Friday, April 6, 2012

Bluebird Trail, Week Two (Part 1) - Delight and Sorrow

This was a week of delight and sorrow on our bluebird trail.

First two bluebird eggs on our trail!

This is actually just part one of our Week Two report; we haven't been back out to all the nest boxes on our trail since last weekend, so I will follow this post with another in a couple of days, when we have a full report. But there is much to tell of our experiences with two of our nest boxes this week.

First, the delight. We were advised to check more frequently on the two boxes where a pair of bluebirds had built two nests (see #9 and 10 from last week's report), so on Wednesday evening my son and I went out there and found two beautiful blue eggs in the nest that had been started and completed first. We went back on Thursday and found a third egg, and still no eggs in the second nest box, which was good. Because of what we learned earlier on Wednesday about house sparrows, as described below, on Thursday we put up a sparrow spooker -- a short pole or more elaborate contraption with streamers fluttering from it and dangling on the roof of the box -- on top of the occupied nest box. There's evidence that house sparrows don't like those and will avoid them, but bluebirds don't seem to mind them much.

Same nest, next day - a third egg!

Now for the sorrow. This part is rather disturbing, and if you're squeamish you may want to stop reading now.

In the nest box where I'd noted last week that we thought we had a chickadee starting a nest (#2), we found our first evidence of what a house sparrow will do to other nesting birds. On Wednesday we saw a house sparrow on top of the nest box in the late afternoon and went to check it out. We discovered inside a poor chickadee that had been pecked to death, its head so badly injured it could hardly be seen (see photo below -- or if you don't want to see the photo below, you can click away to something else now). This is very typical of how house sparrows kill, I've learned, though it's less usual for them to go after an adult bird that does not yet have an active nest.

This very distressing discovery led to phone calls to our area bluebird coordinators, and Carroll Johnson came and brought us a Gilbertson trap, which blocks the exit hole of a nest box when a bird triggers it inside the box and keeps the bird inside until it can be released (which it must be, if a native bird) or euthanized (if a house sparrow). It's essential to get that house sparrow if we can and do away with it (humanely).

I am among the least violent of people. I would never kill an animal for sport (for food, if I had to, yes I suppose I would, but I would prefer to become even closer to being completely vegetarian than I already am if that choice presented itself). I don't even like to squish bugs, with the exception of mosquitoes or ticks that are going after me or mine. I rescue occasional small spiders from the bathtub before taking a shower so they won't drown. I did the same with a stray boxelder bug I found a few days ago. I would never have thought that I could do away with a bird -- until Wednesday. But I discovered through a little research that there's a saying among bluebirders: killing house sparrows is the second hardest thing bluebirders do. The hardest is finding bluebirds or their eggs or young in your nest boxes, destroyed by a house sparrow. Make that true for chickadees, as well.

Chickadee killed by house sparrow in nest box
So far we have had no luck catching the house sparrow. The trap was triggered once, but it was another chickadee and Dave released it. We hope soon to have materials to make the access hole smaller when we know we have chickadees nesting, so house sparrows can't get in. When you first put up boxes and are trying to attract bluebirds, you need to leave the hole bigger to accommodate the bluebirds you hope will start to use your nest box. And the size that will admit a bluebird is the same size that will admit a house sparrow, so that's a tough thing to deal with except by not putting up boxes where there are known to be house sparrows or in habitat that particularly attracts them. We have had occasional house sparrows here, but not very often. And we will certainly not feed millet or cracked corn, which are attractive to house sparrows, in the future as we sometimes have in the past. The millet is also attractive to some of our other favorite birds, like the white-throated and white-crowned sparrows that pass through here in the spring and fall, so it will be hard for us not to put out their favored food, but we won't. Note here a request: if you feed birds, please give careful consideration to not using the cheap birdseed mixes that contain a lot of the small, round millet seed, because by doing so you may well be inadvertently encouraging birds that kill other songbirds.

Here is a mini-documentary on the house sparrow, brought to my attention via Facebook from the blog Woolwine House Bluebird Trail:

I was feeling terrible on Wednesday (except for the almost simultaneous delight over the eggs in the other nest box), thinking that if we had not put up these nest boxes, that chickadee would still be alive. Then I realized that didn't really make sense. These birds are trying to nest -- they're not just nesting because we put up boxes. If they did not choose our nest box, the same thing could very well have happened in a nearby tree cavity, and probably does happen all the time. This is one of the reasons bluebirds, in particular, became scarce in the first place -- the double whammy not only of loss of habitat but also ruthless competition from these aggressive, non-native birds.

I've never particularly liked house sparrows, but I didn't particularly dislike them -- until now. I'll never look at a house sparrow the same again. I know they're just doing what comes naturally. But I don't want them doing it here.

1 comment:

troutbirder said...

Ouch! Interesting the ways of nature. Still aliens whether plants or birds can cause havoc when not in their own place...