The Bufflehead Birder

February 17, 2009

Last Owl in is a Winner

What weighs 88.4 grams and comes in a drawstring bag?

Weigh In

Here’s another bunch of clues. It has yellow eyes, a 10.3 mm bill length, and sometimes you can find it in a mist net at night. Sometimes it can be adopted.

Exactly. 

A Northern Saw-whet Owl.

If you read my post “Waiting for Godot’s Owls” you will recall the long evening I and other Delaware Valley Ornithology Club members spent anticipating the capture of a saw-whet or two, but that ended without a single owl appearance.

But, apparently, waiting around for owls can be addicting. After 5-6 hours hanging out with DVOC members on that first outing to the Hidden Valley banding station I was chilled, drowsy and ready for bed, but begging to come back the next week to sit and wait for those elusive owls.   

The 2008 season was a low one for Saw-whet Owl captures along the Kittatiny Range. Barely over 200 individuals had been caught between the 3 banding stations; Hidden Valley, King’s Gap, and Small’s Valley.  Compare that to the 900 owls that might be banded in good years.

When there had been zero capture during my second visit to Hidden Valley I had begun to accept that this was not going to be an owl-year for me. However, I figured that, owl or no owl, my third and last visit would still offer one more pleasant evening of conversation with the project volunteers on duty and another chance just to savor that essence of being in a forest at night. 

I stepped from my car, greeted by the audiolure’s call of a male Saw-whet Owl that echoed through the darkness, and the crack of yellow light that spilled from the cabin door as Nate (bander and researcher) welcomed me inside for another owl vigil.

We sat with our feet next to the heater under the banding table, and within a comfortable reach there was a plentiful offering of snacks, including hotdogs and saurkraut. The evening was as mellow as previous ones until the door opened and an outstretched arm thrust a drawstring bag into the room.

the-gift.jpg

It was Nate’s arm. He had just come back from checking the mist nets but apparently was just standing outside holding this owl-bag through the door like it was supposed to signify something. Maybe the hotdogs and saurkraut had put up roadblocks along the neuron pathways in my brain because the understanding of what the drawstring bag meant did not take the most direct route from one neuron to the next. But when it finally got to the target neuron, I felt a joyful surprise as if someone had handed me a gift and I’d forgotten it was my birthday.

An owl had arrived. The first and only owl of the night, and a winner. The last owl of the 2008 season, bringing the total number of saw-whet owls banded by all three stations to 219.

And it was my owl in another way, too. On my first visit to Hidden Valley I got the adopt-an-owl bug and had signed up to be a proud parent of a saw-whet owl. The fee for the adoption goes to help fund the Northern Saw-whet Owl Project, which is sponsored by the Ned Smith Center for Nature and the Art. In return I get a certificate with a photo of me and my owl. Moreover, I will be notified of any future sightings or captures of my owl along with any accompanying data; was she seen as far north as Ontario? Was she eating an insect, a vole, a warbler? Did she have a nest with young? Did she look healthy?  

Owl Number 0924-17522

Owl adoptions also make great Xmas or birthday gifts, should you be considering something for a friend of relative. My sister-in-law and a couple of my friends will confirm this. Click here to get started on that gift list now.

Often the adoptive parent will be assigned an owl from any of the 3 banding stations maintained by Scott Weidensaul, but if you should happen to be present during the capture of an owl, you may request that owl as yours.

Cute to the extreme, a true pocket pet, this owl was a bonafide Precious Planet Critter if ever there was one. The owl was a ’she’, and I gave her the name of Chipeta.

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There was a lot of personal data to be gathered before Chipeta was to be released back into the woods. Nate took measurements of her tail and bill, and recorded the length of her wing when flat, as well as that of her folded wing (wing chord). He noted the thickness of adipose tissue on her body and whether or not her crop had remains of a meal in it. 

Essentials for Banding

Some necessities for banding saw-whets.

The wing chord length and the weight are the two determining factors that establish a saw-whet’s sex when there isn’t enough weight discrepancy between the males (75 grams) and the females (100 grams). 

Weighing slightly more than a shot glass full of vodka, Chipeta’s 88.4 grams was on the light side for a female, and it fell into the overlap of male/female weights. Therefore, both her wing chord length and her weight were correlated onto a Sex Ratio Chart and that told us she could be Chipeta and not Chip.

Taking Wing Cord Length   

Measuring the wing chord length.                    

Owls are the only birds that have the pigment porphyrin in their wing feathers. Porphyrin decreases as owls get older and it shows up well under flourescent light. The varying amounts of porphyrin seen in under a UV lamp help researchers read the molt pattern in the wing feathers and thus, estimate an owl’s age. For an excellent shot of what the molt patterns look like under flourescent light click here.

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Chipeta was found to be in her second year.

There are some physical traits, such as eye color, that vary among the saw-whet owls. Presently, no one knows what significance these characterstics may have but they are included in the overall data gathering. Eye color in saw-whets has come in the four shades of yellow seen on the eye color chart below. Chipeta’s eye color best matched the soft moonlight yellow (number 4) at the bottom of the chart. 

Eye Color Assessment

We also noted down the white on the tip of her beak.

And of course, most importantly Chipeta is fitted for her band.

Band Size

Chipeta takes a size 4 band.

Saw-whet owls tend to be calm while being handled and Chipeta was no different. During the whole exam and banding session she remained collected and stared back at us with as much curiosity as we did at her. But all too soon it was time for her to go, and hard as it was to resist slipping her “accidentally” into my coat pocket, our little friend was placed gently back into her drawstring bag. The bag was left suspended in an adjacent dark room so that her eyes could re-adjust to the darkness. Then after some 25 minutes Chipeta was released outside where she flew back into the dark and onto the rest of her life.

It is possible that I may never hear any news of Chipeta down the road, but as more and more owls are recovered over the years as the Northen  Saw-whet Owl Project continues, the odds increase in my favor. My biggest hope is to hear some news in another 7 years or so, when Chipeta will be a ripe age of 9 and has lived a full life in saw-whet years.

Pre-release

They say that good things come in small drawstring bags. Well, it’s true.

If you are interested in booking a visit to any of the banding stations please click here.

Should you ever find a banded bird, please call 1-800-327-BAND.

November 20, 2008

Waiting for Godot’s Owls

November 8th - Saturday Night

We were waiting for owls. So far none had shown up. But it was only 2 hours after dusk and we were to give it 4 hours because that’s when the owls really get active. That’s what research biologists Nate and Denise told us. So we sat back and opened a couple of more beers and passed the home-made brownies around again. I was with about 15 other members of The Delaware Valley Ornithology Club (DVOC) up in Hidden Valley on one of the highlight field outings of the year—spending the evening with researchers on the Northern Saw-whet Owl Project. The Saw-whet Project is headed by Scott Weidansaul, an author and researcher who works with migratory birds. I wish I could say that the owl photos below were mine but in fact, all the images in this post (including the puzzle afterwards) were taken by Philadelphia bird photographer Jamie Stewart, who was kind enough to let me use them.

SawWhetOwlBanding-1 by jaste1.

 Don’t you just love that face?

The Hidden Valley banding station is one of 3 located along the Pennsylvania Appalachians. The ridge alignment of these mountains, in particular Kittatinny Ridge, creates a corridor of favorable updrafts that comprise part of Atlantic Flyway. Nate was hoping for a low pressure system followed by a cold front because that would give the owls some umph to move south and improve the chance of a good capture rate that night.

From early October to the end of November many Saw-whets move south from Ontario and Northern New England. In winter months these owls may end up as far south as the Carolinas.

SawWhetOwlBanding-4 by jaste1.

The banding station cabin was unheated and there were port-a-potties located conveniently just outside. It was a nice rustic change for me from the Philadelphia suburbs. In a corner of the room was the banding table with a heat lamp, banding equipment, and then a short clothes line set up between two chairs with clothes pins. Nate said that some nights when there is a surplus of owls caught in a the net at the same time the researchers put them in sacks, which keep the little guys gently contained and calm. The sacks are then suspended from the clothes line as they await their turn at the banding table.

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This is one of my shots. It’s the only one on this post without an owl in it.

The body of a saw-whet owl is the size of a baseball and the head with feathers is not much bigger than a tennis ball. Take the feathers away, and the saw-whet skull barely weighs more than a ping-pong ball. Saw-whets are the smallest owl on the East Coast. Males, in general, weigh 75 grams while the females get up to a whopping 100 grams. Wee, fluffy, and unbelievably cute and cuddle-liscious, these owls attract dozens of banding volunteers who devote 2-3 evenings per week for 2 months on the project, as well as groups of visitors who want to see and learn something about these enchanting little owls.

SawWhetOwlBanding-7 by jaste1.

Every 40 minutes or so Nate and Denise headed out to check the mist nets again hoping to get that haul of owls they had promised us. The weather was good, the audiolure was playing the sweet and, well…, alluring call of a male Saw-whet to stir the females to get out and about and hopefully into one of the nets. About 80% of the saw-whets that are caught throughout the state tend to be females. So far there is no completely satisfactory answer for that. The best theory is that the males with territories may hunker down to defend them as long as possible while females are freer to travel. Another thought is that perhaps the high capture rate of females reflects the actual demographics of Saw-whet owl populations.

In 15 minutes Nate and Denise return. Too soon. Not a good sign. We jeered as Nate assured us that the 3rd and 2nd to last net checks usually had the best results, and then we handed him and Denise more brownies.

To keep us from pounding the tables, chanting, “We want owls!”, Nate entertained us with more notes of interest about these birds. First of all, there are a lot more of them in PA than was previously thought, especially during migration. They are generally secretive and not as easy to spot as larger and more vocal owls, like the Great Horned or Barred. They are less active on nights with a full moon as their feared predators, Great Horned owls can spot them easier.

In fact, one banding stations had to be closed down as a result of predation. In the same way Coopers and Sharp-shinneds learn that backyard feeders are easy pickings, so Barred owls in that area discovered that this saw-whet banding station was a prime food spot.  Silent and lethal, the Barred owls would follow behind the banders and snag the newly released saw-whets.  “Sneaky” was how Nate described them.

Later in the evening we were joined by Scott Weidansaul and several board members of the Hawk Mountain Sanctuary, and it got livelier and warmer with the extra bodies in the cabin. Scott made his rounds greeting us in his friendly and engaging manner.

“Isn’t banding exciting?” He asked one little girl, the youngest member of the group, who had shown absolutely no signs of getting tired as the night went on. “You get to see all this wildlife.”

Everyone laughed because it’s true both ways; as this night attested, you don’t always get to see something, but on the otherhand, sometimes you will experience more than you could ever imagine. Owl or no owl, the being there is good, and whenever I do finally see a Saw-whet it will be that much better appreciated for it’s not having been so available.

SawWhetOwlBanding-6 by jaste1.

Okay. One last net check. It was 11pm and almost time to call it a night and head home. Nate and Denise don their jackets and headlamps and head out again to check the nets. But soon they are back, empty-handed. Guess the owls had better things to do than fly into mist nets.  

So. No owls showed up that night. But I got to hang out in a cabin in the woods with other people who love birds, and be a part of something good. 

And then, there was an excellent bird joke told by our youngest member of the group:

Why don’t seagulls live by the bay?

Because then they would be bagels.

 

Waiting for Godot*

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