Northern Saw-Whet Owl

## Description

The northern saw-whet owl (Aegolius acadicus ) is a small owl native to North America. Saw-whet owls are one of the smallest owl species in North America. They can be found in dense thickets, often at eye level, although they can also be found some 20 feet up. Saw-whets are often in danger of being preyed upon by larger owls and raptors. Northern saw-whet owls are also migratory birds without any strict pattern.

## Appearance

The Northern saw-whet owl is a small bird of prey with bright yellow eyes native to North America. It has a round, light, white face with brown and cream streaks. The underparts are pale with dark shaded areas and the upper parts are brown or reddish with white spots. Juveniles have dark brown head and wings, and a tawny rust-colored breast and belly. There is also a distinctly white, Y shaped coloration between their eyes.

## Distribution

Northern saw-whet owls are found in most of North America including southeastern and southcentral Alaska, southern Canada, most of the United States and the central mountains in Mexico. Some populations are permanent residents, while others may migrate south in winter or move down from higher elevations. These birds inhabit coniferous forests, sometimes mixed or deciduous woods, and also love riparian areas because of the abundance of prey there.

## Behavior

These birds are strictly nocturnal and solitary. They live in tree cavities and old nests made by other small raptors. During the day Northern saw-whet owls usually roost in dense foliage, close to the end of a branch. At night, they hunt waiting on a high perch and when the pray is spotted they swoop down to capture it with talons. Northern saw-whet owls are generally silent and vocalize mostly during the breeding season making a repeated tooting whistle sound; they usually make these sounds to find a mate. Some say they sound like a saw being sharpened on a whetstone. Other vocalizations include the Advertasing call, the Rapid call, Whine, Ksew call, Tssst call, Squeaks, Twittering call, Guttural chuck, and begging calls of nestlings. Non-vocal sounds such as bill snapping are used as a warning call by adults, juveniles and nestlings usually when approached up close or when in the hand.

## Diet

Northern saw-whet owls are carnivores. They mainly eat small mammals and also supplement the diet with small birds, with passerines such as swallows, sparrows, kinglets, and chickadees. On the Pacific coast, these owls may also eat crustaceans, frogs, and aquatic insects.

## Reproduction

Northern saw-whet owls are serially monogamous and form pairs that last only during one breeding season. However, at times when prey is abundant males may mate with more than one female (polygynous behavior). Females sometimes may also leave their partners with the nestlings and mate with another male and raise a second brood (polyandrous behavior). Northern saw-whet owls breed between March and July. During this time males will often sing from a nest sight and cache food in nests in order to attract a female. Pairs nest in natural tree cavities, in old woodpecker holes, and also in nest boxes. Females lay about 4-6 white-colored eggs and incubate them about 26-28 days alone. During this period the male does the hunting. Owlets hatch altricial; they are blind a covered with white dawn. The parents feed and protect their young about 4 to 5 weeks of age until they fledge and are able to fly. Owlets become independent when they are 6-8 weeks old and start to breed at one year of age.

## Population

### Population threats

Northern saw-whet owls are quite common but declines occur due to habitat loss and competition with Boreal owls, starlings, and squirrels for nest cavities. These small birds are also in danger of being preyed upon by larger owls and raptors.

### Population number

According to the IUCN Red List, the total population size of the Northern saw-whet owl is around 2,000,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.

## Fun Facts for Kids

Saw-whet owls are one of the smallest owl species in North America.

The advertising call of Northern saw-whet owls sounds as 'too-too-too' and can be heard up to 300 m away through the forest.

Like many owls, these birds have excellent hearing and exceptional vision in low light. Their hearing is very sophisticated, due to vertically asymmetrical ears and different shape of the ear openings. Because the sound reaches the ears at a different time and is of different intensity, Northern saw-whet owls can very precisely localize their prey. Such accurate sound localization allows them to hunt in complete darkness by hearing alone.

When sensing danger, Northern saw-whet owls elongate their body to seem like a tree branch and often bring one wing around to the front of their body.

During cold winter months when the stored food freezes, Northern saw-whet owls may thaw it by "incubating".

## References

https://animalia.bio/northern-saw-whet-owl