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.

Lexi has left the building

Lexi's moved on. (©Karl Kleiner)

Well, all good things must come to an end - and almost four months to the day since we first radio-tagged her, Lexi has left the King's Gap area, presumably heading north to breed.

Since the end of February, she'd been roosting in a small grove of white pines along Yellow Breeches Creek in southern Cumberland County, and every day or two, telemetry coordinator Aura Stauffer's been checking on her. On April 8, Aura was joined by Karl Kleiner, one of our banders who is a professor at York College of Pennsylvania, and two of Karl's students, Katie Kolos and Shawn Fauth, who tracked down Lexi with Karl and Aura's help.

Katie Kolos (left) gets a bearing on Lexi while Aura Stauffer and Shawn Fauth watch. (©Karl Kleiner)

The next day, Aura was back, realizing that with the opening of trout season, Lexi suddenly had lots of company in her streamside retreat. Aura pointed out the owl to a couple of young boys and their father who were fishing the Yellow Breeches. "One of the boys ran over to his mom, who was fishing, and told her he just saw the smallest owl in Pennsylvania," Aura reported. "How cute!"

On Saturday, telemetry volunteers Carl and Pat Leinbach, who helped so much last fall and winter with our nighttime work, checked on Lexi and found her signal right where we expected. But by Easter morning, when Karl Kleiner and Susan Klugman checked, there was only silence, and the Leinbachs found the same later in the day. Aura was out this morning, and she confirmed what we all suspected -- Lexi was finally on her way north.

"After tracking her for four months, I will miss the little bugger," Aura said. "She has given us a lot of interesting information; not to mention a whole freezer full of owl pellets (my Mom would be appalled)."

It's been a remarkable experience to track one bird for so long, and Lexi gave us amazing insights into saw-whet winter ecology and behavior. And who knows? She may end up in our nets (or someone else's) down the road. In the meantime, we all wish her a safe migration and successful first breeding season.

There's an funny coda to this story. Carl and Pat, unwilling to give up, headed out today to try one more time for Lexi's signal in some of her other previous roost areas. They started near the pine grove, then drove toward King's Gap, using the roof antenna on their car. Near the state fish hatchery -- bingo, they got a signal. After some doubling back to confirm, they raced up to King's Gap, got out and hooked up the handheld yagi antenna. Nothing, not even near the hatchery.

Then they drove up the mountain on Cold Springs Road to Ridge Road, and along the top, they got a strong signal again. Pat turned off their Prius, and Carl got out with the yagi. Again, nothing. When they hooked up the roof antenna, again they got a strong signal - and that's when they realized that the electrical system in their Prius was fooling the receiver.

"We were tracking ourselves!" Carl said. "The Prius is a small car, but hardly qualifies as a saw-whet owl."

We couldn't ask for a better, more dedicated crew of volunteers - and now, with our two-month "autumn" research season finally wrapping up after almost seven months, it's time for us to take a rest. Thanks as well to those who've been following this blog - we'll start again come late September, with more banding, telemetry and an even more exciting new project...but we'll have more to say about that come fall, though.

Lexi's Big Day

(©Aura Stauffer)

Aura Stauffer checked on Lexi today, and found her back in her favorite spruce tree; here's a photo of her there last week in that tree, enjoying some early spring sunshine.

And here's a shot of the woman who is often behind the camera - Aura with Lexi, right after giving the young lady a new radio transmitter last week. The photo's courtesy of DCNR botanist Carrie Gilbert, who was kind enough to give Aura a hand in capturing and reharnessing Lexi - you need a minimum of four hands for the job, and while Aura's amazing, there are limits to what she can do alone.

Aura Stauffer and Lexi (©Carrie Gilbert)

A Most Excellent Owl

Lexi, enjoying a mild spring day. (©Scott Weidensaul)

Although I haven't posted an update in a while (I was away much of late February and early March), we're continuing to keep tabs on Lexi, that most obliging of saw-whets, who has broken all our records in becoming by far the latest-lingering telemetry owl in the eight years of this project. The previous late date for a tagged saw-whet was Feb. 21, and we're coming up on a month past that point.

I checked on Lexi yesterday, March 14, as we've been doing every day or so, and found her still roosting in a white pine thicket along Yellow Breeches Creek, about three miles northwest of the ridgetop portion of King's Gap State Park she'd used in December and January.

Last week, Aura Stauffer realized Lexi's radio signal was getting weaker - it had been almost exactly three months since we'd tagged her, and the batteries only have an expected life of 90 days. On Wednesday, Aura took advantage of Lexi's low roost to get a stepladder and hand-grab the little girl - such docility and tameness is typical of saw-whets, and Lexi in particular. Within a short time, Aura had replaced Lexi's radio with a fresh transmitter, so we should be able to keep up with her until she finally decides to head north.

When will that be? Frankly, I'm quite surprised it hasn't happened already. The peak northbound migration is usually around the beginning of March, based on our limited spring netting in years past, and we've had some perfect migration nights with warm temps and southerly winds. On the other hand, Lexi is a young bird, born in 2008, and doesn't have an established territory to which to return; adult birds of most species migrate more rapidly north in the spring than juveniles.

We're continuing to share Lexi with visitors. Last weekend, Aura took the 26 members of the Governor's Youth Sportsmen Advisory Council (who were meeting at King's Gap) to track her, and yesterday I had Hillel Brandes and Doug Miller of Penn State with me. Doug is the co-director of the university's office for remote sensing and spatial information resources, and he has some great ideas of how to combine extremely high-resolution mapping imagery with our telemetry data so we can better understand why the saw-whets are choosing the roosts and habitats that they use.