chestnut-crowned babbler birds react to rising temperatures by changing their behavior in ways that could actually reduce successful breeding.

“We hope that animals that are more responsive to changes in their environment can cope better with climate change, but unfortunately they can make mistakes that make their situation even worse,” said study co-author Alex Cones.

The babblers reacted to unusually warm temperatures in early spring by breeding sooner. However, the average temperatures at this time are still colder than later in spring, which can interfere with egg incubation.

In the cold weather, the females spent less time incubating. While this may improve their own chances of survival, exposure to low temperatures is harmful to their developing eggs.

“Many animals breed as early as they can in spring, and climate change is causing this to happen earlier and earlier,” explained study co-author Professor Andy Russell.

“Paradoxically, our study shows that earlier breeding in response to warming means babbler eggs and offspring are more exposed to the cold. Babblers should respond by incubating their eggs more, but they don’t.”

Professor Russell notes that incubating eggs is more costly for the mother in terms of energy in low temperatures, so they focus on their own survival and reduce incubation.

“Parental care is adaptable, not fixed, but in this case the birds adapt in the wrong direction for their chicks’ survival – falling into an ecological ‘trap’.”

Chestnut-crowned babblers live in desert habitats across southeast Australia. Their eggs must be kept at more than 77 degrees Fahrenheit to survive, and the optimal temperature for development is about 100°F.

According to the researchers, more studies are needed to investigate whether species can successfully adapt to environmental change. However, they concluded that their findings on babbler birds are “not encouraging.”

The study is published in the Journal of Evolutionary Biology. 

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By Chrissy Sexton, Earth.com Staff Writer