Northern Saw-whet Owl (Aegolius acadicus)
By Cookie Ferguson
Who “Toots” in the Woods?
Walking in the woods on a brisk evening in October or November a birder would be listening for many sounds….maybe you’d hear a deep, low…”Who-ooo-oo”. Right away you think Great Horned Owl. Or you might hear a more mellow…”Who cooks for you?” and your mind goes to the more common and vocal Barred Owl. You go a little deeper in the woods and you hear a rather continuous medium pitched “Toot, toot, toot, toot…” What bird comes to mind? You are lucky enough to be hearing the sharp tones of the small, migrating Saw-whet owl.
The Saw-whet owl is one of the cutest mysteries of the avian world. It is about 8 inches tall and weighs less than your cell phone. Yet it migrates in the spring and fall between Canada and northern Georgia it is thought. The first year males and females lead the migration and make up the majority of the owls that migrate. The older males seem to stay in their northern breeding grounds “toughing it out” through the winter to protect their territory.
Because of the owl’s secrecy, much research is being done to study these wonderful owls. There are several stations in Indiana where these owls are captured, measured, and released. They are at Mary Gray Bird Sanctuary, Yellowwood Forest, Indiana Dunes, Purdue University, and Ball State. This process begins in mid-October and is usually finished mid-November. The owls are lured into nets using callers. The nets are about 30 feet long and 15 feet tall. Each net has four tiers or “pockets” into which the owl falls. Nets are checked every hour after the nets are unfurled at sunset. Researches continue checking the nets well into the night or until there are no owls found for two checks. At the Dunes five such stations are run. A captured owl is put in a cloth bag to be transported to the banding area. (They do not struggle or get stressed as they have no contact with humans previously.)
Once at the banding area a band with a nine digit number is put on and the owl is measured–beak length, folded wing from shoulder to tip, tail length, and weight. You can imagine they don’t sit on tiny scales. They are measured in grams by gently sliding the owl into a plastic sleeve and placing upside down on the scale. Owls weigh around 100 grams. Males weigh less-females more. Once that is done a combination of that weight and feather color (new feathers shine bright pink under blue light) are used to determine age.
All of this data is recorded for each owl as well as the date, temperature, wind, moon phase, time of capture, and place of capture. At the end of the season the information is uploaded into a national data base. From there if an owl is recaptured, the data will tell when and where the owl was banded. Researchers are tracking population numbers, how long they might live and where they actually migrate as well as other vital data. One of the owls banded in the Dunes was recaptured at Arcadia National Park in Maine and another in Saskachewan. Who would guess? One of nature’s little secrets slowly revealed.