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.
Tuesday, February 17, 2009
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.
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.
Wednesday, January 21, 2009
Gemini and Maria: "flew the coop?"
Right: Carl searching for Gemini near Tom's Run (Photo: Carl Leinbach)Below: Lexi barely visible in a pitch pine
Yesterday, I went out tracking with volunteer Carl Leinbach to find Lexi's roost location. Carl and his wife, Pat, live nearby, and have been faithful volunteers for the entire season.
Mainly, they joined us for night-tracking, running around the woods and helping us chase down owls. It was great to have their company and help, and I will greatly miss working with them!
This was the second time Carl joined me on a roost check. A few months back, we tracked Quasi to a pitch pine, and documented it as her second use of the same tree. Lexi was again roosting towards the Buck Ridge, so we trekked up the steep slope that we have hiked more times than we can count in the last four months. We were having a few receiver problems, and ended up switching between 2 receivers to locate the owl (we think that the cold temperatures were interferring with the transmitter on the owl, the receivers, or both).
To get above the owl, we hiked higher than we needed to; it is easier to locate an owl starting out from a higher elevation than the owl to avoid the signal bouncing off the walls of a steep hollow, and being inhibited by the "shelves" that make up the slope. As we approached the area where we figured the owl should be, based on our readings from farther away, the signal faded away, as did the "bars" on the receiver (the signal from the owl's transmitter comes in as a "pulse" through the receiver, and this pulse can be monitored by sound, or visually through bars that continually fluctuate based on signal strength).
We were about to give up, when we both decided to start searching a nearby pitch pine. I was extremely doubtful that we would find her, but sure enough, we saw her little round body shining in the sun almost 60 feet up in a pitch pine. Thanks again to Carl for helping me hunt her down!
Next, we set out to track Gemini, who has taken up residence for over a month near Pine Grove Furnace State Park. There were no "beeps" to be heard anywhere near her usual haunts by Tom's Run. I last noted she was present on the 18th, and it is likely she left the area in anticipation of the few inches of snow that fell on the 19th. Maria also seems to be gone, and has not been located in her typical area since the 13th. The owls may have found a nearby hollow to roost in, or may have moved on further south, continuing their migrations. We will spend the next few days trying to relocate them.
Lexi's unusual roosting habits
Above: Lexi roosting on a dead branch (Photo: George Gress)
Left: A typical chestnut oak/pitch pine dominant roost location (Photo: George Gress)
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.
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.
Wednesday, January 14, 2009
Wandering wings
Lexi, with a bag lunch (©Anna Fasoli)
What I love about this project is the way the owls keep surprising us -- even if it is occasionally inconvenient.
On Monday the 12th, Aura Stauffer checked on our three tagged owls and found them all pretty much where we'd expected them to be, with Lexi and Maria roosting in the upper reaches of King's Gap Hollow. So that night Anna Fasoli, Drew Weber, Jamie Flickinger and I met to track them, hiking half a mile up to the icy ridgeline to get into good position.
Only owls had other ideas. Maria quickly moved south through the gap and into Cold Springs Hollow, while Lexi zoomed off to the north and west. We decided to chase her, hoofing it back down the mountain, figuring Lexi had shifted to Irishtown Gap Hollow, the next one to the west.
Only she hadn't; there was no sign of her signal. Drew finally located her in about the last place I'd have expected - a small patch of riparian woodland along Yellow Breeches Creek in the valley below South Mountain, a 2.5-mile flight from her roost.
We spent the next five hours monitoring her minor movements within the woodlot, all of us speculating whether the heavy ice on the ridgetop had forced her down, and wondering if she'd remain in the valley to roost the next day.
She didn't. Anna relocated Lexi yesterday, even farther up the side of Buck Ridge than usual, in a dense laurel patch Anna had to crawl into on all fours. This is the first time we've documented a nearly six-mile commute between roosting and feeding sites, a remarkable distance for a small owl.
What's more, Lexi was perched on the ground, holding half a deer mouse leftover from her nighttime hunting, with lots of whitewash on the snow around her. All saw-whets are easy to approach in daylight, but Lexi is unusually tame around us. To get these amazing pictures once she'd finished collecting habitat data, Anna held the camera just an inch or two from Lexi's face (if you look, you'll see Anna's reflection in the owl's eyes).
Concerned Lexi might become fox food if she stayed where she was, Anna poked her gently to make her fly. At first, Lexi simply landed on Anna's backpack, then finally flew a few yards to land up in the laurel.
(©Anna Fasoli)
Friday, January 9, 2009
Icy wonderland
The icy wonderland that is South Mountain...with snow on the way. (©Aura Stauffer)
Both Anna and Aura were out tracking yesterday, and between them they found all three of our telemetry owls.
Anna found Gemini in a tall white pine in her accustomed area along Tom's Run in Michaux State Forest, back near a roost she used Jan. 3. It's a stand of pines and hemlocks northeast of a small cabin that sits near the middle of her winter territory. Everything was still covered in ice, with the wind knocking some of it down; Anna said that Gemini (I keep calling it "she" out of habit, even though it's a sex-unknown bird) was fluffed up in the cold.
A little keepsake from Lexi - a fresh (and frozen) pellet, one of many we've collected and will analyze to see what the owls have been eating. (©Aura Stauffer)
Aura tracked down both Maria and Lexi, who are staying on King's Gap State Park property in upper King's Gap Hollow, as usual. Lexi was perched in a small pitch pine in the firebreak, and Aura was able to collect a pellet from below her roost, while Maria was .3 mile away, not far from the firebreak and back in the same tree she used Jan. 4, and which Quasi had used almost exactly two months earlier.
As you can see from Aura's photos, South Mountain is a real icy wonderland right now, and it may become even more of a challenge to get around after Saturday, with the prediction for 4-6 inches of snow starting tonight.
(©Aura Stauffer)
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