Saturday, February 21, 2009

Take-out Food

Lexi with a snack. (©Aura Stauffer)

Same church, different pew, as they say...Aura checked on Lexi Friday, who was in a larger white pine within the same grove as the past three weeks, although perched only about four feet off the ground.

She was also holding a bag lunch, but for once it wasn't a Peromyscus (white-footed or deer mouse) but what appeared to be a meadow vole. Aura and I had just been talking on Thursday about how Lexi seemed to be targeting Peromyscus, even down in the valley where we'd expect voles to be more common. Maybe she overheard us, or maybe Thursdays are Vole Night at the saw-whet bistro.

Tuesday, February 17, 2009

A rough neighborhood

For the past two weeks, Lexi has remained in her new digs, in a grove of young white pines on private land along Yellow Breeches Creek, about 3.5 miles from where she spent most of the winter in King's Gap State Park.

Aura Stauffer has been checking her every few days, and although Lexi seems to be switching roost trees every day or so, she is apparently living high on the hog - or the mouse, at least. Aura's collected a lot of pellets, and more often than not, Lexi's been sitting on a mouse that she saved from the previous night's hunting.

But she's obviously not the only owl hunting these woods. The first day we located her there, Feb. 4, we flushed a great horned owl from the pines, and Aura's found fresh great horned pellets, as well as piles of pigeon feathers that may have been left by GHOWs or other large raptors.

Saw-whets are the bottom of the raptor totem pole, and all other Pennsylvania owls, including screech-owls (which weigh twice as much as a saw-whet) may kill and eat them if given the chance. We can only assume that Lexi's careful, and we hope she remains so.

I was a little surprised, given the mild weather last week, that she didn't pull out and begin moving north. The peak spring migration in Pennsylvania seems to be around the beginning of March, although that probably varies from year to year depending on weather and snow cover. We're nearing the latest date that we've ever had a radio-tagged saw-whet remain, so Lexi may be about to set a new record for us.

Sunday, February 8, 2009

Down in the Valley...

It's been a couple of weeks since we wrapped up the intensive tracking portion of our fall/winter research season (and since I updated this blog), but we still have one radio-tagged owl - Lexi - remaining on the study area. Although we're no longer conducting night-tracking, Aura Stauffer and I have been doing roost checks on her every few days.

Initially, Lexi was staying up in her usual haunts, high in King's Gap Hollow below Buck Ridge, but around Jan. 25 she shifted to the west, sometimes on private land near the park (judging from her signal location), sometimes on park property off the Boundary Trail. Then, after briefly returning to the Buck Ridge area, she made a dramatic move.

On Groundhog Day, Aura located Lexi's signal down in the valley more than three and a half miles from where she'd been roosting, and two days later, Aura and I located her sitting in a plantation of young white pines on private land along Yellow Breeches Creek. This is only a little more than a mile from a riparian woodlot where we tracked her hunting one night last month; maybe she got tired of making the commute. The farmer on whose land she's staying said he sees a lot of raptors there, and we flushed a red-tailed hawk and great horned owl as we hiked in that morning.

I just got back from checking on Lexi again today, and she's still tucked into the same grove of 30-foot-tall pines. I was accompanied this morning by Ohio saw-whet bander Kelly Williams-Sieg and her friend Lisa Ratcliff, who drove up to get some experience radio-tracking. I visited Kelly's terrific banding station in Chillicothe, OH, last winter, and was delighted to repay the hospitality. The fact it finally felt a bit like spring today -- mild temps, singing song sparrows and Carolina wrens, and flocks of ring-billed gulls migrating overhead -- only made the day more enjoyable.

The weather is supposed to stay mild through the first half of the week, and it will be interesting to see what Lexi does. I would expect the first push of northbound saw-whet migration to begin about now, and her move to the valley site might be a sign of pre-migratory restlessness. We'll be keeping an eye on her, and I wouldn't be surprised if she starts moving north in the next week or so.

We've only been able to follow two other saw-whets this late into the winter - a bird we nicknamed "The Grinch" in 2007-08, which we finally lost track of Feb. 2, and an unnamed bird in 2003 whose signal disappeared about Feb. 16 - whether because it migrated, or because the battery died, I can't say. If Lexi hangs in there, she may set a new record for us - but even if she leaves tomorrow, we've amassed a ton of roost and nighttime activity data on her.

Finally, it was farewell and good luck to our fall research technician Anna Fasoli and research intern Drew Weber, who both did such a fantastic job for us this season. Anna's going to be doing some volunteer work with her old love, whooping cranes, in Florida, then helping on some conservation work in Hawaii before starting a new position in Nebraska this spring tracking endangered plovers and terns. Drew, meantime, will be pursuing graduate school in ecology and conservation. We were incredibly luck to have both of them participating in this project, and they'll be missed.