Birds must adapt to climate change, but evolution is a slow process. Model species such as the great tit are an essential benchmark in our ability to predict the impact of climate change on nature. Using new methods, a team from the Netherlands Institute of Ecology (NIOO-KNAW) investigated the future of birds.
Can species adapt to climate change in the future? How fast can they adapt? We need to understand this before we can properly predict the effects of climate change on the environment as a whole. “It is important to know,” emphasizes research leader Marcel Visser, “because climate change and evolution must continue at a relatively similar pace to maintain species.”
Back to the future
“So we started studying big tits from the future,” explained Visser. “In the coming decades, natural selection will produce birds with a particular genetic make-up. To predict the extent to which these birds will respond to natural selection, we speed up evolution by artificially selecting genetically early and late birds in aviaries. We then brought the eggs of our long-term population to De Hoge Veluwe national park, to see how their offspring fared compared to wild big breasts.”
“In the wild, the earliest birds actually lay eggs earlier than the big tits that are selected to lay eggs later,” added researcher Melanie Lindner. “So we were able to successfully select them for laying eggs early or late spring. But the earliest birds did not lay eggs much earlier than the wild big tits breeding in the forest, while our selection for to lay eggs later. , have a much later resting date.”
In the end, these early birds were less successful than the birds of the forest. “The genetic adaptation to an early lay date has been an extremely slow process.” The results of the study were published in the journal Advances in Sciencewith Lindner as first author.
Ecological relationship problems
Climate change is giving insectivorous songbirds like the great tit a bad case of ecological problems. Their timing no longer coincides with that of the insects that feed their young: the “caterpillar peak” in the forest and the moment when the young big breasts hatch no longer coincide. Because of this, they miss out on the biggest, juiciest caterpillars —which contain the most nutritious proteins. Changing their time may be a solution, but so far it remains unclear how early the birds can lay eggs.
So what will happen to big tits in the coming decade? “What we see now is that climate change is too easy for them,” says Marcel Visser. “They are not able to adapt enough. In the worst climate scenarios, in particular, the birds will fall behind more and more.” As a result, the number of large tits fledging will decrease.
Camouflage
So why are we not witnessing a decline in the population of the big tit at the moment? “Today, population effects are buffered by density-dependent processes,” says Visser. The true impact of climate change is currently ‘camouflaged’: out of every ten chicks, eight or nine usually die in the first year as a result of predation, disease, food scarcity, competition or bad luck. . But if three of them die before fleeing due to climate change, the chances of the remaining seven will improve. There’s plenty of food to go around, and quite a bit of competition. “But there is a limit.”
“There is also a big difference from year to year in terms of weather, which makes it more difficult to measure the impact of birds on the farm. In the years of the study, the mismatch between the wild big tits and their food—the moth larvae in winter—happen to be surprisingly few.”
So what else do we need to know? Visser has some suggestions: “Now that we’re looking at the impact of climate change on the fairly straightforward food chain of the oak tree, the winter moth and the great tit, it’s time to see if can we include a larger number of species that produce in common. in a food network. Like for example the whole Veluwe.”
That’s exactly one of the goals of the great LTER-LIFE program, which is about to start this July: Developing ‘digital twins’ of ecosystems to help predict how global change will affect the environment. And the natural area of Veluwe is the first case.
More information:
Melanie Lindner et al, Genotypes selected for early and late bird laying dates differ in their phenotype, but not fitness, in the wild, Advances in Science (2023). DOI: 10.1126/sciadv.ade6350
Provided by the Netherlands Institute of Ecology
Citation: Researchers examine how birds respond to natural selection to adapt to climate change (2023, June 30) retrieved July 4, 2023 from https://phys.org/news/2023- 06-birds-natural-pace-climate.html
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