Thursday, April 30, 2015

Guest student post: Short-eared Owl by Adrienne Feisel

Asio flammeus
The short-eared owl, Asio flammeus, or competitor of the barn owl has been endangered in Pennsylvania since 1985's Species of Special Concern in Pennsylvania. This endangered species is protected under the Game and Wildlife Code but also under the federal Migratory Bird Treaty Act of 1918.
Strangely enough, Asio flammeus is active during dusk, dawn and even during the day, so they are a more commonly spotted species of owl. They are medium sized (34-43 cm) with a wingspan that can range from 85-103 cm. The short-eared owl has long and rounded wings which make their wing beat slow resembling that of a moth. The underside of their wings is white while the tips of them are dark in color. They generally weigh around 206-475 grams with the females being a little larger than the males. Short-eared owls are pale in color with dark brown and white patches scattered on their bodies. They have short black bills, black talons, round-shaped big heads, big eyes, and small ear tufts. The name of "eared owl" comes from their appearance of having "ear" tufts, which are seen when the owl is defending itself. They are also characterized by the white ring of plumage that surrounds their eyes like a mask. Flammeus is Latin for "flaming, or the color of fire." This name suits them because they have large yellow-orange eyes, and each are each circled with black rings. Their voice can be described as that of a nasally dog bark, "wak-wak."

Asio flammeus pontoppidan belong to the family Strigidae and the Order Strigiformes. This family is the more diverse of the two. Their genus Asio only contains seven species. The short eared owl, Asio flammeus, has a decent number of subspecies, but only the species Asio flammeus flammeus is found in North America.
While their overall geographic range includes every continent except Australia and Antarctica and they have one of the biggest distributions in the world, they are found to declining throughout most of this range. On a smaller scale, in Pennsylvania, they are more commonly found during the winter in groups circling over fields in search for prey, meadow mice, but their overall abundance depends upon the amount of prey available to them. Their ideal habitats include areas of uncut grassy fields, meadows, strip mines, and even marshlands. They have been found in western PA nesting from Clarion County south to Allegheny County along with scattered areas within the middle of the state. But, the Breeding Bird Atlas from 2004-2008 only confirmed one breeding record, and they were only sighted within seven out of 4,937 atlas blocks in PA.

Even though these owls typically hunt meadow mice, they eat other animals like small birds, rabbits, bats, shrews and other small mammals. They most frequently use their asymmetrical ears and acoustical cues to hunt their prey.

Unlike you would expect, these owls nest on the ground in bowl-shaped depressions usually during May and June. Each clutch can range from four to seven eggs, which hatch around three weeks after the eggs are laid. The mother takes care of the young, and the father provides protection and food for the young. At the end of September/October, the breeding owls will migrate to their wintering grounds.

Unfortunately, their endangerment is due to an insufficient range of habitat available to these owls. Ideal habitats for the short-eared owl include areas of uncut grassy fields, meadows, strip mines, and even marshlands, but most of Pennsylvania's open land is farmland which is highly susceptible to disturbances. Due to these disturbances like intensive agricultural practices and development, the short-eared owl's habitat which is essential for nesting is being taken away. This decline is not only in Pennsylvania, but also all over the short-eared owl's entire geographic range.
Conservation efforts include constructing big, herbaceous reserves fitting for grassland nesters like strip-mines or large pastures. These areas should also be managed to assure that the Asio flammeus are able to have nesting seasons without any disturbances. There are several Important Bird Areas today which are sites that allow these owls as well as other wintering owls to nest disturbance free!
Anderson, J., Antifeau, T., Armleder, H., Bradry, M., Beauchesne, S., Bennett, R...., & Zwickel, F. (2004). Accounts and Measures for Managing Identified Wildlife. Identified Wildlife Management Strategy, (Version 2004), 121-128. Retrieved March 15, 2015.

Felbaum, & Mitchell. (2007, January 1). Short-Eared Owl (Asio flammeus). Retrieved March 15, 2015.

Haffner, K., & Gross, D. (2014, August 19). Short-Eared Owl: Asio fammeus. Retrieved March 15, 2015.

Liguori, S. (2010). New Jersey Endangered and Threatened Species Field Guide (B. Beans & L. Niles, Eds.). Retrieved March 15, 2015.

Short-Eared Owls. (2007). Retrieved March 15, 2015.

Short-Eared Owl: Asio flammeus. (2014). Retrieved March 15, 2015.

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