Animals adapt to climate heat, but too slowly

Great tits are among the species which show an ability to adapt. Image: By Martin Arusalu on Unsplash

Can animals adapt to climate change? And if so, can species adapt fast enough to ensure survival? Reports so far are not promising.

LONDON, 5 August, 2019 − German scientists have an answer to the great question of species survival: can animals adapt to climate change? The answer, based on close analysis of 10,000 studies, is a simple one. They may be able to adapt, but not fast enough.

The question is a serious one. Earth is home to many millions of species that have evolved – and adapted or gone extinct – with successive dramatic shifts in climate over the last 500 million years.

The rapid heating of the planet in a climate emergency driven by profligate fossil fuel use threatens a measurable shift in climate conditions and is in any case coincident with what looks like the beginning of a mass extinction that could match any recorded in the rocks of the Permian, or other extinctions linked with global climate change.

The difference is that climate is now changing at a rate far faster than any previous episode. So can those animals that cannot migrate to cooler climates adjust to changing conditions?

“Even populations undergoing adaptive change do so at a pace that does not guarantee their persistence”

A team from the Leibniz Institute for Zoo and Wildlife Research in Berlin and more than 60 colleagues from around the world report in the journal Nature Communications that they examined whether creatures could change either their physiology, size or behaviour to accommodate a rise in temperature accompanied by a change in the timing of the seasons. Biologists call this kind of response “phenotypic change.”

Questions like these are not easily answered. To be sure, the biologists needed reliable local records of temperatures across a number of locations. Then they needed sure information about the timing of migration, reproduction, hibernation and other big events in the lives of their subjects over a number of years.

And then they needed to find case studies where data had been collected over many generations in one population of creatures in one space.

And having found changes in the traits of their selected creatures, the biologists had to work out whether such changes led to higher levels of survival, or more offspring. They found reliable information about 17 species in 13 countries.

Pessimism alert

In the end, most of their data came from studies of birds, among them common and abundant species such as the great tit Parus major, the common magpie Pica pica or the European pied flycatcher Ficedula hypoleuca.

The message is that even if bird populations can change with their environmental conditions, they may not be able to do so at the speed necessary to time migrations to coincide with ever-earlier spring flowering, or nesting to match the explosion of insect populations that provide food for nestlings.

“Even populations undergoing adaptive change do so at a pace that does not guarantee their persistence,” said Alexandre Courtiol of the Leibniz Institute. And the data available apply to species that are known to cope relatively well with changing conditions.

“Adaptive responses among rare or endangered species remain to be analysed,” said his colleague and co-author Stephanie Kramer-Schadt, a Liebniz ecologist. “We fear that the forecasts of population persistence for such species of conservation concern will be even more pessimistic.” − Climate News Network