Too busy to write

George Gress banding a saw-whet at Hidden Valley (©Scott Weidensaul)

It feels as though we've gone from 0 to 60 around here in no time flat. After a miserable weekend Oct. 15-17, with tons of wind-driven rain, and some snow at the higher elevations, the skies cleared out Sunday, Oct. 18 and we started catching owls - 32 that night, 17 of them at Hidden Valley alone.

All three sites are attaching geolocators, and we've deployed about 30 of the 190 we need to send out this fall. And we've radio-tagged two more saw-whets, which the crew nicknamed Elvira (a hatching-year female) and Isra (a second-year female). Xena, which was tagged Oct. 12, seems to have left the area, but Skreech the screech-owl remains on its territory near King's Gap.

Thank goodness for Skreech. Last weekend, as the worst of the weather was descending, our colleagues Nick and Mary Freeman, who study breeding owls (including saw-whets) in the mountains around Los Angeles, flew in from California. Their first night of banding was canceled due to rain, and Saturday night we were determined to get them out for radio-tracking - except that Xena had bugged out in the rain the night before.

So it was Skreech to the rescue. For three hours in clammy mist and occasionally heavy rain, we gave Mary and Nick a tutorial in basic radio triangulation techniques, along with tips on getting your data sheets soaked, holding dual umbrellas to shield the tracker, and avoiding drips of icy, barely-above-freezing rain down the back of your neck. Mary asked, "Is Pennsylvania always butt-freezing cold?" At this time of the year, often.

Fortunately, they were still in town the next day when the skies cleared and north winds began to blow. They had a few great hours of hawkwatching at Waggoner's Gap, then joined us at Hidden Valley for our 17-bird night.

Since then, the weather has grown considerably less butt-freezing, and with Indian summer, not surprisingly the number of owls has dropped off, down to five to eight per site each night. Still, we're up to 75 for the season - below average but making up ground rapidly.

Tuesday night the telemetry crew were chasing Isra up in Michaux State Forest. Between the canopies of the trees, they could see patches of star-splashed sky - and the whizzing, bright trails of the Orionid meteor shower, which graced the final hours of the night before they put Isra to bed, and went off to get some sleep themselves.

Geolocators

Although a big nor'easter storm has temporarily shut us down, we had an exciting couple of nights before the rain and snow hit. Drew, Kim and Hannah have been tracking Xena and Skreech as they hunt the woods near King's Gap. On the banding side, while the number of owls remains quite low for this time of year - just 10 saw-whets and two eastern screech-owls - we've begun deploying the light-sensitive geolocators we're using this season to study their migration.

A light-sensitive geolocator, which weighs about 2.5g (©Scott Weidensaul)

The geolocators are miniature, backpack-mounted data-loggers, continuously monitoring light levels for up to two years, from which we can determine the rough latitude and longitude of the migrating owl. The tiny units are custom built by the British Antarctic Survey, and have been used to study the migrations of wood thrushes and purple martins, but never saw-whet owls.

This week we began fitting saw-whets with geolocators at our Hidden Valley station, and will soon be doing so at all three of our sites. The harness is made from thin, tough Teflon ribbon that figure-eights around the bird's body, holding the geolocator high in the middle of the back. A short stalk sticks up above the feathers, with the light sensor at the tip. The entire unit and stalk are encased in a light, thin shell of epoxy to protect the innards from sharp owl beaks.

A saw-whet, fitted with a geolocator and ready to go. The sensor stalk protrudes an inch or so above the feathers on the back, continuously recording daylight and darkness. (©Scott Weidensaul)

(A special thanks to Marge Gibson and her staff at the Raptor Education Group in Wisconsin, who tested the geolocators and the harnesses on three of their captive saw-whets, even going so far as to create nest boxes with natural flicker- and pileated woodpecker-sized entrance holes, to make sure the sensor stalks didn't interfere with the owls' ability to enter and exit the cavities.)

We were also grateful to York University grad students Maggie McPherson and Callie Stanley for giving up their (Canadian) Thanksgiving holiday to come south to help with the work, and to give us the benefit of their geolocator experience working with thrushes and martins under Dr. Bridget Stuchbury.

From left: Callie Stanley, bander Nate McKelvie (front), Maggie McPherson, Pat Trego (rear), Nada Farah, Baha' Ishaq (rear), Ika Rani Suciharjo and Maria del Mar Contaldi. (©Scott Weidensaul)

Finally, we were delighted this week to welcome a number of the international interns from Hawk Mountain Sanctuary, which is not far from Hidden Valley. Marie del Mar Contaldi from Argentina is working on a master's on vulture and condor biology; Nada Farah from Lebanon serves as the country's Important Bird Areas coordinator; Baha' Ishaq from Palestine is an undergrad at Bethlehem University and the only licensed ringer (bander) in the Palestinian territories; and Ika Rani Suciharjo from Indonesia is a high school biology teacher with extensive experience in environmental conservation. As you can see from the picture, they were thrilled with their first encounters with saw-whets.

Xena, visitors, and better things to come

Well, things are started to click along down here, slowly but surely - and it appears the flood gates have finally opened to our north, promising better owling to come.

Although we only caught two saw-whets Monday night - one at Small Valley and one at King's Gap - the latter bird, an immature female, left with a radio transmitter and a nickname that intern Hannah Panci came up with - Xena, for the TV warrior princess, in recognition of this little fighter's spirit. From her release until about 3 a.m., Xena stayed on the ridgetop near the banding station, then moved down the west side of the mountain, staying put until the tracking crew left her at 7:30 a.m.

Although we didn't have any owls at Hidden Valley, we did have a couple of interesting guests, who will be with us all week. Maggie McPherson and Calandra (Callie) Stanley are grad students at York University in Toronto, studying with Dr. Bridget Stuchbury, a specialist in songbird migration, and one of the first scientists to use geolocators like the ones we'll be deploying this fall.

Maggie and Callie are both working with wood thrushes and purple martins at Bridget's study site in northwestern Pennsylvania, and Callie is also tagging thrushes on their wintering grounds in Costa Rica. They've given up their fall break to drive down from Toronto and spend the week helping us with our geolocator work - and spend some time with owls, since Maggie began banding NSWOs in ninth grade in Ontario, working the Timiskaming stations run by Bruce Murphy.

Speaking of whom, Bruce posted a happy warning to those of us to the south that the wait may soon be over. Friday night they had 95 saw-whets, one of their biggest nights ever, although high winds have cut their catch rate since then. They're up to 390 for the season, and he thinks we in the south will have the roughly average flight I've been expecting this year, which for our sites would mean around 450-500 owls.

Slow going

The banding stations have been open for a week, but in that time we've netted just a single saw-whet, caught Oct. 5 at our Hidden Valley site - one of the slowest starts we've had in the 13 years we've been studying owl migration.

Part of the reason may lay with the relatively mild, windy, showery weather we've had here in the mid-Atlantic, but I suspect even more of the problem lies to our north - a series of storms that have paraded across southeastern Canada, slowing down the migration.

However, there's a dramatic change in the weather coming over the next few days, with an Arctic air mass plunging down through the Great Lakes and East, with predictions of snow downwind of the lakes and on the higher elevations of New England. We're expecting this cold snap to generate the first good push of owls in our region, perhaps as early as tonight.

Meantime, our radio-telemetry crew has been focusing its attention on the screech-owl we tagged last month, and they're taking a weekend off after six nights of triangulation. Skreech, as they nicknamed the bird, has been hunting the western side of King's Gap State Park and adjacent portions of Michaux State Forest, moving around frequently enough to keep Drew, Hannah and Kim on their toes. Once we start getting saw-whets, they'll switch their attention to them, but we'll continue to keep track of Skreech in the weeks ahead, too.

Skreech and the full moon

"Skreech," the first of this year's owls to be radio-tagged. (©Hannah Panci)

Poets, lovers and songwriters like full moons. Owl researchers, not so much.

For whatever reason, the number of owls caught drops dramatically during a full-moon period, which may explain (along with the lovely, mild weather) why we're 0 for 4 with saw-whets - having opened our 2009 banding operation four nights ago, we still have yet to net our first saw-whet owl.

This isn't unusual - it's often pretty slow the first week of the season, and the migration doesn't peak until about Halloween. In each case, though, the crews at our three sites had plenty to divert to their attention, even in the absence of owls. At Hidden Valley Saturday night there was a fireworks display in the valley, while at Small Valley (where the caretaker has been seeing three large black bears) the volunteers were just glad nothing went bump in the night.

At King's Gap, we actually did catch an owl last week - not a saw-whet, but I'll let Hannah Panci, one of our research interns, pick up the story:

"Meet our red-morph eastern screech-owl (a hatch-year bird, sex unknown), given a gangster name of “Skreech.” After many tries over the course of three nights, Scott, Drew, Kim and I managed to lure it into the net last Wednesday night. Fitted with the newest model of radio transmitter backpack, it was released, and our little research team tracked it until 3 am. We found it again yesterday, sneakily roosting in the open about 30 feet off the ground. We’ll be tracking Skreech throughout the fall, both as telemetry practice and to see how its movements may affect any tagged saw-whets we are following. So look for more updates!"

That's Hannah's photo of Skreech, which we aged as a hatching-year bird - meaning it was born earlier this year, and is entering its first winter - by looking at its feather molt, and the pattern of pale scalloped markings on its primary wing coverts, among other clues. Unlike the migratory saw-whets, we're expecting Skreech to stay fairly close to its banding site on top of South Mountain, although as a young bird, it may still be drifting about, trying to establish a permanent territory. Once it does, though, the bird should sink down roots and stay put for the rest of its life.

Reptilian preview

Trying its best to be unseen, a timber rattlesnake trusts its camouflage. (©Scott Weidensaul)

Yes, I know this blog is about owl research...so why is that timber rattlesnake staring at you?

Last week, our 2009 research crew arrived and started training - and part of their training regimen was two days of radio-tracking rare timber rattlers on South Mountain, the same area where they'll be tracking owls. Last Thursday morning we joined state DCNR biologist Aura Stauffer (also a longtime volunteer member of our banding crew) to seek out several of the rattlers that the state tagged with implanted radio transmitters this summer.

Eastern timber rattlers have been on the ropes for years, with habitat fragmentation and persecution sadly reducing the population of this shy, docile reptile in Pennsylvania, to the point where it's a candidate for state endangered species listing. (There's more information about their ecology and status here.)
The South Mountain population is especially threatened, surrounded as it is by a sea of agriculture and development.

Aura led research tech Drew Weber, interns Hannah Panci and Kim Romano, me and my 15-year-old nephew Connor (who has helped with our banding and tracking since he was little) up into the rain-damp woods. Hannah, who is new to telemetry, took the receiver and yagi antenna, and with Aura's help directed us up through thick oak and pine woods with a dense understory of mountain laurel. This late in the season, Aura was expecting the snakes to move from their foraging areas to near their hibernacula - the winter den sites whose locations are unknown, and a major focus of the study.

The signal beeped more and more loudly, and Aura announced that we were getting close. Although we were all (except Aura) wearing bite-proof leggings, we watched our feet, while Aura used her snake hook to knock down some greenbrier vines. We paraded single file uphill, but just as Hannah stopped, turned, and said, "I think we walked past it," Connor gasped and pointed at Drew's feet.

The rattler, a large dark-morph male, was less than a foot from Drew - but typical for the species, it never rattled or showed the slightest aggression. Neither did the next one we tracked, which was a few hundred meters away, or a third that Kim found around lunchtime, a stunning yellow-morph female (above) curled up in the sun in a recent timber cut, even when I was lying two feet away for a better camera angle. Aura's stepped directly on rattlesnakes a few times and not been bitten. If only people showed as much tolerance for rattlers as the snakes do for people.

The highlight of the day, however, was the last stop, a small rock field deep in the woods. Walking in while Drew tracked the signal, I all but stepped on an untagged rattlesnake that did give a warning buzz as it slid down a chipmunk hole. Then we began to walk carefully up the slope of the rocks, where Aura pointed out five or six females and 14 newborn babies, known as neonates.

Suck rock fields are rookeries - sites where gravid females gather all summer to bask in the sun, not eating, only moving from sun to shade to keep their internal temperature perfectly balanced for the growing embryos. Then each female gives birth to about half a dozen babies around Labor Day, and the family remains together for a short while.

Only a few weeks old, a baby rattler surveys a hostile world (©Scott Weidensaul)

Rookery rocks are one place where rattlesnakes buzz more often than not, and the rocks were alive with the cicada-like rattles. The adult females slid underground quickly, just poking out to look at us, but the babies were curious, sometimes coming closer for a better look.

The reproductive cycle of the timber rattlesnake is glacial. A female mates one year, gives birth the next, and may have to take a year or two off before mating again to rebuild her energy reserves. A Pennsylvania rattler may only reproduce a couple of times in her life, and at the northern edge of their range, in the Adirondacks and southern New England, she may get only one chance to give birth.

Knowing the odds arrayed against this quiet, badly misunderstood species, it was a special privilege to see so many rattlers in one day, including a new generation facing an uncertain future.

Ready, set...

Although it's been six months since we wrapped up our winter radio-tracking in April, we haven't been idle - in fact, we're a few days away from launching by far the most ambitious season of saw-whet owl research since the Ned Smith Center started studying these remarkable birds 13 years ago.

Once again, we'll be operating three banding sites through October and November - Hidden Valley in western Schuylkill County, PA; Small Valley in northern Dauphin County; and King's Gap in southern Cumberland County on South Mountain. Manning these stations will be 16 federally licensed banders and about 85 volunteers (which is a bit of misnomer; everyone on the banding crew is a volunteer).

We know from long experience that saw-whet owls are cyclical, and we're expecting a better season than last year's stinker total of 229 owls, but nothing like the record 900+ we had in 2007. I'm predicting a roughly average 475 owls, and would love to find that I low-balled it.

We also will be completing the second year of our two-year nighttime activity range study at King's Gap and adjacent Michaux State Forest. This formidable undertaking will be headed up by research technician (and '08 research intern) Drew Weber, ably assisted by this year's interns - Hannah Panci of Eagle River, WI, and Kim Romano of Lawrenceville, GA. They'll be conducting all-night radio-tracking roughly four nights a week through Dec. 18, and will be sharing their experiences through the blog.

Finally, we'll be using some of the most cutting-edge technology in avian research this year - tiny, light-sensitive geolocators, a kind of data logger invented by the British Antarctic Survey for tracking albatross migration, and now miniaturized by the BAS for use on smaller birds. (You may have seen a ground-breaking study published last winter by my colleague Dr. Bridget Stuchbury at York University in Toronto, which used geolocators to track wood thrushes and purple martins to and from their tropical wintering grounds.)

By logging daylight length and light intensity, the units record daily latitude and longitude for up to two years. We'll be deploying 190 of them this fall, and although only 10-20 of them are likely to be recovered in years ahead, those should shed unprecedented light on saw-whet owl migration. (Both the telemetry and geolocator projects have been underwritten by the generous support of the RJM Foundation, for which we're grateful.)

We'll be updating the blog every few days through the banding season, which kicks off this weekend - watch for updates, and to learn more about the project, visit the Ned Smith Center's website at www.nedsmithcenter.org.