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The bill of the Australian King Parakeet has been proven to grow ever larger
Photo: Tracie Louise / iStockphoto / Getty Images
The earth is heating up and it is getting hotter and hotter for its inhabitants.
While humans can sweat to cool themselves off, most animals have to do differently.
For some, the climate crisis is even affecting their appearance.
This is the result of a study published in the journal Trends in Ecology and Evolution.
According to this, it can be observed that the bodies of some animals change as a result of climate change: They get larger beaks, longer legs or larger ears in order to be able to regulate their body temperature better.
The phenomenon that the shape of animals or at least the shape of some of their body parts changes is known as
shapeshifting
.
Stuffed animals from museums serve as comparison objects
For the survey, a team led by ornithologist Sara Ryding from Deakin University in Australia examined how rising temperatures around the world affect various animal species.
In previous studies, the biologists looked for evidence that animals change their shape as a result of warming.
And found several scientific examples, especially in the bird world.
The change can be shown, for example, by comparing stuffed representatives of a species from museums with specimens living today.
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Some of this work showed, for example, that the beak size of several Australian parrot species has increased by an average of four to ten percent since 1871.
This growth correlates with the increase in the annual summer temperature.
A similar development can be seen in the North American winter bunting: there is a connection between the increase in beak size and short-term temperature extremes in cold surroundings.
Changes were also observed in mammals: For example, researchers reported an increase in tail length in wood mice and an increase in tail and leg size in American masked red-toothed shrews.
The only thing they have in common is climate change
"The increase in limb size observed so far is less than ten percent, so the changes are unlikely to be noticeable immediately," said Ryding, the study's lead author.
"However, protruding parts of the body like the ears are expected to get bigger - so we might see a Dumbo in action in the not too distant future."
Overall, climate change is a complex and multi-layered phenomenon that is taking place gradually.
It is therefore difficult to name only one cause for the change in shape of the animals.
However, the changes can be observed in numerous geographical regions and in a large number of species - apart from climate change, there is little in common.
What use are the changes?
But what use is a larger beak or a longer tail to animals? In biology there is the so-called »Allen's rule«. This rule describes that animals from cold regions often have smaller limbs, tails and ears than closely related species from warmer regions. Because: Smaller limbs form a smaller body surface through which heat can be lost. And analogously, a large body surface allows excess body heat to be dissipated more easily. Beaks that are not covered by feathers and are therefore not insulated are an important place for heat exchange, as are the ears, tails, and legs of mammals that do not grow fur.
African elephants and donkey hares, for example, pump as much blood as possible into their large ears at high temperatures, which they then cool down by waving.
The giant toucan uses its huge beak as a built-in cooling system: in the cooler evening hours, it dissipates excess heat to the environment via its beak.
The fact that some animals apparently adapt to warm temperatures does not mean that they can permanently defy the climate crisis.
It is high time to acknowledge that animals also have to adapt to the climatic changes - and indeed in a very short time frame in terms of evolutionary history, said Ryding.
"The climate change we are causing is putting tremendous pressure on them, and while some species will adapt, others will not."
vki / dpa
