Harbingers of change: Temperate owl ranges expand to Alaska, Kenai Peninsula

Refuge Notebook

Posted: Friday, February 29, 2008

Late winter is the time of the year when residents of the Kenai Peninsula often become aware of our local owls.

As breeding cycles begin anew, owls start actively vocalizing to attract mates and establish and defend breeding territories.

While most species of owls can be characterized as nocturnal and a few as diurnal, almost all of our owl species are "crepuscular" to some degree, meaning that they are more active during the morning and evening twilight periods.

If you are hoping to see an owl, these are the prime times since the probability of detection is significantly increased. Of course if you don't need to see an owl, you can merely wait for the dark of night to descend and patiently listen for their nuptial songs.

There are eight species of owls that frequent the Kenai Peninsula either as winter visitors, summer breeders, or year-round residents. They are great gray owl, great horned owl, snowy owl, short-eared owl, northern hawk owl, boreal owl, northern saw-whet owl, and western screech-owl. The last two species are relatively new additions to the avifauna of the Kenai Peninsula.

The northern saw-whet owl was considered a very rare resident of Southeast Alaska prior to the 1950s. During the 1950s and 60s they expanded their range northwest into Southcoastal Alaska and beyond to the Alaska Peninsula.

They were extremely rare on the Kenai Peninsula during the 1960s but were quite common by the 1990s. They are currently our most common small owl, apparently usurping that distinction from the boreal owl.

The northern saw-whet owl is approximately eight inches in length, lacks ear tufts and is most frequently detected by its nuptial song which consists of monotonous single whistled toots, roughly two seconds apart.

The western screech-owl was also considered a very rare resident of Southeast Alaska before the 1950s; prior to 1980 there was no evidence that they were present northwest of Yakutat.

During the 1980s they colonized Southcoastal Alaska and were first detected on the Kenai Peninsula during the early 1990s. The Kenai Peninsula is currently the northwestern outpost of this rather uncommon species.

The western screech-owl's nuptial song consists of a two-part series of quavering or tremulous whistles. It is a small owl averaging eight and a half inches in length with very small ear tufts.

The northern pygmy-owl was formerly found only in southernmost Alaska during the early 1900s where it was extremely rare. Though currently an uncommon owl, it is consistently found as far north as Yakutat and has been detected as far west as Valdez.

Though it is less than seven inches in length, the northern pygmy-owl is an aggressive diurnal bird-predator that will take prey larger then itself. Its nuptial song consists of a series of widely-spaced hollow, whistled toots similar but significantly slower than that of the northern saw-whet owl.

The barred owl was formerly limited to the eastern forests of North America, but during the 20th century its range rapidly expanded north and westward across the continent. It was first recorded in Alaska in 1977. During the ensuing years it has proliferated to the point that it is no longer a rare owl, now commonly found north to Skagway.

The barred owl averages 21 inches in length, lacks ear-tufts and prefers river bottoms and swamps. Its loud, distinctive "hoots" are characterized by the mnemonic phrase, who-cooks-for-you, who-cooks-for-you-all.

The long-eared owl formerly did not breed north of Prince George in central British Columbia. During the past decade they significantly expanded their breeding range northwest to the Kluane Lake area of the Yukon. This owl has recently been observed in eastern Interior Alaska and one can't help but wonder if it will soon breed there as well.

As its name implies, the long-eared owl has long conspicuous ear-tufts, the body is approximately 15 inches in length, and it's a nuptial song consisting of one or more drawn out hooo's.

The short-eared owl is a common breeder on the Kenai Peninsula that migrates out of our area in August and September and returns in late April and early May. Recently several individuals have been discovered over-wintering in Seward, Homer, and the Anchorage area.

This is remarkable, because short-eared owls were not previously known to over-winter west of the Copper River Delta. We may be witnessing a significant change in their status on the Kenai Peninsula from summer breeder to year-round resident.

The short-eared owl's nuptial vocals, a series of raspy barks, can be heard principally in spring and rarely in winter. It appears to be without ear tufts but upon closer scrutiny, inconspicuous ear tufts can be discerned on this 15-inch-long owl.

Over the last 50 years we have witnessed dynamic change in the ranges of these six species of owls. They are conspicuous harbingers of change. They also remind us that not merely is our regional and local avifauna in flux, but rather all biotia, flora and fauna, and abiota, geology and meteorology. Whether we recognize it or not, the face of Alaska and the Kenai Peninsula is constantly changing.

Toby Burke is a refuge biological technician who is intrigued by the status and distribution of Alaska and Kenai Peninsula birds and enjoys birding with his wife and family.

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Previous Refuge Notebook articles can be viewed on our Web site, http://kenai.fws.gov/. You can check on new bird arrivals or report your bird sighting on the Kenai National Wildlife Refuge Birding Hotline at 907-262-2300.

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