The Boreal Owl

The Boreal Owl ranks as one of the most wanted bird species on most birders North American list. The reason it's so hard to find can be summed up with one word "location". In North America its breeding range extends from the Maritime Provinces West to Alaska. It also breeds locally in the mountainous regions of Idaho, Montana, Wyoming, Colorado, and New Mexico. When found in the western U.S. it occurs above 5,000 ft. Its range appears to have expanded South over the past few years or else our understanding of its current range has increased.
It has also been recorded nesting in northern Minnesota and most recently in New Hampshire. The owls located in New Hampshire are consider to be the first for the Eastern United States. The birds were found in late July at a high elevation in the Crawford Notch area of the White Mountain National Forest. Another Boreal Owl was heard and then banded on Vermont's Stratton Mountain in mid-June. This came after a very productive winter for northern owls in that region.

The best information available on this species comes from owl banding stations around the Great Lakes. The banding station at Whitefish Point in northern Michigan is the most notable. (Whitefish Point is also famous as the home of the shipwreck museum featuring the Edmund Fitzgerald). Spring owl banding operations have been in effect there since 1982. Since then hundred of Boreal Owls have been banded. One owl banded in April of 1997 was later recovered dead in December of 1997 over 1,000 miles away. Normally less than 1% of owls banded are ever recovered. Most recoveries come from road-killed birds or those found dead in barns or near bird feeders. This low recovery rate makes it difficult to fully understand the migration pattern of this elusive owl.

Boreal owls are not true migrants but irruptive in nature. Banding at Whitefish Point suggest a 4 to 5 year cycle of irruption. This is apparent when you look at the high banding Totals for Whitefish Point during 1984, 1988, 1992, 1996 and 2000. The Year 2004 has turned out to be the next irruption year with 300 Boreal Owl's banded in Minnesota on the north shore of Lake Superior. The reason for this irruptive nature has to do with the prey population in the North. When the food supply runs low the owls are forced to travel South in search of a better hunting areas. In years when prey population is good, few if any Boreal Owls reach Whitefish Point.

In the spring, the main thrust of owl migration through Whitefish Point comes the last two weeks of April and the first week of May. However, Boreal Owls have been banded from the end of March through the end of May. Some may linger into June but banding at the point ends May 31st.

If you plan to go to Whitefish Point during the migration in search of this owl, check the Michigan bird hot lines to see if any owls have been banded. A good place to start your search is in the Jack Pines near the point. Boreal Owls roost in the day in thick foliage in trees near the point. They prefer the safety of evergreens. Four Boreal Owls were found roosting in the Jack Pines here on Members Weekend April 26, 1997.

Bird Hot line numbers for Michigan include:

• Detroit Audubon Society at 1-248-477-1360
• Sault Ste Marie Audubon Society at 1-705-256-2790

Boreal Owls start to migrate South through Whitefish Point at the end of September. The peak migration time is during mid October. Owls banded at Braddock Bay show that some times Boreal Owls travel South to New York during the winter. They have also been known to travel to Boston in 1996 and again in 2000. Boreal Owls have also paid visits to Ohio in 1997 and most recently to New York's Central Park in December 2004. However, these are rare occurrences and far beyond their normal range. These owls of the North seldom travel South of the extreme northern portions of the U.S.

When located the Boreal Owl can be quite trusting allowing for a close up view. This can be a great photo opportunity. It's this attribute that caused the Inuit to name this bird Tuckwelinguk, meaning the "blind one". Inuit children also make pets of Boreal Owls. However, for the safety of the owl please do not take advantage of this trusting nature. It's best not to disturb an owl's safe hideout. Hopefully the owl will remain in the same spot for several days.

Whitefish Point offers the opportunity to sponsor a Boreal Owl. They will send you a 5x7 photo and a certificate of sponsorship. If the owl is ever recaptured or found they will send you this information. They also have other owl species that you can sponsor. To find out more about their program contact WPBO in Michigan.

Most owls have some folklore associated with them. The Cree people believed Boreal Owl whistles were summons from the spirits. If a person answered with a similar whistle and did not hear a response, then he would soon die.

Boreal Owl fact sheet:

1. Length: 8.3 to 12.2 inches (21 to 30.9 centimeters).
2. Wingspread: 19.7 to 25.8 inches (50 to 65.5 centimeters).
3. Flight style: Direct with rapid wing beats.
4. Voice: A slow, high-pitched, to-to-to, like the sound of dropping water or a series of musical, cooing notes.
5. Nesting: Natural cavities in trees, abandon woodpecker holes and rarely nest boxes. Generally 10 to 25 feet off the ground.
6. Eggs: 4 to 6 white. Incubation 25 to 27 days. May produce two broods in a year.
7. Etymology: The scientific name Aegolius funereus translates into "funereal bird of ill omen".
8. Fledging: 30 days.
9. Similar Species: The Boreal Owl can be confused with the Northern Saw-whet Owl but is about 25% larger, is darker overall, has fine spots rather than fine streaks on its head, and has a yellowish rather than grayish bill.
10. Food: Small rodents like mice and voles make up 90 - 98% of its diet. Small birds and some insects account for the remainder. It normally hunts at night but will also hunt in the day when feeding young.
11. Pellets: Small gray pellets are ejected about 1.2 times per day.
12. Habitat: Conifer, or mixed conifer-deciduous forest. Preference is for old growth habitat in the north. Southern populations prefer high subalpine forest near open meadows.
13. Roosting: When roosting it needs dense conifers of spruce or balsam fir where it roosts 5 to 20 feet high. When roosting it perches on a branch next to the trunk.
14. Hunting: The Boreal Owl is mainly a nocturnally but may hunt during cloudy daylight hours. It is a "sit and wait" predator that locates prey mainly by hearing.
15. Subspecies: There are 7 recognized subspecies in the world, only 2 of which have been found in North America.

By Marshall Helmberger

Since 1987, biologist Bill Lane has spent hundreds of chilly late winter evenings traveling the back roads of Lake and Cook counties, listening for boreal owls. Ten years ago, he might hear several singing male owls on a typical night. During the course of a single breeding season, he has recorded as many as 88 of these small and secretive northern owls in the roughly 800 square mile territory that he has surveyed each spring.

But in recent years, the song of the boreal owl has all but disappeared from Lane's stomping grounds. In the spring of 2006, he heard just one singing male. The year before, he didn't hear any.

"After 2001, it just flatlined," said Lane, who lives in Tofte.

That data, from the only long-term boreal owl population survey in the state, has prompted the Department of Natural Resources to propose the owl as a threatened species in Minnesota, a move that would give the species legal protections it currently doesn't enjoy.

That proposal, which came as part of the agency's once-a-decade updating of its list of treatened, endangered, and special concern species, is good news to Lane. "It's a huge step for the agency," he said, noting that the DNR rejected his suggestion to list the species as one of special concern back in 1996. But this time around, DNR biologist Rich Baker said Lane's data, especially his documentation of the dramatic population falloff, helped convince the agency that the owl was in trouble in Minnesota and needed protection.

Baker acknowledges the decision is likely to prove a controversial one. Indeed, of the more than 100 proposed changes in the DNR's threatened and endangered list, the boreal owl is the one that has most captured the attention of the state's timber industry. "It's the one that concerns us the most," said Tim O'Hara, a spokesperson for the Minnesota Forest Industries and Timber Producers. "In past experience, as with the spotted owl out West, this could impact harvest levels, so, of course, that's a concern," he said.

Unlike the spotted owl, however, researchers like Lane and others say there's no evidence that the boreal owl needs large tracts of undisturbed forest. But researchers like Lane, and Steve Wilson, of Tower, who has also tracked boreal owl populations for years, have documented clear habitat preferences. Perhaps the clearest need, says Lane, is big, old aspen trees, which make good nesting locations for the cavity-nesting owl. Lane, who has recorded more than 80 boreal owl nest sites during his 20 years of work, says 92 percent of them were in old aspen, with an average age of 85 years.

Wilson's research has found less of an affinity for aspen among boreal owls in St. Louis and northern Lake counties, where most of his work has been based, but he said the owls are clearly dependent on large, old trees or snags for nesting cavities. They also depend on the presence of pileated woodpeckers, which typically excavate the cavities subsequently used by owls.

Lane said the number of those old trees has been on the decline in recent years, due to a combination of timber harvesting as well as the impact from the 1999 blowdown, that affected much of his survey area. Indeed, Lane thinks the blowdown may have played a major role in the falloff of boreal owl populations in recent years, because the storm blew down so many of the old cavity trees. Wilson isn't so sure, noting that the population of saw-whet owls, another small, cavity-nesting owl, rebounded quickly after an initial dip in the wake of the blowdown.

Lane acknowledges that saw-whets appear to be doing well, which means some cavities are still available in his survey territory. But he believes saw-whets are more adaptable to the changed landscape in the region and may now be outcompeting boreal owls for a limited supply of available nesting sites.

Given his concern about a lack of nesting cavities, Lane has begun putting up nest boxes along parts of his survey route. Of the 100 boxes he had installed as of last spring, saw-whet owls occupied more than 20. Boreal owls took up residence in two. "To tell the truth, I was completely shocked by the amount of use," he said, suggesting that it could well point to a shortage of nest cavities.

It turns out, big trees may not be the only habitat requirement of the boreal owl. Both Lane and Wilson have found that the owl also has a clear preference for mature stands of lowland conifers. In fact, they both say the owls almost always nest within a short distance of such a stand. "I've never found a nest that wasn't in close proximity to lowland conifer habitat," said Lane.

Neither researcher could say for sure why the owl prefers lowland conifers, although they agree such stands may offer the owl protection from larger predators, like great horned owls, as well as some thermal protection on cold nights and possibly better hunting.

Timber industry officials aren't as convinced by the research, although O'Hara acknowledged his group has yet to review Lane's date. He said MFI would be consulting with its own biologist to see if the proposed listing of the owl is warranted. "We'll be reviewing it and sending our comments," he added.

O'Hara suggested the industry may also raise the issue of whether state regulators should concern themselves with a species like the boreal owl, which is still relatively common north of the border. "If it's doing fine in Canada," he said, "you have to ask what is the state's role in protecting it?"

Lane said it's not just a question of protecting an owl, but of maintaining a habitat type that serves a wide range of different species. "I prefer a holistic approach for all species," he said. According to Lane, it's just a matter of protecting a piece of Minnesota's northwoods legacy. "I fully anticipate there will be a huge stink over this listing. But in the end, it's about doing what's right, rather than what's in someone's self interest. I want people to be able to hear this owl singing long after I'm gone."