Climate change drives Babbler birds into “ecological trap”

Babbler with chest crown. Credit: Niall Stopford

Animals can fall into an “ecological trap” by changing their behavior in the “wrong way” in response to climate change, researchers say.

The so-called “rescue hypothesis” suggests that many species may adapt to changing conditions, especially those that are flexible in their behavior.

But a new study, by the University of Exeter, found that birds of a breastfeed baby responded to rising temperatures by changing their behavior in ways that could reduce successful breeding.

This was due to the fact that they responded to warm temperatures in early spring by breeding earlier – but the average temperature at this time is still colder than later in the spring, which is bad for stimulating eggs.

Instead of spending more time incubating, females responded to the cold by introducing less – which may improve their own chances of survival but which reveals the eggs hatched. grows to a harmful, low temperature.

“We hope that animals that are more adaptable to changes in their environment can better cope with climate change, but unfortunately they can make mistakes that will make the situation worse,” said Alex Cones. who worked on this research during her masters at the University of Exeter.

Professor Andy Russell, from the Center for Ecology and Conservation at the Penryn Exeter Campus in Cornwall, said: “Many animals breed as early as possible in the spring, and climate change is taking place. cause this to happen earlier and earlier.

“Surprisingly, our study shows that earlier breeding in response to warming means that babies’ and children’s eggs are more exposed to the cold.

“Babies should respond by adding more of their eggs, but they don’t.

“Hatching eggs is more expensive for the mother in terms of energy at low temperatures, so they aim for their own survival and reduce hatching.”

Dr Russell said: “Parental care is flexible, it’s not fixed, but in this case the birds change in the wrong direction to keep their chicks alive – falling. in an ecological ‘trap’. ”

Babies with a walnut crown live in desert habitats in southeastern Australia.

Their eggs need to be kept at more than 25 ° C (77 ° F) to survive, and development occurs best and fastest at around 38 ° C (100 ° F).

The researchers say more studies are needed to find out if “plastic” (flexible) parenting could provide an “evolutionary rescue package” to protect species from environmental change.

However, they conclude that the evidence from this study is not “encouraging”. ”

Fact: “Medium-temperature plasticity in stimulus plates does not appear to protect embryos from climate challenge in seasonal songbirds” by Alexandra G. Cones, Andrea L. Liebl, Thomas M. Houslay and Andrew F. Russell, 16 December 2020, Journal of Evolutionary Biology.
DOI: 10.1111 / jeb.13743

The study was funded by the Natural Environment Monitoring Council (NERC).

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