Helpful insect eaters | Little brown bats can eat their body weight in insects every night
Bram Stoker has a lot to answer for when it comes to the reputation of bats as scary beasts associated with Halloween spooks.
The author of Dracula was the first to include bats in his description of Transylvanian legend, and the flying mammals have been damned by association ever since.
That is gradually changing, said University of Regina biology department head Mark Brigham.
“It’s really neat, in 23 years in Regina now, to see how kids’ attitudes have changed,” said the biologist with a keen interest in bats.
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“They won’t fly in your hair. They’re not blind. They don’t suck your blood. They’re not all vampires. Etcetera, etcetera. So it’s really neat to see that happen and I’m very pleased about that.
“I don’t think bats are perceived to be as scary as they used to be.”
Lisa Wilkinson, species-at-risk biologist with Alberta’s environment and sustainable resources department, concurs on the matter of attitudinal change.
“I just gave a presentation to a Grade 1 class and they all thought (bats) were very cute.”
There are nine species of bats in Canada and more than 1,000 in the world. All Canadian species are nocturnal insect eaters and have no reason to interact with humans, other than to use barns, sheds and trees as their homes.
Little brown bats, the most common species in parts of Alberta, can eat their body weight in insects every night, or up to 600 every hour.
“Imagine if you, as a human, could consume that much food in one night,” mused Jessica Deacon-Rogers, a technician with the Lethbridge-based Helen Schuler Nature Centre.
Navigating by sonar, bats are able to fly erratically in their pursuit of insects. That might be the cause of some human fears.
“There’s a myth about them getting caught in your hair,” said Wilkinson. “The only reason I can think that started is because they might fly around your head eating mosquitoes. They certainly don’t want to land on you.”
Bats can carry rabies, although that is rare on the Prairies. Rabid or not, both Wilkinson and Brigham cautioned against picking up bats seen on the ground because they will bite if they feel threatened.
The real threats to bats in modern times come from white nose syndrome, a fatal fungal infection, and from the proliferation of wind turbines.
White nose syndrome was accidentally introduced from Europe to a cave near Albany, New York. Since then it has steadily spread in the United States and into parts of Ontario.
Brigham said he expects white nose syndrome to attack Manitoba bats this winter or next, and continue its move westward.
“It kills somewhere between 95 and 99 percent of the individuals it affects. There’s no reason to think we’re not going to get this and we are going to notice a huge drop in the number of bats around. And there’s nothing that anyone can do about this.”
In fact, he thinks the little brown bat could eventually disappear as a result.
As for wind turbines, they are primarily a threat for the three migratory species of bats — the hoary, silver-haired and red — and then only at times of low wind speed, at dusk, during certain times of year.
“In some areas, especially closer to the foothills, there are very high mortalities of bats,” said Wilkinson.
She said biologists are working with wind turbine companies to reduce bat deaths.
Turning off the turbines for a few hours at dusk during the six-week migration period in fall could save many bat lives.
Brigham said biologists aren’t sure what attracts bats to turbines. It may be an affinity for tall structures and be related to mating instincts. Research indicates its not collision that kills bats, but rather the drastic change in air pressure created by the turbine blades.
So it appears bats have more to fear from human activity that humans do from bat activity.
“I think people are afraid (of bats) because they’re out at night, we don’t see them well, they flit around in sort of a strange way and we don’t really understand them,” said Brigham.
- Little brown bats can eat their body weight in insects each night.
- Big brown bats can eat up to 600 mosquitoes per hour.
- Bats have good eyesight and some species have better eyesight than humans.
- Bats are symbols of good luck and long life in some parts of the world.
- Bats can live 20 to 30 years.
- Bats reproduce slowly, with one baby per year.
- Females can identify their own young, probably by the sounds of their squeaks.
- Young bats can fly at three weeks of age.
- Little brown bats are the most common species in Alberta, with estimates of 1.5 million in the province.
- Colonies of little brown bats typically have 50 to 300 individuals.
- Colonies of big brown bats typically have 10 to 80 individuals.
- Hoary, silver-haired and red bats migrate in the fall. Other species hibernate.
- In Alberta, it is illegal to disturb bat hibernation sites between Sept. 1 and April 30.
- Bats are the only mammals to have achieved true flight.
- Bats do not bite, unless threatened when picked up by humans.
