Scientists make alarming discovery about bats: 'We still need to closely investigate and monitor'

A recent study published in Ecology Letters revealed that rising temperatures are dramatically reshaping where common noctule bats can successfully hibernate across Europe.

Scientists at the Leibniz Institute for Zoo and Wildlife Research discovered that warming winters have pushed bat hibernation areas 260 kilometers northward since 1901 (about 162 miles), with projections showing this northward expansion could continue by up to 730 kilometers (454 miles) by the century's end.

What's happening?

Research teams conducted experiments measuring how common noctule bats (small mammals weighing just 30 grams) spend their time in torpor (a hibernation state) at different temperatures. They combined these findings with daily temperature forecasts from the Potsdam Institute for Climate Impact Research to calculate energy budgets needed for winter survival across 12,000 European locations.

The model accurately reproduced historical hibernation patterns and revealed that suitable wintering grounds expanded 6.3% northeastward between 1901 and 2018. Under the most severe warming scenario — where winter temperatures could rise 2.35 degrees Celsius (4.23 degrees Fahrenheit) and hibernation seasons could be shortened by 41 days — the total northward shift could reach 990 kilometers (615 miles) over two centuries.

Why is this shift concerning?

This rapid habitat transformation threatens bat populations that rely on specific environmental conditions to survive the winter months. While these bats can physically move hundreds of kilometers in just decades, new territories may lack essential hibernation sites and adequate food sources needed before winter begins.

Bats moving northward face serious obstacles even when temperatures become suitable. These animals need specific cave structures or tree hollows for hibernation sites, and they must find enough insects to eat before winter arrives. The new regions may lack these essential resources despite having the right temperature conditions.

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Bats play crucial roles in controlling insect populations and maintaining ecosystem balance. Their forced migration could create ripple effects throughout our food chains, potentially affecting agriculture and human health as insect-borne diseases spread unchecked in areas bats abandon.

What's being done about this challenge?

Working to better understand these shifts can also enable better conservation planning, and the research team's modeling breakthrough could help simplify future monitoring efforts. They found that just two metrics — mean daily temperature during hibernation season and hibernation duration — can accurately predict suitable habitats.

"This means we could potentially map the hibernation niche of other species using the same metrics. Yet we still need to closely investigate and monitor the effects of climate change on wildlife physiology without forgetting that the environment is more than just ambient temperature," said professor Christian Voigt, head of the Leibniz-IZW Department of Evolutionary Ecology, as relayed by Phys.org.

At the community level, people can support ongoing bat conservation efforts by shopping smart, avoiding pesticides that harm their food sources, and supporting organizations working to protect wildlife habitats. These collective actions can help create healthier ecosystems that benefit both wildlife and people, proving that small changes add up to a meaningful impact for our planet's future.