Showing posts with label chickadees. Show all posts
Showing posts with label chickadees. Show all posts

Wednesday, May 22, 2013

Bluebird Report May 22 - First Eggs!

The contrasts between last year's early spring and this year's late one continue to be stark. By this date last year we'd had several sets of bluebirds fledge already, but we just found the first eggs of the season this week while checking the nest boxes we monitor weekly. As of Tuesday evening we had two nests with one egg each and this nest with three. Once they start laying, bluebirds lay one egg a day, with a typical clutch size being four or five eggs (most of ours last year had five). 

Three eggs - a beautiful sight!

There they are!


On our rural Rice County bluebird trail, which this year has eight sites (four single nest boxes and four pairs), we now seem to have four bluebird nests, two tree swallow nests (no eggs yet), and one black-capped chickadee nest.


Tree swallow nest full of feathers

Black-capped chickadee eggs in mossy nest

The chickadee nest, above and below, is at the location where our most successful bluebirds were last year. We also have chickadees nesting in one of the nestboxes at our house in Northfield. Last year we had a couple of chickadee nests started, but no eggs. Chickadees are cavity-nesters that will use bluebird boxes. They build their nests with soft moss, and as can be seen here, they obviously supplement with other found materials. This is a very soft, fuzzy nest for these six speckled eggs. Chickadees typically lay six to eight eggs (see the sialis.org page about chickadees).

Chickadee eggs

We hope to see these eggs hatch in another 11 to 14 days and the chickadee nestlings successfully fledge in about four weeks' time.

Follow our whole bluebird trail adventures here: Bluebird Trail.

Tuesday, May 7, 2013

Bluebird Trail - 2013 First Report

The horrendously late spring this year, including heavy snowfalls in late April and early May, has our bluebird season off to a worryingly slow start. It seems likely that there has been significant mortality for these insect-eating birds, since the insect season is also starting slowly due to the cold.

Tree swallows on overhead lines

By this time last year, we had 20 bluebird nestlings already! This year we have just started to get out to check the boxes, and we barely have any nests that are more than a few strands of grass, let alone having eggs or nestlings.

We have only seen two bluebirds yet this season, one male and one female, seen on different days at our prairie-habitat trail, where one of the four boxes today had a substantially complete bluebird nest. Tree swallows have been much more conspicuous on or near several of our other boxes. Perhaps tree swallows, which eat flying insects in the air, may have had an easier time finding food than bluebirds, which pick insects off the ground.

We have complete or nearly complete chickadee nests in two of our boxes, while last year we had no complete chickadee nests.

We plan to move some boxes from a couple of areas that last year produced wrens but no bluebirds.

Follow our whole bluebird trail adventures here: Bluebird Trail.

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.