Friday, October 31, 2008

Busy day, slow night

Despite absolutely perfect conditions, our crews managed just six new saw-whets last night - a sobering reflection of how slow a season this has been. We're at 106 saw-whets, less than half our 10-year average of 229 for the date, and 4.5 times fewer owls than the 497 we had by this date last year during the big irruption.

In fact, we've had only one season -- 2006, our Annus Horriblis -- when the YTD total was worse. That miserable autumn we had just 40 owls by now, having gone the first 24 nights with a total of five saw-whets.

So it could be worse.

Fortunately, this has been a spectacularly successful year for the telemetry program, thanks to our telemetry team of Anna Fasoli, Drew Weber and telemetry coordinator Aura Stauffer, with a bunch of great volunteers. Aura was out yesterday with volunteer Carl Juris checking on all four tagged owls. They found Morticia, the newest bird, in King's Gap Hollow -- sort of. They narrowed the signal down to a large white pine on the east side of King's Gap Hollow, but couldn't get a visual on the owl.

Aura and Carl did find Fairfield in the same general area where she's been hanging out, just north of Pine Grove Furnace State Park. Ever the cooperative little saw-whet, she was perched low in a pitch pine, and Aura got some great photos of Carl taking dbh (diameter breast height) measurements on the trees around the roost, as well as Fairfield herself.

Fairfield, wondering how the primates keep managing to find her. (Aura Stauffer)

Carl Juris collecting vegetation data (©Aura Stuaffer)

After Carl headed for home, Aura found Quasi back in her roost tree from the 27th - she's been alternating between the same two trees since she was tagged on the 26th.

Find the owl among the pine cones: Quasi on her roost, or, Why owl trackers develop sore necks. (©Aura Stauffer)

Autumn, on the other hand, was nowhere to be found. Having spent nearly two weeks in southern King's Gap SP, she moved southeast of the park below Hammond's Rocks Tuesday night, and yesterday Aura couldn't pick up her signal in that area, or back in her old haunts. Maybe she's left, or maybe she's tucked in a new hollow -- time will tell.

Thursday, October 30, 2008

Does Morticia speak French?

Despite very good conditions - cold, moonless and calm most of the night - we had another very slow evening at the banding stations. King's Gap and Small Valley each got one local recap, while Hidden Valley had a single new bird. That one, at least, broke 100 for the season.

Aura Stauffer bestowed a radio on the King's Gap recap, an SY-F now named "Morticia," in keeping with the Halloween theme. (Whether she drives her mate crazy when she speaks French, I can't say.)

Yesterday, research tech Anna Fasoli was out checking on our other three beeping birds. She found Quasi in exactly the same pitch pine as the day before, though higher in the tree and apparently sitting in a nest-like cluster of branches...another example of a NSWO using an old nest or nest-like structure, something we're documenting for the first time with our telemetry work. Fairfield was about four-tenths of a mile north of her previous location, with lots of pellets on the ground to show she's used this tree before.

Autumn moved more than two miles to the ESE, somewhere between Hammond's Rocks and Mountain Creek Road -- Anna didn't have time to hike all the way in, but biangulated her location. Aura's heading out today to check all for owls, and will start with Autumn.

We found out that an foreign owl I caught at Hidden Valley on Oct. 19 was banded Jan. 16, 2008 in Charles City County near Richmond, VA, by one of Bob Reilly's crew. And we also got word that one of the two foreign birds we caught at Hidden Valley on Sunday night was banded Oct. 13, 2007 at Drumlin Farm Bird Sanctuary, a Massachusetts Audubon facility 15 miles west of Boston near Lincoln, MA. This is the second owl we've traded with Drumlin Farm this fall; they caught one of our fall '07 Small Valley birds last Thursday.

Wednesday, October 29, 2008


The huge nor'easter that came roaring through eastern Pennsylvania Tuesday wiped out our banding, since rain, snow and 40-50 mph winds are not conducive to catching owls. Some of the higher ridgetops just north of us got walloped with 15 inches or more of snow.

Besides canceling banding, we'd planned a major night of triangulation tracking, with three teams of trackers and helpers -- all to naught. It was a good night to curl up in front of a fire.

However, despite the rain (and lots of fallen trees and falling branches), research tech Anna Fasoli was out during the day checking on our three radio-tagged owls. She found them all more or less where they'd been the day before, having moved anywhere from 70 to 231 meters.

Here's a sneak peek, though, at what we're working so hard to get this fall -- an evening activity map for Autumn, one of the King's Gap owls we've been tracking, at a previous roost she's long since left. This was from a tracking session from dark until about midnight on Oct. 19 -- the yellow dot shows Autumn's daytime roost, and the yellow X's mark the spots where Anna and research intern Drew Weber were standing, taking bearings on the radio signal from Autumn's transmitter.

The red dots are where the bearing lines intersected, giving the owl's position (the numbers are time markers - 2310 is 11:10 p.m. EST). We usually take bearings about every 10 minutes, and we try to position ourselves so the bearings intersect at roughly 90 degrees, which gives he most accurate position -- but as the owl moves that isn't always possible, and sometimes Drew and Anna were taking bearings almost directly toward each other. Those inaccurate readings aren't included on the map, which is why there are some gaps in the time line.

Still, this gives us a pretty detailed picture of her movements over the course of almost five hours, moving around the oak/black gum/pine forest on King's Gap's southeastern border. There have only been a handful of attempts to get this kind of activity data on saw-whets before -- once in the 1960s in Minnesota, using an automated system to monitor a single saw-whet in a large woodlot, and again with two breeding males in Idaho some years later. Those studies found that the saw-whets were using areas ranging from 115 hectares (about 284 acres) to 159 hectares, but also that one male's core range was only about 27 ha. (about 66 acres).

In rough terms, Autumn's activity area was about 32 hectares, or about 80 acres. This was not her full night's activity range, but probably represents her first main hunting bout, moving around looking for a mouse, then settling down to eat it. But it begins to shed some light on how large an area these birds need to hunt, and what kinds of habitat and terrain they use in doing so.

Tuesday, October 28, 2008

Bad weather, good friends

An enormous low pressure system moved in the Northeast last night, and in advance of, unexpected rain overspread eastern Pennsylvania around dark, making for a shortened night at all three sites.

Although we managed to net two new saw-whets at Small Valley, and one new bird plus a local recap at King's Gap, we were blanked at Hidden Valley, where the rain came in fairly steadily around 8 p.m., and forced us to shut down at 9:30.

Which was a shame, because we've rarely had such a firmament of banding superstars on hand. Our good friends Bob and Martha Sargent, founders of the Hummer/Bird Study Group, had driven up from Alabama, and Anthony Hill and his wife Carlene were down from their home in Massachusetts. Bob and Martha's crew conduct spring and fall songbird banding at Fort Morgan on the Gulf coast, and have been largely responsible for an extensive network of banders in the East and Southeast (including me) who band western hummingbirds wintering in the region.

Anthony is a master bander who works every summer on Seal Island, Maine, banding puffins, and on Appledore Island, Maine, each spring and fall banding songbirds. He's also been trained to band hummingbirds, and like Bob and Martha, has caught the saw-whet bug.

Despite the weather, we had a nice welcoming dinner for them at Hidden Valley, where my crew (Phil Witmer and Barb Jucker) were joined by Small Valley coordinator Sandy Lockerman and SV crewmember Shirley Hamilton, and my wife Amy. We got wet, but we ate like royalty.

Phil, Sandy, Scott, Bob, Martha, Carlene, Anthony and Amy (thanks to Barb Jucker, behind the camera).

Before the rain arrived Monday, Aura Stauffer managed to track all three of our current telemetry owls. The newest, Quasi, has moved into the southern part of King's Gap park, where she was sitting high in a pitch pine, while Fairfield has moved almost three miles of the southwest, and was in a white pine close to Pine Grove Furnace State Park. Autumn, meanwhile, was right along the King's Gap/Michaux State Forest line, in a chestnut oak growing in a heavy regenerated old clearcut off a logging road, where Aura found a pellet and lots of whitewash - evidence she's used that roost before.

Here's their current locations (note that north is to the upper right corner, the better to fit the locations into the image).

The storm is currently strengthening into a major nor'easter, with predictions of 50 mph wind gusts and several inches of snow at the higher elevations tonight. We were poised to conduct a full-court-press triangulation tonight on one of the tagged owls, but in the interest of everyone's safety, we've canceled both tracking and banding.

Monday, October 27, 2008

A windy night for Quasi

Tonight, convenience was the word. Drew and I arrived at King’s Gap around 6:30 to track either Autumn or Quasimodi (Quasi for short), the plump new owl we put a transmitter on last night. Autumn was at her usual location about 1 mile south west of the Pond Area, while Quasi was roosting in the south east section of King’s Gap Hollow. We chose to track Quasi, hoping she would stay in the vicinity of King’s Gap to use the roads to our advantage. Initially, it appeared as though Quasi moved north east of her roost a short distance of about .2 miles. As Drew and I figured out the best locations to biangulate by 8:00 pm, she seemed to move slightly down slope and to the west, just a few hundred meters from her roost location. For the next few hours, Quasi was quite boring to track. In the world of owls, this translates to catching, tearing in half, eating, and digesting a mouse. We noticed slight fluctuations in the location of her signal during this time (through midnight), but this may have been attributed to the gusty winds. Wind can move the trees between trackers and the owl, including the branch the owl is on, causing these fluctuations, despite a lack of movement by the owl off her branch. The movements were so small that we had no way to distinguish them between (slight) real owl movements, and interference from wind. However, we can make a good assumption that Quasi was not actively hunting at the time, and most likely had a mouse.

Because Quasi did not move very far away, Drew and I were able to track from the comfort of our vehicles. The curves of King’s Gap road allowed us to surround her while being able to stay on the road, to use an angle of about 90 degrees to pinpoint her location. This is the first night we’ve tracked from our vehicles. On our other night time adventures, we trudged through the woods to find the best vantage points. While both methods work the same, I must admit that sitting in a vehicle alone is slightly more appealing that sitting in the woods alone. Even better, I was able to plot our readings on my computer to see how they were intersecting. At around 11:00 pm, Quasi had still not moved, so we triangulated her position. This is similar to a biangulation, but instead of just two readings from two different locations, we added another. I drove to a third location shortly after we simultaneously took the first two. Because Quasi was not moving at the time, this worked well, and we were able to get a more exact location on where she had been chowing down on her mouse. We’ll head out again tomorrow night with a few new volunteers to see what Quasi or the others are up to.

Susan Klugman and Karl Kleiner relocated Fairfield today in Michaux State Forest. We had previously thought she left when we didn’t find her 2 days ago at her favorite mountain laurel patch. Now we’ve got 3 beeping owls in the area, which will give us many good options for night tracking over the next two nights.

Sunday, October 26, 2008

A Wet Night

A powerful storm took its time leaving the midstate Saturday, delaying the opening of King's Gap and Small Valley, and canceling banding entirely farther east at Hidden Valley. Nevertheless, we banded one saw-whet at Small Valley and two more at King's Gap, including a second-year female fitted with a radio transmitter. Since she sat hunched in the hand, the crew named her Quasimodo -- "Quasi" for short.

Earlier in the day, research tech Anna Fasoli looked in vain in the downpours for Fairfield, the owl with a liking for laurel tangles. It may be that she's just hidden in some hollow that deflected the radio signals, but it's more likely she left in advance of the storm. Anna was able to locate Autumn, still about a mile and a half southwest of King's Gap in Michaux State Forest.

We're gearing up for three back-to-back nights of triangulation telemetry, which will be challenge with the forecast of high winds tonight, and sharply colder temps the rest of the week. There's also a chance that the cold front might prompt one or both of our remaining tagged owls to leave -- we'll just have to see what happens. Banders Karl Kleiner and Susan Klugman plan to celebrate their wedding anniversary today by roost-tracking both owls, then tonight, Anna and intern Drew Weber will try to follow one of the saw-whets.

Friday, October 24, 2008

Dots on the map

We keep putting along here this fall - no huge numbers, but enough to make it worthwhile to stay up in the cold.

Small Valley was the hot spot last night, with six new owls including another foreign owl. Three new birds at King's Gap, and two more (including an hatch year male) at Hidden Valley, to the delight of 10 visiting schoolkids from the Philadelphia area.

That makes 83 for the season, and if it seems slow, I'd point out that by this date in 2006 we'd caught a grand total of five saw-whets, at all three sites combined. Now that's slow. (Yeah, I know...last year by this date, the big irruption had brought us 282 saw-whets. Such are the realities of studying a cyclical migrant.)

On the tracking front, yesterday Jamie Flickinger checked on Fairfield, who remains in her Impenetrable Forest of laurel on Michaux State Forest, not having shifted much from the past several days. Jamie didn't have a chance to check on Autumn.

There was no information yet on the foreign owl from Small Valley when I reported it online to the Banding Lab today, but we did learn that the foreign NSWO caught Oct. 17 at Hidden Valley was banded by our colleague Glenn Proudfoot exactly a year earlier, Oct. 17 '07, at the Mohonk Preserve in the Shawngunk Mountains of southeastern New York.

We've also had three encounters with our own birds elsewhere this week. On Wednesday night, an owl banded Oct. 18 at Hidden Valley was recaptured at a new banding site near Sperryville (Rappahannock Co.) Virginia, about 170 miles to the southwest, and on the east slope of the Blue Ridge Mountains near Shenandoah National Park. Here's a map showing the distance between the sites.

Such "direct recoveries" within the same migration cycle are always interesting, since they can shed light on flight routes and timing; I wonder whether this bird traveled along the ridge-and-valley system into western Virginia before jumping across the Shenandoah Valley to the Blue Ridge, or if it crossed the valley near Carlisle, PA, and headed down the northern terminus of the Blue Ridge past King's Gap and the Lamb's Knoll saw-whet station in the Catoctin Mountains of Maryland.

Also reported to us were two fall '07 Small Valley birds, one banded 10/10/07 and recaptured near Elkins, VA on Monday night, and a saw-whet banded Oct. 8 '07 and recaptured last night at Drumlin Farm Wildlife Sanctuary near Lincoln, Mass.

Wednesday, October 22, 2008

Miss Fairfield is ready for her close-up

I'm a bit behind with this, since Anna's already posted her tracking report for the day, but yesterday was also a good day for tracking owls - even with a TV crew in tow.

On Tuesday Aura Stauffer, Anna and I, along with King's Gap park director Scott Hackenburg, took Rob Dixon of WHTM-27, the ABC affiliate in Harrisburg, out to find Fairfield.

While we were grateful that our two tagged owls were still around, I'm sure Rob and his cameraman were wishing the one we picked to track hadn't been playing hard-to-get, since Fairfield was hanging out in the same dense laurel thicket just over the line in Michaux State Forest she's been so fond of lately. We thought from the signal she'd moved down the mountain, but it was actually a long climb for them, lugging a huge video camera and 40-pound tripod (which Scott H. carried most of the time).

Aura explains why sane people follow small owls (©Scott Weidensaul)

Anna and Aura were doing the tracking, thrashing through the 10-foot-high laurel. Aura, waving her yagi antenna, had just said, "She's got to be right here somewhere," when Anna, about 10 feet away, gasped and pointed - basically at Aura's head. In between the two women sat Fairfield, at head-height in a laurel thicket.

The cameraman got some terrific footage of her, and Rob's report aired a few hours later. You can see the video here.

Rob Dixon, reporting from one place he (and his cameraman) probably never thought they'd wind up. (©Scott Weidensaul)

Fairfield, who must be getting used to the attention (©Scott Weidensaul)

Aura, collecting data the only way you can in this kind of stuff -- completely prostrate. We will do pretty much anything for this project. (©Scott Weidensaul)

Settling in

Today, I set out with Alex, a dedicated telemetry and banding volunteer, to find our two King's Gap owls, Autumn and Fairfield, who are still residing in the area. Both have really "settled in" to specific areas. We found Fairfield very close to the area she has been using since October 19th, so it was no surprise that we had to fight through the mountain laurel bushes yet again. As I narrowed down the search to a small area with the telemetry equipment, Alex scanned the tall pitch pine in the center of the area, and quickly spotted her. As usual, she had spotted us first, and was staring down at us. This time she was about 50 feet up in a pitch pine, unlike yesterday, when she was just 5 feet off the ground in a moutain laurel!

Next, we headed towards Autumn's location, about one mile west of Fairfield's roost. On sunday night, Drew and I tracked Autumn for 5 hours, along with volunteers Alex and Mark, who had helped us track Dizzy while she was at Weiser State Forest. This was our first night of tracking at King's Gap this year, and it went very well. Autumn stayed within about 1/2 mile of us, as we positioned ourselves on the two hillsides that surrounded the hollow she seemed to be focusing activity in. As with Dizzy, we had problems with signal bounce, but were still able to see periods of movement, and periods of rest. We ended around 11:30 pm. By the next morning, Autumn had settled in about 1/2 mile west of the area she focused her night time activity in. Drew and I pinpointed her location, but just couldn't get a visual on her in the extremely tall red maple tree she decided to roost in. Today however, Alex and I found her with no problem. Before I could even pinpoint the tree she was in with the telemetry equipment, Alex had spotted her about 35 feet up in a pitch pine, her tail feathers just visible in the fork of a branch. Alex observed her picking at her transmitter briefly, but everything looked to be in place as she sat contently in the tree.

So far, both of our owls have been incredibly cooperative, and are settling in quite well at their "favorite" spots. We plan to do night telemetry this sunday, monday, and tuesday nights, depending on the weather. From this we will be able to see how these owls' roost locations compare with their activity ranges at night, something we hope to learn much more about this season.


With the high winds last night, we had no luck catching any saw-whets at any of the banding sites. The winds were howling at Small Valley but due to the geography of the area, the nets were not affected by the wind. The only owl of the night was a single red-morph Eastern Screech-Owl that we found in the nets during the first net check. I am always amazed at how bright red this morph is.

We don't get very many screech-owls so it is a fun challenge to age them. One thing we looked at last night was the outer primary covert (the feather my thumb is pointing at in the picture below). Because this screech-owl hatched this year (HY), the feather is strongly patterned. Older birds have a less obvious patterning on this feather. The screech-owl was the largest bird I have ever had to hold in the "bander's grip" (picture below) and it was actually too big for the bander to hold in this position.

Another feature we looked at was the age of the flight feathers. Under a blacklight, feathers of the same age turn uniformly pink. More about this effect in a later post, but basically since our screech-owl just hatched this year, all the feathers are the same age.

We ended up closing the nets an hour early because the wind was picking up and starting to blow the nets around as well as drop lots of leaves into the nets.

Monday, October 20, 2008

Trading Places

Fairfield -- no, really it is. (©Aura Stauffer)

The old real estate adage tells us it's "Location, location, location." Must be the same for saw-whets, because our two radio-tagged owls have shown a startling fondness for the same spot, out of the huge area encompassed by King's Gap State Park and Michaux State Forest.

Last week we radio-tagged two female saw-whets, which we nicknamed Autumn and Fairfield. Friday morning, research tech Anna Fasoli found Autumn roosting very close to our banding station on top of the mountain, while Fairfield was down the slope near one of the day use areas, perched in a grove of white pines.

All well and good. The following day, King's Gap coordinator Gary Shimmel and telemetry guru Aura Stauffer headed out to check on the birds. Sure enough, they got a strong signal from the day use area, and found that Fairfield had moved across the road into a chestnut oak. The other owl was higher up the mountain -- more about her in a sec.

Then on Sunday, it was my turn to do daytime roost tracking, and once again, I found Fairfield at the day use area...but when, after collecting all the habitat and vegetation data we need, I double-checked the transmitter frequency, I discovered we'd been making a mistake the past two nights. The owl sitting in the pine trees wasn't Fairfield, it was Autumn -- they'd switched places.

In fact, the pine that Autumn was in was less than 15 feet from the one Fairfield had been using two days earlier. Was this merely some weird coincidence, or is there something that makes a particular grove of pines - out of uncounted pines in the area - attractive to a saw-whet owl? That's one thing we're investigating.

The real Fairfield was roosting Sunday about three-quarters of a mile away, in a hellishly thick mountain laurel jungle on the side of a rocky slope; the last 30 yards I basically followed the radio signal on my hands and knees. She was perched in a half-dead pitch pine, but the day before, Gary and Aura had found her nearby, perched just a few feet off the ground in mountain laurel.

As with most saw-whets, Fairfield was amazingly easy to approach, as the photos show.

Gary Shimmel and Fairfield (Gary's sitting on the ground) (©Aura Stauffer)

After collecting the habitat data for the site, Gary simply picked up Fairfield, checked to make sure her transmitter harness wasn't causing any problems, and returned her to the perch. Nor is this the first time we've been able to pick up a tagged saw-whet when it's perching low; they are a famously docile and naive species.

(©Aura Stauffer)

On the banding front, we had a pretty good night Sunday. I was banding at Hidden Valley, and my crew had 11 new saw-whets and a local recap, which delighted the visiting Briar Bush Nature Center folks from near Philadelphia. Only two saw-whets at Small Valley, but another six at King's Gap.

Anna, research intern Drew Weber and a couple of volunteers did night-tracking of Autumn Sunday night, but I'll let them post about.

Saturday, October 18, 2008

First push

I had a feeling that the strong northwest winds on Friday, which produced heavy flights of Canada geese and hawks during the day, foretold good things for our banding crews. And sure enough, the winds fell to a frosty calm after dark, producing perfect conditions.

At King's Gap, Aura Stauffer's crew banded four new saw-whets, while at Hidden Valley, Jan Getgood and her crew had eight more NSWOs and a single red-morph eastern screech-owl (EASO). We usually catch a few screech-owls each season, more by accident than anything else, and while they're an interesting change of pace, the banders don't especially like them; unlike well-behaved saw-whets, the EASOs usually defecate freely and repeatedly while being handled, probably as a way of deterring predators. The stuff is slimy, brown and very smelly. "I had three layers of screech owl crap on me," Jan complained in her report.

That brings us to 27 saw-whets for the season. Tonight should be another great night, but unfortunately, two of our sites will be closed -- Small Valley because Girl Scouts are using the camp this weekend, and King's Gap because there's a wedding and reception on the property.

Aura and KG site coordinator Gary Shimmel will be out today looking for Autumn and Fairfield, the two newest telemetry owls. More news as we get it.

King's Gap first 2008 telemetry owls

Yesterday I located our two owls that were equipped with radio transmitters by Aura Stauffer Thursday night at King’s Gap. The first was roosting in a white pine just off a trail that leads to the Pond Area from the parking lot. A nearby group of children from Fairfield Middle School left just as I spotted her, but not before Kim of the DCNR staff at King’s Gap explained to them that I was tracking a very small secretive owl. Stephanie, also of the DCNR staff at the park, suggested we name the owl “Fairfield” after the school group. As I was collecting habitat data on Fairfield, she dozed in and out of sleep, and sometimes watched me intently. Again, as with Dizzy, I witnessed an aerial attack on the owl. It started with one small chickadee, and soon, at least 25 songbirds descended on Fairfield for about ten minutes. This is something the owls must get used to when they pick a more visible roost location.

From Fairfield’s location, I heard the faint “beep” of our second owl. I headed up King’s Gap Road, and didn’t have to go far to narrow down her location. She was less than a quarter of a mile east south east of the net lanes on the steep south facing slope of the hillside in a very tall pitch pine. It was a brisk fall day, so I named this one “Autumn.” She was much higher up than that last owl, and barely looked at me as I circled her.

Hopefully these two new birds will stay in the area long enough for us to collect data about both their roosting locations and their night time activity ranges at King’s Gap.

Friday, October 17, 2008

Dizzy's gone, but new owls are beeping

Well, the change in the weather brought a little improvement in our fortunes - along with a lot of leaves in the nets. Although Small Valley didn't catch any owls, they heard NSWO (that's the banding code for northern saw-whet owl) vocalizing in the woods. Hidden Valley had one (plus a big tear in one of the nets, courtesy of a passing mammal) while King's Gap snagged two new birds, both adult females, and both of which left with radio-transmitters.

That brings us to 15 saw-whets for the season. Last year at this time, during the huge southward irruption of saw-whets, we'd already caught 155 owls, but we're also well below our 10-year average for the date of 50 NSWOs. The warm weather really slowed things considerably, but I'm confident that will now change, since we're looking at blustery northwest winds and nighttime lows below freezing the next few nights.

It's a good thing we have two new birds with radios, because it appears Dizzy has finally flown the coop. Anna Fasoli and I got to Wolf Pond Rd. at 6 p.m., but there was no sign of her signal; we quickly walked in to the old roost site, checked, then split up and drove the middle and perimeter of the whole Haldeman Tract/Broad Mountain/Small Valley/Berry Mountain area without finding her. After Anna and I split up, she continued to track through Clark's Creek Valley and west of the Susquehanna on her way home to Carlisle, but came up empty.

Anna will be out today to locate the new owls' roost in King's Gap or Michaux State Forest, and we'll be doing daytime and nighttime tracking this weekend.

We received news this morning that another of our spring '08 owls was recaptured at a familiar place - Hopkins Memorial Forest in extreme northwestern Massachusetts, at Drew Jones' site run by Williams College. This is a that was banded March 2 at King's Gap, and is the second spring KG bird to show up at Hopkins this fall.

While I was repairing the torn net at Hidden Valley this morning, the woods were full of flocks of migrating robins, the air was full of falling maple and black gum leaves on the stiff breeze, and the sky was absolutely alive with big flocks of Canada geese. Those are all signs that we should see a change for the better in our owl numbers.

Thursday, October 16, 2008

Nighttime doings

Dusk in Weiser State Forest (©Scott Weidensaul)

The warm weather has absolutely killed the saw-whet migration, with no birds netted the past three nights. But we're making great progress on our nighttime radio-tracking, thanks to Dizzy, who remains a very cooperative owl.

At dusk Wednesday evening, research tech Anna Fasoli and I met up on Wolf Pond Road in Weiser State Forest, in northern Dauphin County, about half an hour north of Harrisburg, and a few miles north of our Small Valley banding site. Dizzy, who was apparently on or near the same roost she'd used the previous day, was coming off her roost as we headed into the woods at dusk, and for the next hour we followed her as she moved back and forth along a south-facing slope.

We walked back to the cars at 8 p.m. to meet longtime volunteer Alex Lamoreaux, now a freshman at PSU Mont Alto, and his college buddy Mark, and from then until 11:15 p.m. we continued to track Dizzy's movements within a fairly small area east of Wolf Pond Road, along the same slope.

Biangulation was made easier by the presence of a couple of old logging roads that allowed us to bracket her, and made harder by the dense laurel understory, which really blocked a lot of the signal, especially for Alex and me in the downhill spot. But we took bearings on 16 or 17 different locations, usually at 10-minute intervals - the first time we've been able to put our theory into practice, and it worked reasonably well.

We'll be tracking Dizzy again tonight, while Aura Stauffer will be on call to tag one or more new owls at King's Gap this evening, or tomorrow when Aura's banding. Once that happens, we'll probably shift our telemetry focus to Michaux State Forest.

Best of all, I expect that the cold front passing through right now, flinging maple leaves past my office window, will push our first significant flight of owls south. Temps this weekend are supposed to be 20 degrees chillier than yesterday, and that should act like a big push-broom, herding the owls south. We're more than ready.

Wednesday, October 15, 2008

Dizzy still in area

It was another unusually warm autumn day at Weiser State Forest yesterday as I set out to locate “Dizzy,” the saw-whet we caught October 5 at Small Valley. I did not pick up her signal near the Small Valley banding station, where she roosted on October 7, so I drove northeast through the state forest towards her last known roost location.

On October 11, Scott and I located her on roost just north of Wolf Pond Road. Today, I drove past this location to a nearby vantage point. I did not pick up a signal north over the valley, so I headed back to where I came from. As a turkey ran out in front of me, I stopped the vehicle, which decreased my background noise just enough to hear the faint “beep” of Dizzy’s transmitter off in the distance through my roof antenna. I hooked up my receiver to my folding “handheld” antenna, which indicated Dizzy was southeast of me.

I found her soon after at the top of a black gum tree, just three quarters of a mile east north east of her previous roost location on October 11. I couldn’t actually see her, but her signal was localized in a raptor nest about 30 feet off the ground. Saw-whets have used similar abandoned nests for roost locations in the past, but according to Scott Weidensaul, nothing in the literature suggests this has been observed elsewhere. As I was collecting habitat data, six titmice flew in and were quite upset to find Dizzy, but did not stick around very long. This roost location is about 2.5 miles north east of the Small Valley banding station.

It will be interesting to see her roost movements in the next few days as temperatures drop, which may encourage Dizzy to continue her migration. On the other hand, Dizzy may choose to spend the entire winter in this area. We will continue to monitor her roosting activity as long as she stays in the area, and in the meantime, we will continue to patiently wait for more owls to arrive at King’s Gap. Again, last night the moon was too bright and temperatures were just too warm, and no owls were caught at any of the three sites.

Tuesday, October 14, 2008

Better than TV on a slow night

The mild weather finally caught up with us Monday night, with no owls at any of the three stations, although the Small Valley crew heard a saw-whet mewing near the nets.

Alex Lamoreaux, who started banding at Hidden Valley at age 11 and who now, as a college student, is helping out at King's Gap, got these photos of a southern flying squirrel that was racing around the banding site all evening, keeping the crew entertained. Flying squirrels are almost as cute as saw-whets -- but not when they get into our nets. This one was well-behaved.

Monday, October 13, 2008

First night at King's Gap

Sunday night was opening night for the King's Gap banding. Since it is the southern-most banding site, King's Gap opens about a week later than the two other banding sites. It is about 30 and 40 miles further south than the Small Valley and Hidden Valley banding sites, respectively.

The net lanes were in need of some trimming and raking to keep leaves and sticks out of the nets and the four nets had to be set up. As we started up the audiolure, there was not a lot of optimism about our chances of catching an owl. It was an absolutely beautiful night, but the warm weather coupled with a full moon and no clouds were not ideal conditions for catching saw-whets.

We occupied ourselves between net checks by watching the flying squirrel that was scampering around the banding station and scaling the walls, looking for food. Anna and I also tried out the GPS (Global Positioning System) units we will be using for the telemetry project, making sure we know how to use them. These units have the ability to communicate position with each other so while we are in the middle of the woods we can easily see where the other two telemetry teams are, allowing us to better triangulate the owl we are tracking.

After some field-testing of the GPS units and hearing a Great Horned Owl hooting off in the valley, we headed back to the banding station to find out the banders had caught their first owl of the season. The bird was a second year (SY) female, which I believe is all we have banded so far this season at our three locations. This particular bird weighed in at 88 grams and had very little fat on it.
One final net check at midnight produced no more birds so we closed up for the night. The telemetry crew will be back at King's Gap tonight, hoping for another saw-whet owl. If we are lucky, we'll be putting a transmitter on a saw-whet early this week and begin tracking it as it travels around King's Gap.

Sunday, October 12, 2008

Picking up steam

The milder weather that has settled over the Northeast since mid-week hasn't been great for owl migration, but we're continuing to get one or two birds a night, mostly at our Hidden Valley station. (Small Valley was closed over the weekend while Girl Scouts were using the camp.)

Tonight all three sites will be running, as our third station, King's Gap in Cumberland County, starts up. Unfortunately, the mild southwesterly flow is going to continue for a couple more days, and the moon is rapidly waxing as well -- conditions that are less than ideal for fall migration, when we prefer to see a blustery cold front followed by nights of calm, cold and moonless skies.

But we're continuing to follow "Dizzy," the second-year female saw-whet we radio-tagged on Monday. Yesterday (Saturday, Oct. 11), I spent the day with research tech Anna Fasoli, looking for Dizzy in the Haldeman Tract of Weiser State Forest in northern Dauphin County.

When we met at Small Valley there was no whisper of a beep from the owl's radio transmitter, so we split up and each looped north along different routes into state forest, covering an area about six miles by three miles before reconnecting, driving slowly while listening through the white-noise static on our radio receivers and roof-mounted antennas for any hint of the signal.

Still nothing, so Anna suggested we drive out Wolf Pond Road, which dead-ends after about two miles at a steep escarpment where hang-gliders have a take-off ramp; it's a great overlook, she said, and might be a good spot to pick up a distant signal. But before we reached the hang-glider site, we both picked up Dizzy's signal, booming through the receivers -- she was holed up in a grove of white and pitch pines less than a hundred yards from the road.

Narrowing the search down to a yard-sized area was pretty easy; actually getting a look at Dizzy was not, and we spent nearly an hour shuffling back and forth, alternately waving our hand-held antennas and scanning the dense treetops with binoculars. The white pines were about 75 feet tall and very thick, and we could find no whitewash or pellets. And at that range, the signal was so loud it was hard to localize, even with the gain turned way down, so we tried an old telemetry trick -- jumping off frequency. Instead of setting the receiver to the correct frequency (say, .2850 MHz), we set it to .2950; this attenuates the signal considerably and allows one to take a more precise location. That got us down to one of two neighboring trees, so we jumped another hundred megahertz off the frequency, muting the signal so much that we could determine exactly which pine she was in.

And there she was -- by peering just so through a gap in the foliage, we could see her sitting about ten feet from the top of the tree, holding a deer mouse, on which she was actively feeding. Then it was merely a case of taking all the habitat data that we collect on both the roost site and a randomly selected site 20 meters away.

It's always a thrill to see one of our birds in the daytime, and Dizzy's been a good sport. Our hope is that when King's Gap opens, though, we'll be able to quickly tag an owl there, and shift the telemetry to our normal stomping grounds in Michaux State Forest, where access is a lot easier than we've experienced in the Weiser forest.

Here's a Google Earth image showing Dizzy's movements during the week; the Oct. 8 roost site is based on triangulation, and the colored block shows the rough area in which it may have been. (Lest anyone think we're jeopardizing her by giving out her location this way, consider how long it took us to find her with two radio receivers!)

Scott Weidensaul

Wednesday, October 8, 2008

Tracking Dizzy

With the high pressure cell settling in overhead, things slowed on the migration front Tuesday night, with no owls caught at either Small Valley or Hidden Valley, although the SV crew had a screech-owl close to the nets while they were closing up. (We often catch a few screechies each season that stumble into the nets, either by accident or because they were looking for a saw-whet for dinner.)

However, it was a very active day and night for the telemetry crew. Monday night after I left SV, Anna Fasoli and Drew Weber continued to track Dizzy, the owl we'd released earlier that evening, as she moved around Small Valley, the heavily wooded region where we band. They struggled with some areas where the topography produced odd signal bounce, but once it appeared Dizzy was settling in, they quit for the night around 1:30 a.m.

Late yesterday afternoon, Anna came back to try to find Dizzy's roost. She localized the signal fairly close to the cabin where we band, but neither she nor Drew, who joined her, could get a visual on the owl.

I'm not entirely surprised, because saw-whets can be maddeningly hard to spot - one reason they have long been assumed to be rare. Before leaf-fall, they generally roost high in the outer branches of hardwood trees, often an especially large tree that partially emerges from the surrounding canopy. What's more, they'll tuck themselves partway into a clump of leaves, so pesky flocks of chickadees and titmice don't spot them and raise a fuss. After the leaves drop, the saw-whets switch mostly to conifers, but finding a robin-sized owl in a pitch pine full of similarly sized cones is another challenge.

By about 7:45 p.m. EDT, Dizzy came off her roost. For the next two hours Anna and Drew were able to biangulate her position as she moved around, possibly hunting, but then the owl began to move more rapidly out of the area, and they soon lost her signal entirely. Despite a lot of hiking, followed by a lot of late-night driving on mountain roads through Weiser State Forest, they were unable to relocate her.

Anna will be going back to the banding site today in hopes that Dizzy returned to her previous roost -- or she may have decamped from the area entirely. This is the gamble we take every time we put a radio on a saw-whet; for every bird that sticks around for a couple of weeks, giving us lots of data, we get at least one that vamooses, taking our radio with it.

Scott Weidensaul

Tuesday, October 7, 2008

Off to the Races

After a slow start, things are finally hopping, and it's only going to get busier.

Sunday night we caught our first saw-whet of the season at Small Valley in Dauphin County, a second-year (SY) female which, in addition to a numbered leg band, also received the first radio transmitter of the season. The tiny, 2-gram device smaller than a pencil eraser is held in place in the middle of her back with a figure-eight harness of lightweight elastic beading cord.

The crew nicknamed the owl "Dizzy," because of the way she was spun up inside the mist net. After holding her overnight to make sure the harness wasn't interfering with her, we released her at Small Valley Monday night, and research technician Anna Fasoli, intern Drew Weber and I spent hours following her movements as she steadily shifted farther and farther east of the banding site.
Aura Stauffer, left, and Anna Fasoli fit a radio transmitter onto "Dizzy." (©Scott Weidensaul)

Smaller than a pencil eraser, the transmitter is all but hidden by the owl's back feathers. (©Scott Weidensaul)

This was mostly a shakedown for the intensive triangulation work we'll be doing this fall, using three tracking teams to simultaneously record bearings on the signal from the owl's transmitter, thus allowing us to plot its location through the night -- something that's rarely been attempted with saw-whets.

While we were tracking Dizzy, bander Guy Ubaghs and his SV crew caught two more saw-whets, including a "foreign recap," an owl banded elsewhere. When I find out where she was banded, I'll be sure to post it. Already this season, three of our owls from previous years have been reported, two in Ontario and one this weekend in western Massachusetts.

Over at our Hidden Valley site in Schuylkill County, bander Jim Logan Sr. and his crew had their first saw-whet of the season. Our third site, King's Gap, opens this weekend.

Driving to and from our sites at night is always a little dicey, given all the deer, but for the second time in little more than a week, I had to brake hard Monday evening on my way to Small Valley to avoid hitting a big black bear that loped across the road in front of me.

Scott Weidensaul

Sunday, October 5, 2008

Still waiting

The first week of our season is usually slow, and 2008 has been no exception. The only site operating Saturday was Hidden Valley (Small Valley was closed for banding because Girl Scouts were using the camp, and King's Gap won't open until Oct. 11), and bander George Gress reported "no coyotes, no owls, just another dose of 2006 quiet." For members of our crew, invocation of 2006 carries a special significance, since that was our worst season ever -- in the first 26 nights of fulltime banding, we caught only seven owls.

Fortunately, I don't think this is going to be another 2006, in part because of the reports from our north. Yesterday morning we got word that one of our 2007 owls has been reported -- an SY-F (second-year female) banded Nov. 2, 2007 at Hidden Valley, which was recaptured Friday night at Prince Edward Point Bird Observatory (PEPtBO), on the north shore of Lake Ontario.

Dave Okines, who runs PEPtBO, caught 68 NSWOs Friday, including eight foreign owls. He's up to 159 for the season, which started about two weeks ago for them...not huge numbers, but quite respectable. PEPtBO is on a long peninsula at the northeast corner of the lake, a terrific migrant funnel, and a lot of those owls will be coming this way, because we get more interstation recoveries of PEPtBO owls than from any other site.

Here's a map showing the locations of our three banding sites:

And here's where PEPtBO is in relation to us -- directly upstream, so to speak:

A lot of birds coming south out of Ontario hit the lake and split to either side, many going through PEPtBO, others down the Long Point peninsula on Lake Erie, opposite Presque Isle, PA. We get some of Long Point's birds, but not nearly as many, unsurprisingly.

Tonight Hidden Valley and Small Valley are both open, and I'll be at Small Valley with research tech Anna Fasoli, telemetry coordinator Aura Stauffer and intern Drew Weber, hoping to intercept our first saw-whet of the season and bestow a radio transmitter on it. For the past two weeks Anna has been running "error tests," trying out our triangulation techniques and mapping software using hidden transmitters in lieu of live owls, and we're ready for the real deal.

Friday, October 3, 2008

Open for business

We opened our Hidden Valley (western Schuylkill County) and Small Valley (northern Dauphin County) sites Wednesday night - our third site, King's Gap in southern Cumberland County, is a bit farther south than the other two, and the arrival of migrant owls there is always a bit later, so it's opening Oct. 10.

The weather was a little iffy -- lines of thunderstorms were moving across the state in advance of a major cold front, and I was so sure we were going to get wet partway through the evening that I suggested the two volunteers coming to help me at Hidden Valley, both of whom had to drive a long way, take the evening off, which they did.

It didn't rain, but neither did we catch any owls at either site. This is fairly typical; we open each year on Oct. 1 knowing that it's probably before the first migrants arrive in this area - that way, we're able to document the full extent of the fall movement of saw-whets.

And I enjoyed the rare evening alone in the woods. It was twilight as I opened the line of four 40-foot-long mist nets that are the heart of our operation, each one about eight feet high and almost invisible. I was just unfurling the last one when a coyote began to howl, just upslope on the mountain a few hundred yards -- a wonderfully weird song that is thrilling and hair-raisingly eerie at the same time. Then another joined it, before they both moved off down the ridge.

Then I started a little music of my own, flipping the switch on a digital MP3 player attached to two large bullhorn speakers. The woods were filled with the mechanical "toot, toot" of a male saw-whet owl, the audiolure that attracts the migrants to our nets.

I checked the nets every hour from then until midnight, but except for a meadow jumping mouse that pinballed off through the woods, and the snorts of a couple of deer, I didn't see or hear another animal all evening.

Thursday night was near-perfect. It had been a blustery, post-frontal passage day, with strong northerly winds which largely died off at dusk -- ideal migration conditions. But except for the call of an eastern screech-owl at Small Valley, the crews had no birds.

Even in major irruption years, like 2007, the first week can be slow. Eastern Canadian stations are just getting their peak flights now, and our peak doesn't come until the end of the month. This is a time for working out the kinks and preparing.

As always, we're grateful for the strong support of the Ned Smith Center for Nature and Art, which has sponsored this research since 1997. This year, we're also grateful for a significant gift by the Delaware Valley Ornithological Club, and a major grant from the RJM Foundation, which among other things is underwriting our greatly expanded radio-telemetry program -- more on that in a later post.