Sunday, November 8, 2009

Wrong Way Corrigan

Our own Wrong Way Corrigan after her recapture (©Tom LeBlanc)

In 1938, aviator Douglas Corrigan made a transcontinental flight from California to Brooklyn. Flush with his success, he wanted to try another nonstop flight immediately, this time across the Atlantic from New York to Europe. He'd been trying to get permission for the flight for two years, but his rickety plane, which was basically held together with spit and baling twine, was not considered safe, and his flight plan was again denied.

Corrigan took off, supposedly to return home to California. Instead, he landed 28 hours later in Belfast, Ireland, and until his dying day he swore that he'd simply gotten lost. Manhattan threw him a tickertape parade, the New York Post ran a backwards banner headline that read HAIL WRONG WAY CORRIGAN, and a legend (and an expression) was born.

It looks like we have our own Wrong Way Corrigan. On Oct. 26, my crew and I banded 24 saw-whets at our Hidden Valley site in Schuylkill County, just north of the town of Friedensburg. The last owl of the night was an after-second-year female (meaning she was at least three years old, possibly older).

Imagine my surprise when I learned that this same owl was recaptured Friday night - not south of us, as you'd expect, but in Allegany State Park near Salamanca, New York, at a site run by bander Tom LeBlanc.

That's almost 170 miles to the northwest - the wrong way for any bird that's supposed to be migrating south for the winter.

The odd thing is, this isn't all that odd. Coincidentally, the day before this recapture, a number of saw-whet banders had been discussing birds moving in unexpected directions - speculating whether this was a result of immature birds undertaking a form of dispersal flight, or a manifestation of the nomadism many of us suspect is a constant theme in saw-whet life.

The subject arose when banders in Massachusetts twice recaptured (at two different sites) an owl banded in a previous fall in Kentucky. Some of our birds banded in Pennsylvania have subsequently been caught in Illinois, Michigan and Ohio, and we've caught owls banded in Michigan, Wisconsin and western Ontario. But in most of these cases, a year or more elapsed between banding and recapture.

Last year, however, another of our owls (also an adult) made a long flight to the northeast, showing up 118 miles to the northwest a week after we banded her, in nets run by our colleague David Hauber near Hebron, PA.

So what's going on? I tend to think this has less to do with "lost" owls and more to do with an evolutionary approach that uses nomadic behavior to find areas of abundant food, both during breeding and nonbreeding seasons. After all, historians like to point out that whatever his claims to the contrary, Corrigan certainly knew exactly where he was flying.

There is circumstantial evidence to suggest that saw-whets are highly nomadic during the nesting season - that unlike most birds, which return faithfully to the same nesting territory every year, saw-whets may slosh around the boreal forests of Canada and the northern United States - maybe in Quebec one year, and the next in central Ontario, where the mast crop (and thus the rodent population) is higher. Then in the fall, instead of coming south through New York and Pennsylvania, the owl crosses through the Great Lakes region into Michigan and Illinois.

They may also be nomadic in the nonbreeding season, too, shifting widely across the landscape. While rare among raptors, such constant wandering is common among many boreal birds, like crossbills and pine siskins.

This is just speculation, but our geolocator study may shed some light on these questions. Because the data loggers will collect information from which we can plot the rough daily position of the owl for up to two years, we may finally get some hard evidence to explain whether they are as nomadic and unpredictable as these rare banding encounters suggest.

Unfortunately, because I was shorthanded the night we caught this owl, I didn't fit her or most of the other saw-whets that night with geolocators. But I suspect the owls we have fitted with the devices will provide some real surprises when we start recovering some of the geolocators next year.

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