Atop Hawk Mountain, Pa., 2010

Atop Hawk Mountain, Pa., 2010
Photo by R.E. Berg-Andersson

Sunday, June 26, 2011

It's a brood!

It has taken several weeks but there is now a noisy brood of baby house wrens in this box.

I first realized the skittish adults had settled down earlier this week when I saw a squirrel jumping out of the apple tree where the box hangs, apple in mouth, chased by a scolding wren. The wren even pecked at the squirrel as it ran up an oak tree, no doubt to its own nest.

(This will happen alot, unfortunately. Last year I was lucky to get enough apples to make three pints of apple sauce.)

Yesterday, early, I was outside and heard soft cheeps from the box. But when an adult showed up the cheeping became more insistent.

Since then the parents have been shuttling back and forth to a loud chorus of "Feed Me!!" in wren talk. Papa wren has been too busy to do much territorial singing. Mama wren has been quick to fly to a branch near me and scold if I get too close, or even if I come out the back door to dump some compost in my corner pile.

The other day I read a post on the NJ bird list from a guy in Basking Ridge whose first reaction upon seeing a bear in his yard was to get a camera. The bear had bent over the post holding his wren house, poured out the babies and ate them.

The guy's reaction? Too bad about the wrens but here are my amazing pictures.

Basking Ridge is not far from Morris Plains as the crow flies, although it is a fair piece of walking for a 200-pound bear. Had it been me and MH had been awake I'd have yelled at him to call the cops while I grabbed two pots to make noise running at the bear to scare it off. I know, I'm stupid. (I've done something similar to chase off a buck although when it put its head down to charge me I quickly backed off.)

My feeling is, if you go to the trouble to set up a habitat to protect birds and help continue the species, you protect them as much as possible. In my yard I chase off stray cats and have been known to wave a broom at cooper's hawks to keep them from the feeders. MH says even hawks have to eat and I agree but I say, let them eat elsewhere (or at least pick off the chipmunks).

It will be another week or so before the wrenlets start venturing beyond the box. Last year one fell from the box and was immediately snatched up by a jay before I could get out the porch door. Two others survived and I hope the two or three in the box this year do, too.

When autumn comes and I take down the box and clear it I will marvel that in this tiny space an adult wren was able to build a nest, lay her eggs and then feed the growing young. It's the same feeling MH gets when he thinks about growing up in a house with two parents and two brothers and only one bathroom - how did we do it?

You did it because you had to. It's why the wrens use the box and why I put the box up in the first place, my small bit to make the world a better place.

Sunday, June 12, 2011

Love is Blind

I do not like cowbirds.

They are ugly birds. The male is black with a brown head that looks all black in dim light. The female looks like an oversized, gray house sparrow.

I do not like the female because she also has an ugly habit of dropping eggs in the nests of other birds. This is known as parasitizing.

The cowbird isn't the only bird to do this. Some cuckoos drop eggs into the nests of other cuckoos, for instance.

But parasitizing is the only way the cowbird can continue the species. Cowbirds don't build nests. Nor do they kick out other birds to take the nests, as owls do. It is not known why they must use the nests of songbirds.

That is why at this time of year, when I am hearing the first broods of chipping sparrows, starlings, robins and titmice making a ruckus as they chase their parents begging to be fed, I expect my annual sighting of some pair of adult birds being harried by a particularly large, aggressively hungry chick.

One year I was walking to the train and saw a pair of carolina wrens feverishly trying to fill the mouth of a cowbird chick that was double their size. Cardinal nests are also prone to parasitization and, like the sun rising in the east, I will soon hear the very loud screeching of the cowbird chick in my bushes following an adult cardinal that is desperately looking for something to feed it.

You would think the wren, for instance, would recognize the intruder in its midst. Some types of bird do. The yellow warbler will build an entirely new nest over an existing nest if it spies the larger cowbird egg, neglecting its own eggs in the process of starting over.

But most birds, like the carolina wren and the cardinal, are not programmed that way. If there is an egg, the adult sits on it. And if that slightly larger egg hatches first, as cowbird eggs do, and the chick manages to push some or all of the other eggs or hatchlings out of the nest in order to hog the food, it isn't noticed by the parents. In their minds, they are raising the next generation.

But it's the wrong generation.

In Michigan, where the population of Bachman's warbler was practically wiped out thanks to a nasty combination of habitat destruction and parasitization, it is policy to catch and kill cowbirds within the designated Bachman warbler jack-pine habitat.

It may seem cruel but that has helped the Bachman's population slowly re-grow.

This isn't a problem for the cowbird. This is one bird where the destruction of its usual habitat has helped it.

Cowbirds were farm birds, picking bugs off the cows and the fields. But with "progress" has come suburban developments built on farm fields. There may be fewer farms but the cowbirds adapted and thrived. Too well, in fact.

One thing that amazes me is that after being raised by a pair of cardinals, for example, the cowbird chick will grow up and somehow intuitively know it is not a cardinal. Then it will find other cowbirds and at the correct, programmed time mate and start the parasitation process all over again.

To me this makes the cowbird, literally and figuratively, the dark side of nature.

Sunday, June 5, 2011

The Wren Days of Summer

There comes a time when you have to acknowledge spring migration is over.

No more blackpoll warbler, whose squeaky-brake call was heard for two weeks in the backyard. No more large flocks of goldfinches jockeying for position at the thistle feeder.

Far fewer birds are singing at dawn. The other day as I was hiking in the neighborhood I heard a strange song, then spotted a goldfinch. He wasn't singing but the male indigo bunting at the top of the spruce was.

But that's the exception. At this time of year birders leave the woods and head to the shore to look at the peeps and waders. The birds sit in the open and, if you can put up with the biting flies and mosquitoes, you don't have to work as hard at seeing something.

This is the season of the breeders. In my brother-in-law's New Hampshire woods, the black-throated green and blackburnian warblers still call to protect their nesting territory, the wood thrush and veery sing all day and the yellow-bellied sapsucker drums loudly on branches.

In my area, we have cardinals, catbirds, chipping and song sparrows and loads of robins. The chickadees, titmice and nuthatches sing every so often but they are more concerned with feeding young behind the thick tree canopy. If I didn't have suet out I might not be seeing downy, hairy or redbelly woodpecker.

Thankfully, there are wrens.

The carolina wren, such as this one from last winter, has a very loud song for such a little bird. If fed during the worst of winter, it will hang around all year. In the last week I have heard a carolina wren singing from the next street. One of the reasons why I love carolina wren is it sings all the time - in winter's cold, in summer, in breeding season. So this one is singing and is likely proclaiming his territory.

The other breeding wren is the house wren, which comes up in spring after wintering far to the south. (This year's current singer is at the top.) Years ago a friend gave me a small decorative bird house and for the hell of it I hung it in one of my apple trees. To my delight a house wren and mate raised a family in it. It was not meant to be a real birdhouse so it was not a surprise that it broke apart after a few years.

At that point I went to the local Audubon office and bought this wren house.

I wait for "house wren" to show up on area birding lists and then put the house up. Usually within a few days there is activity and later a brood or two. (The opening is too small for the carolina wren.)

This year, as with everything else during a cold and wet spring, things were different. It seemed to take a long time for a house wren to discover the box and then after a few days it was silent. A week would go by and then there would be early morning wren song.

If you look at the house above you'll see a bit of stuff coming out the bottom - nesting material. I see a pair of wrens going in and out of the box but I don't hear any cheeping. At this point I am just glad to have them at all. It is nice to be awakened by a house wren's bubbly song rather than the alarm clock. It is nicer to hear the house wren nearby and the carolina wren a block or so away.

As I get ready to take the feeders in for the season the wrens will be my summer solace.