The Nemesis Bird » Birds of N. America Online

Banding the Saw-whets

Drew — Mon, 15 Oct 2007 17:21:00 +0000

female Northern Saw-whet Owl

A few nights ago I had the opportunity to help band saw-whet owls at a Girl Scout camp close to Halifax, PA. This excited me because, although saw-whet owls are one of the commonest owls in Canada and the northern US, I have rarely seen them. These owls are tiny, with the males only weighing as much as an American Robin (~75 g) and females just a little more than that. Saw-whet owls are a common target for banding because they are migratory, arriving in PA between October and November.

We were looking forward to a busy night because a cold front had just passed thru and the wind was generally calm. Plus, we had heard reports from further north reporting some huge catches recently and were expecting a huge influx at any time.

a little male

Our first net check produced 2 owls, the very small male in the photo above, and the female that is squinting at you in the first photo. You can also see the leg sizing tool and banding pliers in the above picture.

qualifying eye color

There are a lot of unknowns as far as ageing saw-whet owls. To better determine different characteristics that might give clues to age, many banders take additional information such as eye color, amount of white in face and amount of barring on the alula. Above, the bander is comparing the shade of the owl’s eye to a paint strip.

wing from the squinting female above

By looking at the condition of the wing feathers, it is sometimes possible to tell how old the bird is. Without getting too technical, you can see that the outer five primaries (p6-p10) are darker than the inner five primaries (p1-p5) and the adjacent 5 secondaries (s1-s5). The inner secondaries are again darker like the outer primaries. The darker feathers are from one molt cycle and the light feathers are from the previous molt cycle. This would make the owl at least 2 years old.

underwing shot with blacklight

Another way to look at feather age is to shine a blacklight on the underside of the owl’s wing. The newer feathers have a pinkish wash to them that really stands out when under a blacklight.

something on the ceiling

Occasionally the owls would become fixated on something in the room as they were being banded. sometimes it would be a face but other times it was hard to say what exactly the owl was looking at. This was one of those cases.

perched on the tree

After spending time being banded under lights, the owls are set out on a specific tree to recover their night vision and preen their feathers back into alignment. Occasionally they will remain for quite some time. The above bird remained for about half an hour as we closed the nets due to rain. We came back and were able to take pictures using a red light and no flash. We didn’t end up with the large catch we were hoping for but the 3 owls we did get provided the banders with valuable information and me with cute pictures and something to blog about.

Northern Saw-whet Owls are breeders in the forests of s. Canada of n. United States that are being logged at an accelerating rate. Regenerating forests do not provide the dead snags that are necessary for nesting. Already hard to observe, a declining population could mean that they will become downright impossible to see. Saw-whets do use nest boxes so if you live in a region that supports nesting Saw-whets, consider putting up a nest box.

For more info on the banders work visit Scott Weidensaul’s research page. You can also support thier work by adopting an owl.

The Hungry Herring

Drew — Tue, 02 Jan 2007 04:05:00 +0000

While at Barnegat Light State Park in New Jersey late last year I was lucky enough to photograph a Herring Gull chopping down on a nice looking sea star. I normally associate sea stars with Florida or the West Coast because that is where I have seen the most and so I was surprised at first when I recognized the gull’s victim. Gulls are not picky eaters. In fact, Birds of North America (BNA) states that Herring Gulls are a “generalist predator on pelagic and intertidal marine invertebrates, fishes, insects, other seabirds, and adults, eggs, and young of congeners. Opportunistic scavenger on fish, carrion, human refuse.” BNA also says that they swallow small prey items whole while large prey items (gastropods, bivalves, sea urchins, crabs) are broken up and eaten or dropped on rocks to break them open.

This guy really juggled the sea star around trying to fit it down his throat. He seemed frustrated that no matter which way he turned the sea star, its legs were still sticking out and he could not get it down his throat. As I left, he managed to get the sea star further down his throat but still had no luck as far as actually swallowing it.

The Christmas Post

Drew — Tue, 26 Dec 2006 06:57:00 +0000

Now that Christmas is officially over I feel as if I should past what I got today. Highlights include a brand new eastern edition of Sibley’s, a tiny little camera case, an awesome Mountain Hardwear down vest, and some clothes. But the most exciting present of all was a year’s subscription to Birds of North America (BNA) Online from Cornell Lab of Ornithology from my parents. For all you users of Ebird, they are offering the year subscription for only $25 which is really a steal for all the info you are getting in return. There is a book version of the which runs a couple thousand dollars and about 18,000 pages. I think that is a little excessive for a home library. But with the online version you get all this info as well as updates, sounds and videos of the birds.