Wednesday, June 10, 2009

This day was for the birds, gladly

kw: observations, birds, wildlife

This is a house swallow sitting on a bluebird box, which is probably holding her eggs or babies. I belong to a volunteer program at work; a colleague and I make weekly checks of four bird boxes of the 25 or so that are scattered about the complex. The boxes are made with a hinged front so we can look inside. This is one of a number of projects that the company does under the aegis of the Wildlife Council.

When I joined the program two years ago, a number of us got a short session of training, and then we were assigned a few boxes per pair of us. Though these are called bluebird boxes, and bluebirds are the most desirable species we wish to encourage, there are three other species that we allow to use the boxes: house swallows and two species of wren.

We were told to specifically discourage invasive sparrows, which are not native to the U.S., by removing their nests and eggs. Fortunately, I have had to do this only once. It is a sad duty. Last year, I didn't have any bluebirds in any of the four boxes I (and my colleague) care for. Three pairs of swallows fledged from four to six young each, and one box was fought over by wrens and starlings, and nobody raised any young.

The hole on that last box was too big; starlings won't try to use a box with a bluebird-sized hole. We asked the facilities folks to make a front with a smaller hole. That worked. This year, that box has six pale brown wren eggs in it, and we saw one of the parents flitting about when we checked inside.

The swallows are running a couple weeks earlier than the wrens this year. We first saw white swallow eggs five weeks ago, six each in two boxes. Two weeks ago the eggs were still being sat upon. Last week we saw tiny baby birds. Today I took this picture in one of the boxes with babies. This youngster is just beginning to get big feathers on the wings (barely visible to the right), so it is about 10-12 days old.

We didn't open the other box of swallows; we could see the parents actively bringing food. We won't open either of these boxes until we don't observe any more feeding behavior. This year especially, things got started early enough that the swallows may raise a second brood. We hope to catch them re-lining the nest and laying a second clutch of eggs.

One of the boxes that had a successful family last year has so far produced nothing. At the beginning of the season we found a half-completed nest with a dead swallow inside. We cleaned it all out. Two weeks later a messy sparrow nest got built up, and when we saw eggs in it, and verified that they were being sat on by a sparrow, we removed nest and eggs. That was last week. This week there were a few straws in the box, but it doesn't look like the sparrows intend to finish the nest. Next week we'll know more.

So, this year so far, two boxes that started with six eggs each have several live babies that are about ten days old; one box has a clutch of five or six wren eggs; and one is probably not going to be used. Who'd have thought such drama goes on in these little boxes?

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