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Ravens, Owls and Bats — Oh My! Wildlife facts from the Department of Biology

Great Gray Owl - Copyright Michael Runtz, Carleton University 

In the spirit of Halloween, we’re sharing fascinating facts about spooktacular creatures.

Read on to learn about owls, bats, ravens, wolves and spiders from Michael Runtz, an instructor in Carleton’s Department of Biology and one of Canada’s foremost naturalists, nature photographers and natural history authors.

Along the way, discover wildlife research taking place at Carleton, like that of recent M.Sc. graduates Lauren Moretto and Julia Put, who conducted research on bats in the Fahrig Lab.

Happy Halloween from the Faculty of Science!


OWLS

Silent Hunters with Rotating Heads and Reversible Toes

Barred Owl - Copyright Michael Runtz, Carleton University

Did you know?

  • They use their faces to hear. Feathers that form discs around their eyes act like satellite dishes to capture sound and direct it back down to the ear openings on either side of their heads.

  • They have auditory crosshairs. Wide heads and asymmetrical ear canals allow them to tell precisely where a sound is coming from, up to three-millionths of a second.

  • They have completely silent flight. Their wings and feathers have silencers – soft, fringed edges – that break up the air. Their feathers also have a soft pile, unlike fast flying birds like hawks or falcons, which have hard feathers for thrust.

  • They can turn their heads 270 degrees. Owl neck vertebrae are ten times larger than the blood vessels that run through them. They also have large pools of blood they can draw from, so that if they happen to pinch off blood vessels while turning their heads, they can continue to get blood to the brain.  

  • They have one reversible toe on each foot, which helps them to grab things.


BATS 

Busy Eating Their Weight in Insects

Big Brown Bat - Copyright Michael Runtz, Carleton University

Did you know?

  • They are the only mammal that truly flies.

  • They can consume the equivalent of their body weight in insects in a night.

  • They use echo-location to find their prey; the first frequency of sound they use is for surveying the area, and when they hit something of interest, they can modulate the frequency to create faster pulse rates, giving them a finer picture of what’s there.

  • In winter, bats go dormant, but once they give birth in spring, the females spend their time together in a maternity roost while the males roost separately.

  • They help to make tequila in Mexico by pollinating agave flowers, thereby increasing genetic diversity among agave plants. Bat biologists in Mexico are working with agave farmers to promote healthy crops in this way.

  • Tip: Shake your car keys above your head and a bat may just swoop down to check you out!

Interested in wildlife research at Carleton University? Two recent master’s graduates tell us about the research they conducted on bats in the Fahrig Lab

Julia Put's research on bats during her M.Sc. at Carleton University

“My M.Sc. research in the Fahrig Lab used acoustic recorders and insect traps to compare bat activity and bat prey availability at organic vs. conventional agricultural fields. We matched organic-conventional pairs of fields such that in each pair the fields were similar in size, hedgerow length, and surrounding landscape composition. We found that organic fields had greater bat activity and bat prey availability than conventional fields.”

– Julia Put, M.Sc., Carleton University

Lauren Moretto Lauren's research on bats during her M.Sc. at Carleton University

“My research aims to inform effective management of bat habitat in urban environments, since urbanization is increasingly impacting wildlife. Specifically, I aimed to find how far away in Toronto bat activity is impacted by the addition or loss of tree canopy, which was about 200m. In other words, if we chopped down or planted trees in a backyard or park, it would influence bat activity about 200m away.”

– Lauren Moretto, B.Sc., M.Sc., Geomatics and Landscape Ecology Research Laboratory (GLEL), Carleton University


RAVENS

Problem Solvers with Puzzling Vocals

Common Raven - Copyright Michael Runtz, Carleton University

Did you know?

  • They were extremely rare in Ottawa fifty years ago but now commonly nest in the city, often on Carleton’s campus.

  • They are part of a group called corvids and are known to be one of the smartest birds in the world for problem solving.

  • In winter, young ravens like to gather around animal carcasses, where they'll scream and draw more young ravens in. During the weeks they spend together, they will have courtship and pair up for the next year.

  • They have really diverse vocalizations – bells and screams – that often puzzle people.

  • They have bristle-like feathers on their bills that serve as dust-busters, keeping garbage out and warm air in.

Common Raven - Copyright Michael Runtz, Carleton University


WOLVES

It’s Their Pack and They’ll Howl if They Want To

Eastern Wolf howling 2.jpg

Did you know?

  • They don’t howl at the moon – that’s a myth – but they do howl for communication.

  • They use howling as a spacing mechanism. Packs maintain territories and howling defines the territorial boundaries to keep other wolves out.

  • The whole pack of adult wolves takes care of the pups. In summertime, the pups are left at rendezvous sites while the adults go hunting, but one adult stays close enough to hear the pups in case there is trouble and they need to return to defend them. 

  • Pups bite at the corners of an adult wolf's mouth, who then regurgitates food for the pup. 

Would you like to howl with the wolves?

Join Michael Runtz, a Carleton Biology instructor and a renowned Canadian naturalist, at a Wolf Howl in August.

For the past 25 years, Runtz has led the Wolf Howl at Bonnechere Provincial Park, which saw over 275 attendees in 2018. He also leads an annual Public Wolf Howl at Algonquin Provincial Park. 

Eastern Wolf pups howling_.jpg


SPIDERS

Oh, The Webs They Weave – in Just 20 Minutes!

Jumping Spider_.jpg

Did you know?

  • They recycle their broken webs by eating them and then creating new silk.

  • They can build huge webs – complex orb webs with circular patterns – in just 20 minutes.

  • They have seven different kinds of silk; some are sticky and some are stretchy. If silk dries out, it becomes brittle, so to build webs they use silk that absorbs moisture from the air. This explains why, at daybreak, spider webs are covered in dew drops!

  • They have eight eyes and eight legs.

  • They don’t all build webs. Jumping spiders, for example, hunt visually and track their prey using a mechanism in the back part of the retina – their eyes do not move.

  • They have advanced care for their young. Female Nursery Web Spiders, commonly called dock spiders, carry the egg sack, which contains up to 1,000 little eggs, in their jaws. Closer to hatching time, they build a special web and put the sack inside, and then guard the babies until they are ready to go out on their own.

  • Wolf spiders spin a hammock of silk around their eggs and roll it into a ball, which they then carry on their backs. Once hatched, the babies climb on the back of the mother and she carries them around until they are big enough to leave on their own.

Nursery Web Spider with egg sac.jpg