Screech Owl

This morning I listened to great horned owls courting in the pre-dawn hours and the night before last I was awakened by a screech owl’s high pitched whinny. It’s also January, the month many owls are creating territorial space for breeding, so it’s no wonder that owls are on my mind.
 
The ‘who ho ho hoo hoo hoo’ courting call of the male – a sort of mild monochromatic whoohing - is a very pleasing sound while the haunting whinny of the female is impossible to mistake. The latter, the female’s call, awakened me in the middle of the night two nights ago, but I never heard a male respond. I give thanks every single day for living so close to water because owls are drawn to wetlands for hunting and I have a penchant for all owls.
 
My friend Andrew who lives in El Rito had a remarkable experience with a couple of western screech owls. In his own words, returning to his unfinished house after having been away all winter he writes,
 
 “The evening I got in, I set the mattress down on the floor of the kitchen and went to sleep.  I woke up and looked up at the beams and there they were!!  Two gorgeous creatures staring down at me.” 
 
The two little screech owls were perched on the rafters above him. Oh, I would have given anything to see what he saw! Although they left after his return, he can still hear them calling.
 
Eastern and Western screech owls are different but very similar species that overlap in the Rio Grande valley. They both have white undersides streaked with black (a cinnamon colored variation exists in the eastern species). Both have identical   ear tufts and black circles around their yellow eyes. Sometimes the tufts are raised and at other times they are barely visible. The females are larger than the males. Eastern and western screech owls are usually told apart by their bill color that is greenish gray for the eastern type and gray to black for the western owls.

The two owls also have slightly different calls with the western species sounding a bit more like a wail (though personally I cannot make a distinction between the two). To stay in contact, screech-owls use a short "double trill" call; when agitated, they make a barking sound. Another interesting vocalization occurs when Screech-Owls snap their bills when approached closely by a potential predator, or someone like me who is on the watch for owls all the time. Nestlings begin making this noise when they are about 8 days old. It is most definitely a defensive call.
 
Screech-Owls live mainly in forested habitats, especially in bands of deciduous trees along wetlands and canyons. Common trees include cottonwood, aspen, and other poplars, alder, water birch, oak, and maple. It is also possible to find Screech owls in suburbs, parks coastal areas, and in mountains up to about 6,000 feet in elevation (Andrew lives at 7000 feet).

Screech-Owls are carnivores. They eat mostly small mammals, though they also feast on birds, fish, amphibians, and invertebrates including scorpions. Their diet can vary tremendously from place to place and from season to season. Mammal prey includes pocket mice, deer-mice, grasshopper mice, shrews, wood -rats, kangaroo rats, as well as bats and rabbits. Invertebrates include insects, crayfish, worms, slugs, snails, and whip scorpions.

Like most owls Screech owls are sit-and-wait predators, perching inconspicuously on tree branches peering around for a meal. They also sometimes sit above creeks and rivers watching for crayfish to emerge from the shallows. They snatch invertebrates from foliage and catch flying insects in midair. They prey on bats leaving a roost.

Like many small owls (8 inches in length), Screech owls nest in tree cavities excavated by woodpeckers. They may also use naturally occurring cavities, such as those formed where branches have broken off a trunk. Occasionally, they nest in holes or crevices in cliffs and banks. Wherever the location, the male owl finds a suitable home, then calls or leads the female to it, sometimes by carrying an enticing prey item. A pair may use the same cavity for several years in a row.

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Screech owls don’t build nests, and apparently lay eggs on whatever material happens to be in the cavity. Nest holes are about 1 foot in diameter and 1 to 1.5 feet deep. Entrances are just big enough to admit an owl's body; presumably this helps prevent larger predators from getting in. Sometimes they take over the nests of other species. The clutch size varies from 2 – 7 pure white eggs that fledge in about a month.

These owls are "socially monogamous," meaning that pairs raise young together, although both sexes may also mate outside the pair. The male and female often preen each other. During courtship and mating, they sing duets, and the male presents food to the female.

In breeding season, the male roosts near the nest cavity. During the last weeks of the nestling period, the female also leaves the nest, often roosting close enough to the male that their bodies touch. Both adults guard the entrance from crows, jays, ravens, raptors and other predators. The male provides almost all the food for the female and young during nesting, while the female incubates eggs and broods the baby owls. The mother stays with her young constantly for the first 3 weeks before taking increasingly long breaks to help the male hunt. Owlets leave the nest before they can fly well. They remain with their parents for about 5 weeks after leaving the nest.

Screech-Owls are strictly nocturnal. The owls leave their roosts at dusk to forage, returning within a half-hour of sunrise. It is possible to glimpse them perching at the entrances of their roost cavities on sunny winter days although I have yet to see one – one reason I have made it a priority to learn different owl calls.

Screech-Owl population trends are difficult to study because of the birds' nocturnal habits. The North American Breeding Bird Survey reports that its sample sizes are not large enough to adequately estimate population changes in this species, but populations have declined significantly between 1966 and 2018. In the west they are on the State Bird Watch List that targets bird species that are at risk for becoming endangered without conservation action. High-density development clear-cut forestry and wild fires have taken a heavy toll on all screech-owl habitat. These owls are also dependent on standing dead trees containing cavities for their nest sites.

Although I no longer do the winter owl count for Audubon, I remember the thrill of hearing these little owls call during the early pre-dawn hours from 2 – 5 AM. I am hoping that the female I heard has a mate and will find a nesting place somewhere close by so I can hear these little owls again. 
 
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