Tuesday, May 29, 2007

The Western Tanagers

We were fortunate to spot several western tanagers while camping this weekend. I didn't get a good photo of the breeding males so I stole a couple pictures from other websites for your viewing pleasure.
Here is another photo of a western tananger being held by a bird bander in a photographer's hold.

Let me explain:

Bird Banding is a process in which birds are captured and "banded" with a metal bracelet that contains a bird-specific identification number (see picture, above). If that bird is ever caught again or is found dead, a person can call in and give the band number to a national resource center. It may seem pretty trivial to call in one band number on one bird when there are millions upon millions of birds in the world. However, there is an amazing of amount of information regarding bird migration that is simply unknown to date. The information from one bird could be very important. When I was an intern for the BLM in Salem, we banded songbirds in a mountain meadow. My boss had birds that had returned to the same meadow each year for almost a decade. Can you imagine that? A tiny songbird leaves a meadow in Oregon and flies down to South America for the winter and then makes that arduous journey back up to Oregon, year after year. That is an amazing journey.

The most common method of capturing birds is with mist nets. These are nets made of very fine, black line. The key to setting mist nets in to place them in common flight paths. At Mike’s Meadow, we placed ours in the aspen and willow shrubbery around the perimeter of the meadow. The nets extends upwards approximately 10 feet off the ground. It’s important not to let the nets drag on the ground (in wet vegetation) since birds can get chilled quite easily and are easy targets for predators.

A bird typically becomes tangled in the pockets of the mist net. Here comes the tricky part: extraction. Taking a bird out of the net can be extremely difficult. I found that I dearly loved the challenge of untangling a stuck bird. Birds tend to have very distinct personalities in the net. Robins and chickadees are fighters. They’ll bite, squabble and raise a general ruckus. At times it even seemed like some were pros at “directional defecating”. Yuck! Wrens are notorious for “spinning” in the net and can make extraction very difficult. Hummingbirds are so small that they sail headfirst through the net and get stuck like fat sausages halfway through. They’ll hum indignantly at you too.
My favorite bird in the net will always be the spotted towhee, probably because it was the first bird I ever extracted. You can tell the one pictured below is an adult due to the red color in the eye (young birds will have an orange eye).
Once a bird has been safely extracted from the net, it is placed in a bag so the bander can collect the remaining birds in the net.

A bander will carefully removed the bird from the band and place the bird in a “banding” hold (below).

Hummingbirds require a different sort of holding technique. Most people typically don’t band hummingbirds since they require very small bands. Hummingbirds (and swifts) belong to the taxanomic order Apodiformes, meaning “unfooted birds”, consequently you can probably see why it’s so difficult to band them. The Seattle Audubon Society has a pretty well known hummingbird bander (who is also the husband of the UW rowing coach, Jan Harville. Rowing and birds, how cool is that?!).
Once the bander has the bird in hand, she bands the bird and then records information that is then passed on to the national database: sex, age, fat reserves, body and flight feather molt, wing length, and body weight. Occasionally we’ll pluck a tail feather for DNA studies.

Afterwards, most bird banders like to gloat over their catches (much like hunters) so they transfer the bird into the photographer's grip prior to taking a picture. I've done this on numerous occasions. Some people feel that the photographer’s grip makes the bird more susceptible to broken bones (which can be fatal for songbirds). In my limited experience, I've found this grip can be used fairly reliably with birds with hefty leg and foot bones.
After the picture is taken, the bird is released. Most will fly away immediately but sometime they’ll hang around for a second or two to get their bearings. Hummingbirds will sometimes cock their head at you as if to say “What? We’re done? I was just getting comfortable!” before buzzing off into the bushes. And if you're too worried about working with birds, you can always practice your photographer's hold with the other local fauna.

I took a couple of those pictures. The links to the remaining photos can be found here,
here, here, here, here, here, here.