Young male bats are the first of their species to adjust to the realities of a warming world, with older generations being slower to adapt.
The noctule bat (Nyctalus noctula), a common European species, traditionally migrates more than 1500 kilometres between its northern summer roosts and its southern winter hibernation grounds. Now that is changing one generation at a time, says Kseniia Kravchenko at the Leibniz Institute for Zoo and Wildlife Research in Berlin, Germany.
鈥淒ue to climate change, we have areas suitable for bats all year round, without the need to migrate for hibernation,鈥� says Kravchenko.
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The bats have a short lifespan, averaging three years, and a high reproductive rate, leading to rapid generation turnover. That means they are able to quickly shift to shorter migration distances from one generation to the next, she says, which might indicate they will cope better with global warming than other species of bats.
Colonisation of new, more northern winter hibernation areas begins with 鈥減ioneering鈥� young males, says Kravchenko. After these young males establish new winter colonies, young females and eventually older adults join them in staying closer year-round to their northern summer homes, rather than hibernating further south.
Kravchenko and her team studied nearly 3400 noctule bats in a newly colonised winter roost in Ukraine. They identified the bats鈥� summer locations from their fur using hydrogen isotopes, which originate in the animals鈥� food and water. Having followed their journeys over 12 years, the researchers determined that young males settled first in the new winter colonies further north, and that other bats joined them later.
This is good news and bad news, says Kravchenko. 鈥淭his bat species seems capable of adjusting rapidly to the high pace of climate change, which is good,鈥� she says, suggesting that this shift can help ensure its survival. 鈥淏ut what about the other species of bats that have longer generation times and don鈥檛 migrate? Global warming might be more difficult for them to cope with.鈥�
Biology Letters
