Whether it鈥檚 spotting zero or topping the charts like a condo in Creston, the BC Community Bat Program relies on its volunteer citizen scientists to commit to hours of sitting and spotting under darkening skies each spring and summer.

The data collected is critical to help understand how populations are faring across the province, said the southern Vancouver Island coordinator for the BC Community Bat Program. Plus it鈥檚 just an incredible time.

鈥淚t鈥檚 an amazing experience, staying up until the darkness sets in while counting bats,鈥� Laposa-Wilde said. 鈥淎ll your senses come alive at dusk. You hear the birds quieting down, see the light disappearing and the stars starting to shine, your skin feels the coolness of the night. All the while, you are focusing on one spot as you count the bats one by one.鈥�

Bats roost in many structures, including rocky outcrops and trees with loose bark, cracks, or cavities, but the annual count focuses on human-made structures. Most monitored roost sites 鈥� 450 sites or 45 per cent of roosts 鈥� are in occupied houses, with 395 sites or 39 per cent in bat boxes or condos.

Last year, volunteers donated 2,323 evenings over 998 bat counts. In total, 1,089 counts at 268 roost sites documented seven species in B.C. The largest colony counted in one night was a population of 3,947 at a bat condo at the Creston Valley Wildlife Management Area.

鈥淭he annual bat count involves sitting outside a bat maternity roost at sunset, and for an hour, counting all the bats that come out of that roost to forage for insects,鈥� Laposa-Wilde said. 鈥淲e usually do four bat counts at every roost site 鈥� two in June to count just the females and two more starting mid-July when the pups are learning to fly."

Started in 2012, the count is the only long-term monitoring program focused on bat summer roosts in the province. The data helps biologists monitor bat populations and track impacts to or recovery of species. In particular, they鈥檙e on the lookout for white-nose syndrome, a fungal disease that has decimated bat populations in eastern Canada and the U.S. The fungus that causes white-nose syndrome was detected in 2022 in the Grand Forks region, but white-nose syndrome itself has not been detected yet in B.C.

The count data can also illustrate general trends in populations 鈥� it's graphed by region and species to screen for sites with large declines, identify areas to focus on to improve sample sizes, and provide feedback to coordinators and volunteers. As of 2024, the majority of sites did not show declining trends.

Residents can report a bat colony or sign up to help with bat counts online at , by emailing , or calling 1-855-922-2287 ext.12.