Civil science suggests that NH bats may begin to recover

The sad reality is that most wildlife projects for civilian scientists are designed to quantify bad news, usually by counting the shrinking numbers of certain plants, animals or bugs that are fighting climate change and habitat loss.

So let’s celebrate the New Hampshire Bats Count project for finding what seems to be good news, even if it’s just a small part of the good news after a decade of disaster.

“There are 5 or 10 sites that have been studied over the years. 2017 was the first year that there were over 300 sites. In 2021, there were four sites over 300, ”said Sandy Houghton, a fish and game biologist. She helps oversee the annual Bat Counts project, which asks people to count bats in barns, garages and other structures where the only flying mammal likes to spend the night.

If it’s true that bat populations are growing in New Hampshire – although the limitations of civil science mean we can’t say for sure – that would be a big change. A fungal disease called white nose syndrome (WNS) has devastated bat populations across North America since it erupted in 2006, and New Hampshire is no exception.

This certainly devastated my property. We saw bats crawling on the walls of our decaying hen barn, and we could watch them move overhead in the evening, catching bugs in motion, but it’s been years since I’ve noticed more than a very rare individual fly over.

Hailey Andreosi, a wildlife conservation specialist with the UNH Cooperative Extension who also runs Bat Counts, said eight bat species are found in New Hampshire and “they are all declining in some way” either due to WNS or forest habitat loss.

The bat census project is valuable because the maternity shelters where bats raise a family in early summer are usually on private property in barns or other buildings. “We can’t know where they exist or what our bat population is, unless people tell them,” Andreozi said.

Although the number of bats cannot provide a systematic study, it can still be very useful for conservation efforts.

“We can try to see what is special in places where we see larger (populations), where bats bounce. … Is there a certain style of barn, bat box, or any feature we can try to replicate on the landscape elsewhere? ”She said.

Five species of bats migrate through New Hampshire, while three species – small brown, large brown and eastern small-legged – remain here during the winter. They usually hibernate in the mines, as the geology of New Hampshire means we don’t have much in the way of the caves. In the summer, they usually spend the night in buildings, although hopefully they don’t sneak into your attic.

Winter censuses by UNH researchers using the marking and recapture method (if you are unfamiliar with the term, you should look for it; there is some pure mathematics) have suggested that populations of these wintering bats have at least bottomed out and may to begin recovery from the WNS disaster.

“Last winter … we had a few places where we saw an individual or individuals of a species we hadn’t seen in a decade. It’s not hundreds, but it’s a small, encouraging sign, “said Houghton.

Small, really. Houghton noted that a hibernaculum, the cool term for a place where bats hibernate, has 3 small brown bats. This is a huge improvement over the zero observed in recent years – hurray! – until you find out that before WNS the number was around 2000.

So we cannot claim victory in the effort to save these important animals.

Houghton said there are some indications across the country that other populations may be recovering, although it is unclear how important this is and whether it is due to changing bat habits or the development of any resistance.

“The numbers remain low, but there are small flashes of potential hope,” Houghton said.

The Bat Census Project is inviting volunteers to observe summer bat colonies in New Hampshire, which takes about an hour and a half, starting half an hour before dusk, with at least one census in June and one in July. For more information, check the website: https://wildlife.state.nh.us/surveys/bats.html

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