Flying squirrels featured at Norfolk Field Naturalists’ talk

A northern flying squirrel climbs a tree at a Kawartha Highlands field site. Fur- covered membranes between the front and hind legs allow flying squirrels to travel between trees by gliding through the air. 

Lisa Timpf

Advocate Contributor

In his role with the Ministry of Natural Resources, research scientist Jeff Bowman has worked with many different species, including lynx, mink, and bats. But flying squirrels have always been near and dear to his heart.

Bowman was the featured presenter at the Norfolk Field Naturalists’ April speaker event, where he shared some of his research findings in relation to Ontario’s flying squirrels.

Bowman, who is also an adjunct professor at Trent University in Peterborough, began working with flying squirrels in 2001. At the time, flying squirrels were a species of special concern. Bowman surveyed flying squirrel populations and gathered data. Twenty-plus years later, he’s still learning new things about them.

North America boasts three species of flying squirrels, two of which - the southern flying squirrel and the northern flying squirrel - can be found in Ontario.

Despite their name, flying squirrels don’t really ‘fly.’ Unlike birds and bats, they don’t have wings. Instead, they have fur-covered membranes that run between the front and back legs, creating a parachute-like effect when they take to the air. This allows flying squirrels to travel between trees by gliding.

Even this talent is pretty impressive. For each metre of height they descend, flying squirrels can travel three times as far in distance. For example, in a 10-metre drop a flying squirrel can glide for 30 metres. The squirrels can also adjust their travel direction while gliding.

Here in Norfolk County, we are most likely to encounter the southern flying squirrel, which likes temperate forests. Populations have been found in Backus Woods and along the north shore of Lake Erie. Some NFN members noted that they have had flying squirrels on their properties. Because flying squirrels are nocturnal, many people are unaware of their presence.

Northern flying squirrels prefer northern older-growth coniferous forests, where they dine on lichen, fungus, and truffles, among other woodland delicacies. Bowman notes that northern flying squirrels play a critical role in the ecosystem, by helping to spread fungal spores, which in turn benefits tree populations.

Bowman’s research revealed that as winter temperatures have trended warmer, the southern flying squirrel has expended its range northward, sometimes hybridizing with their northern neighbours. However, severely cold winters, when they occur, provide setbacks to the southern squirrels’ expansion plans.

Southern flying squirrels have a tough time maintaining body temperature in winter. They ride out the cold by huddling with nest-mates in tree cavities. Nest-mates are not squirrels who are related, but rather those whose foraging ranges overlap. Squirrels who are ‘neighbours’ will share winter nest sites in subsequent years, with researchers finding as many as 23 hunkering down in the same nest site during the coldest months.

What the squirrels don’t share, however, is food. Each flying squirrel has its own food caches, painstakingly built up over the warmer months. When it’s time to forage, the squirrels travel off individually, guided to their cache sites by spatial memory.

Studying a nocturnal species comes with challenges. Bowman explained the various ways technical aids like microchipping and radio frequency tag readers help researchers collect data. All Bowman’s research, whether done through the Ministry of Natural Resources or Trent University, is governed by animal welfare standards, and steps are taken to minimize any potential discomfort to the squirrels.

Research has also shown that the fur of the flying squirrel is fluorescent under black light, with the intensity of the colour varying depending on where the squirrel is in its moulting cycle, and the age of the squirrel. The spectacular effect of the fluorescence has been captured in video footage, creating an almost eerie effect. Bowman notes that researchers don’t know for sure whether the squirrels themselves can see the phenomenon.

Flying squirrels also make a number of vocal sounds to communicate information such as which nest tree they are using on a given night. Much of this communication takes place in an ultrasound frequency that is out of the hearing range of owls, which are one of the flying squirrels’ predators.

Bowman isn’t the only person who finds flying squirrels intriguing. Squirrels in his research areas have been featured in documentaries, news stories, and videos, with flying squirrel footage appearing on CHEX News, Discovery Channel, TVO and other venues.

Though his initial research into flying squirrels was sparked by a follow-up on their ‘special concern’ status, Bowman reports that as of now, the squirrels are no longer listed as a species of concern.

Like many other Norfolk Field Naturalists talks, the ‘Flying Squirrels of Ontario’ presentation highlighted the fascinating complexity of our province’s ecosystems and the intriguing plants and animals that inhabit them. 

Bowman’s talk was NFN’s final speaker event of the spring season. Speaker events will resume in September. However, several field events are planned in the coming months, including Spring Birding in Backus Woods, an Ephemeral Wildflower Hike, and a Mother’s Day Spring Wildflower Hike. 

Pre-registration is required for some events. Information is available on the NFN website, norfolkfieldnaturalists.org.