Waterloo Region a hangout for migrating bat species
But UW graduate’s study finds numbers are low in six local urban forests
WATERLOO REGION — Bats are having a hard time right now.
Not only are they considered the source of the SARS COVID-19 virus, but bat populations in North America are plummeting.
Three bat species out of Ontario’s eight have lost 90 per cent of their populations. Four of Ontario’s bat species are listed as endangered and three more are under review for potential listing.
Ontario’s bats can be categorized into two main groups: those who migrate south to the United States or South America for the winter, and those who stay relatively close and hibernate.
Both types are in trouble. Those that migrate to warmer areas for the winter are being decimated by wind turbines — about 500,000 a year across North America.
The bats that stay to hibernate have died by the millions across North America over the past 15 years because of white nose syndrome.
Waterloo Region sits in the middle of flight paths as hibernating bats move further north to find their hibernacula — a very vampire-y way to say the place where they hibernate for the winter — or migrating bats move down south.
This means the forests in Waterloo Region’s cities can act as stopover sites for many of Ontario’s bat species.
Hannah Adams is a recent environmental science graduate at the University of Waterloo. She completed her undergraduate thesis on how bat populations use the forested spaces within the region’s urban areas during migration. She wanted to know what bats look for in stopover sites.
She chose six urban forests that varied in size, shape and connectivity with other natural areas, including Grey Silo golf course, Columbia Lake, Bechtel Park, Stanley Park, Huron Natural Area and Woodside National Historic Site. Adams set up microphones at all six sites. Between August and November last year, she recorded bat activity during the night and analyzed the recordings to understand bat activity in the area.
She confirmed that bat populations are low. Extremely low. Only six of Ontario’s eight species were detected, and of those only two were detected in high enough numbers to analyze including the silver-haired bat and the big brown bat.
She was surprised to find that bats don’t necessarily need connected forests. She found that bats are attracted to forests both larger and with more irregular shapes because they offer more “edge” habitat where they can forage for insects.
Woodside National Historic Site had the least bat activity, while Huron Natural Area had the most, which makes sense because it has the most perimeter, or edge habitat of the areas studied.
Adams’ biggest take-away from her research is that Waterloo Region’s urban forests act as important stopover sites for bats by offering roosting and foraging opportunities that can’t be found in agricultural areas.
Even the most degraded urban woodlots are important for bats, she says.
“My results suggest that degraded urban areas are still important for maintaining connectivity in the landscape for migratory and resident bat species,” she writes in her article.
While bat populations have plummeted across North America, some pocket populations seem to be able to persist or even rebound despite white nose syndrome, says Liam McGuire, an associate professor in biology who studies bats at the University of Waterloo. McGuire supervised Adams for her thesis research.
“The focus is now how can we support the bats that are still here,” says McGuire.
McGuire is one of a few bat researchers in Waterloo Region and part of a larger community of researchers from many disciplines across Canada and North America studying white nose syndrome and trying to help bat populations rebound.
The key, says McGuire, is to ensure bats have plentiful opportunities to forage, because they rely on their fat stores to survive throughout the winter.
White nose syndrome is caused by a fungus called Pseudogymnoascus destructans, or Pd, that grows in cold damp places. It attacks bats while they are hibernating and causes them to become more active than usual. This burns up their fat stores which they need to survive the winter.