Monday, January 19, 2009

Snowy night

This past weekend we had the worst cold to hit the mountains of central Pennsylvania since 1994 -- it was -8 at our house in Schuylkill County, and only marginally warmer at our South Mountain study site.

It appears that Maria may have left, at least the immediate King's Gap State Park area; ice and snow on the unmaintained state forest roads have made it hard to check whether she's simply moved to a new hollow. Lexi and Gemini remain, though, and Saturday afternoon - when the temp had clawed back above zero -- Anna Fasoli and King's Gap banding volunteers Jane and Maeve Charlesworth tracked down Lexi, high on Buck Ridge.

Last night Anna, new volunteer Lisa Rubin and I met at King's Gap to track Lexi, with snow squalls leaving a fresh coat. Fortunately, the temperature was nearly 30 degrees warmer than it had been the previous morning; in fact, the combination of dead calm and temps in the upper 20s made it one of the most comfortable tracking nights we've had in months - though I am a little nostalgic for swatting mosquitoes back in early October.

We sure got our exercise. What we've tended to see is that the owls leave their roost at dusk, move actively (sometimes covering long distances, as Lexi did last week), but after an hour or two they tend to settle in to one spot, sometimes not moving again for hours. We suspect they're flying from spot to spot until they locate an area with rodent activity, and once they make a kill, they'll plunk down to eat and digest. Because saw-whets usually eat one or two mice a night, we suspect they go through another period of active hunting sometime in the predawn hours, and we'll be looking at that next season, when we begin doing all-night monitoring (in the balmier nights of October and early November, not in subzero January weather).

Last night, though, Lexi didn't settle down. She stayed along the top of Buck Ridge, moving frequently enough that her signal kept fading in an out, and for most of the next six hours we chased her (slowly, carefully, quietly) around the mountain. We'd get into a good position, Anna and Lisa in one place and me several hundred meters away so we had converging angles with our receivers - and the owl would move. And again. And again.

At one point, I moved in several hundred meters with no headlamp, trying not to slip too much on the ice- and snow-covered rocks, when the owl apparently flew in and landed almost on top of me. She did the same thing and hour later, after we'd made an enormous loop and wound up halfway down the mountain near where we started.

It wasn't until 10:30 p.m. that Lexi's signal finally localized near the firebreak in King's Gap Hollow. Whether she 'd just felt the need to stretch, or was having trouble finding prey, she must have found something good. When we left her after 11 p.m. she hadn't budged in more than half an hour, and was presumably enjoying some warm mouse meat.

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