College of Veterinary Medicine |
Sawyer

Healthy Animals, Healthy People, Healthy Planet

Sawyer is a Northern Saw-whet Owl

Sawyer is a Northern Saw-whet Owl (Aegolius acadicus) found in the bushes of someones backyard in 2013 so they brought her into the vet hospital.  She sustained an injury that does not allow her to extend her left wing so she joined the club in August 2014. DNA testing would have to be done to know the sex of Sawyer since males and females do not differ in coloration; however females are on average 20% larger than males.  Because of her larger size, Sawyer is suspected to be female.  Sawyer came to us as an adult and because of that, we are unsure of her age.

Saw-whet Owls are the 5th smallest owls in North America.  The 4 species that are smaller are the Northern Pygmy Owl (Glauciduim gnoma), Ferruginous Pygmy Owl (Glaucidium brasilianum), Flammulated Owl (Otus flammeolus) and Elf Owl (Micrathene whitneyi).  Because they are so small in size and highly nocturnal, the sawwhet owl is very hard to spot.  The name of the Northern Saw-whet Owl is derived from the sound of their voice which resembles "whetting" which is the sharpening of a saw. Usually this shrill call will be given many times in succession. Additional vocalizations include whines, gutteral sounds, tsst call, squeaks and high-pitched barks.  Saw-whet Owls can be identified by their brown plumage, light colored facial disks, and lack of ear tufts which make them very round in appearance.  They also have feathering down to their toes which helps keep them warm in cooler climates.  Juvenile Saw-whet Owls have dark feathering on their wings and head and orange-colored chests, with the prominent white “v” between their eyes.  They retain this juvenile coloring until they are 1 year old.

The white “v” can be seen on adult Saw-Whet Owls, but is accompanied by a predominantly white facial disk.  These little owls are prey for larger owls and hawks and it is thought that the faint white “v” on the back of their head may help to fool their enemies.  Predators avoid having their prey face them, and by having a “v” in front and behind them, a Saw-whet Owl may look like it has eyes on the back and front of its head!  The idea is similar to butterflies that have patterns on their wings which look like eyes.

Saw-whet Owls live in  dense coniferous forests throughout Northern North America,and during the winter season Saw-whets can be seen in dense forests across central and south US as well. Many will migrate while others will stay in the same area year round. Migration occurs at night only and they have been known to cross very large bodies of water, over 70 miles. During the day-time, Saw-whets roost in very dense vegetation around 11 feet above ground often hidden by the foliage near the outer edge of the branches of evergreen trees.  Nests are previously excavated holes usually made by woodpeckers that can be anywhere from 8-44ft off the ground. Mating season starts as early as late January and continues till May. Saw-whets are typically monogamous for the season, finding new mates every year, but if there is a good prey season females will take on more than one male.  When nestlings are around 18 days old, females will leave the nest and males will continue to feed the young. Saw-whets usually hunt small rodents from a low perch along the forest edge, but can also hunt juveniles of larger mammals such as squirrels or chipmunks. They will also eat insects and during migration Saw-whets will supplement their diet with smaller bird species.  Saw-whet Owls hunt primarily by sound.

Washington State University