The Short-Eared Owl: A Diurnal Owl

This owl gets its name from two tiny feather tufts that may or may not be raised and evident. Most owls are nocturnal, so the Short-Eared is an exception to the rule. We see them in open country, usually on a fence post or on the ground. They seem to favor this type of country where they can more easily spot the voles and mice that make up a large part of their diet.

This owl of open grasslands is widely distributed over the world. Because of its wide distribution, it has many “nick-names”: Evening Owl, Marsh Owl, Bog Owl, Swamp Owl, Grass Owl, Meadow Owl, Flat-Faced Owl, and Mouse-Hawk. It spends more time on the wing than other owls, flying low over fields and marshes with wings in a V configuration (dihedral). It flaps its wings in a floppy, moth-like manner.

Because they live in the open, they are a quiet species. Visual displays are more useful than vocal ones in open country. The abundance of trees makes the use of sound more vital in woodlands. Short-Eared Owls rely on their coloration for camouflage, but will feign death to avoid detection. When they do sing, it is a pulsating “voo-hoo-hoo”.

Nests are constructed by the female (who is darker colored than the male) on the ground. It is a scrape lined with grass, herb stalks, and feathers plucked from her breast. She will lay anywhere from 4 to 14 eggs – depending upon yearly rodent cycles and their abundance. It is interesting how environmental conditions can subconsciously affect physiology.

Our most frequent sightings of this bird have been in the BLM lands on the way to Milner Dam, and also in the open country on the way to north Heglar Canyon.

(Dave Hanks)

Hiding in the barrow-pit along the Milner road

Burrowing Owls: Small, Open-Country Predators

Driving along sagebrush country roads in the morning hours, you might be lucky enough to spot a medium sized brown bundle of feathers with big imposing eyes. This is especially true if there happens to be fence posts lining the roadside. You would be witnessing a Burrowing Owl – an animal of the open sagebrush plateau and grasslands.

Burrowing Owls usually don’t burrow, although the male might modify a hole by scraping with his talons or on rare occasions dig one. They use abandoned ground squirrel, prairiedog, or other previously dug burrows. They will stand by the entrance but are quick to enter the security of the burrow when alarmed. If you wait, they will sneak back to the entrance to take a peek at their surroundings.

This owl stands 9 inches tall, has long legs, and big yellow eyes. It is a diurnal owl but will hunt when the moon is out. It kills by burying its talons in the victim’s back and then pecking vigorously at its neck. It will eat mice, voles, baby ground squirrels and rabbits, but rarely takes other birds. It does consume a large amount of insects such as grasshoppers and large beetles.

Both parents incubate the eggs (6 to 11) for a month and will bring food to the brood for 6 to 8 weeks. As the babies get larger, they will stand by the burrow’s mouth. A “cack-cack-cack-cack” alarm call by a parent on a nearby perch will send them scurrying back into the hole. The young are very vulnerable to predation and will hiss, like a snake, when threatened. The parents are also very intolerant of other species coming close to their burrow.

We have encountered this species sitting on fence posts when we drive the Yale road toward Heglar Canyon, or on the road to Milner by BLM land. This bird is migratory and we have observed them in the Imperial Valley of California in the winter. They seem to be abundant along the canals and alfalfa fields in the farming area south of the Salton Sea

On the alert on the edge of a hay field

Short-Eared Owl

ALONG THE MILNER ROAD
Short-Eared Owl (Idaho)
A diurnal owl (April)

Living Without Water: A Desert Adaptation

Water is essential to life. That being said, how do desert animals get by with practically none? One way is to conserve body moisture by being nocturnal. However, some rodents, such as the Kangaroo Rat and the Round-Tailed Ground Squirrel, have the ability to manufacture their own water from seeds.

The carbohydrates in seeds make this possible. The chemical make up of a carbohydrate is that every atom of carbon is attached to a molecule of water (C H2O). Simple sugar, the basic carbohydrate, is C6 H12 O6. Hence the term carbohydrate. All animal bodies break these molecules down during respiration in their cells and any excess H2O is excreted in the urine. If this water is retained, the need for additional is satisfied.

One would probably not expect to see much life in a desert because of the harsh conditions. It is always amazing to me to witness the variety of species we encounter there. Besides the birds, a favorite rodent of mine is found in arid areas.

The Antelope Ground Squirrel is an omnivore. It will consume insects, grasshoppers, and carrion, as well as vegetative matter. This squirrel can also go long periods without water. Unlike other ground squirrels, it does not hibernate. It digs an extensive burrow, two feet under ground, with two or three entrances.

This cute fellow is distinguished by a white stripe on each side of its spine. It prefers open areas and is diurnal (daytime active) which makes it more easily seen.

(An Antelope Ground Squirrel enjoying the cool of the morning)