Atop Hawk Mountain, Pa., 2010

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

Saturday, May 21, 2016

Another Year, Another House Wren

Welcome back, troglodytes aedon.

Every spring there comes a time when I either read a report of returning house wrens or hear one in an area not far from where I live. That afternoon or the next day I get out the wren box I've written about many times before and hang it from the same carefully selected branch in the apple tree, so chosen so I can see the box opening while the leaves keep the box shaded from the late afternoon sun. (Several past posts on house wrens were written in June 2011, and you'll have to go back to find them rather than click on a link. Apologies.)

Wren box (Margo D. Beller)
Usually it takes a week to 10 days for a house wren to find the box. This year was no exception, although it took the wren a day or two of scoping out the yard first - it went to the seed feeder, although house wrens don't usually go to feeders, and the water utensils, then flew back to the bushes.

I know when the box has been chosen because this is when this tiny bird proclaims its territory loud and continuously with its bubbly song. I have seen it high in a tree or in a branch above my head that allows it to face the box. Once you learn its song, you don't forget it.

Also, I know when he has found a mate. The song is the same but it becomes softer, more like a reassuring "I'm here, I'm just nearby looking for food." One of its song takes on a rising pattern, almost like a warbler. And there is that harsh scolding noise it makes if I or anything else come too close to the nest box.

It is not long before the female, if she agrees this is the right spot for the young, places twigs in the box. Every year I look for the tell-tale bit of twig coming out of the bottom of the box, a sign that this place is in use so stay away. Considering five to eight eggs are laid, I am continually amazed a nest and brooding female can fit. When the eggs hatch, both parents take turns getting food and sitting on the nest.

As the chicks grow, the parents stay outside the nest box but in close proximity. One parent flies to the opening with an insect and the peeping begins. It only gets louder as the young birds get bigger.

It takes about two weeks for these eggs to hatch and another two weeks before the birds learn to fly and leave the nest. At that point the box goes silent but I hear the brood following one parent or another around the hedges at the edge of my yard.

House wren, back yard apple tree (Margo D. Beller)
I learn new things about house wrens every year. The rising song I mentioned before was new to me this year. In past years I've learned a house wren has no hesitation in destroying the nest of another bird to take over the spot, in that particular case a black-capped chickadee that got to the box first. I have also learned jays will eat house wren chicks if one has the misfortune to get too close to the opening at the wrong time, or falls out to the ground when attempting to fledge.

Most times, only one wren family uses the box each year. That may be because when the apples start growing the squirrels start climbing everywhere and I start picking or, if out of reach, batting at the apples to bring them down with an extension pole. At that point the house wren may decide this is not his neighborhood.

But once in a long while, when apple season is done, another house wren comes by and checks out the establishment. It may remove some of the twigs or it may just use what's there, like renting a furnished flat.

House wrens got their common name because they will build a nest in anything - a flower pot, the pocket of a shirt on a hook, a tiny space inside or next to your shed. As long as it provides shelter from bad weather and is hidden from predators, it can be used.

(The larger Carolina wren, which stays in my area all year, will also build nests in anything and will sing loud and long to proclaim territory, draw a mate and warn if danger is near, even if it is only me. But it is too big for my nest box. The tiny winter wren prefers a different type of habitat than what my yard can provide.)

My wren house offers a distinct advantage by its very wooden sturdiness and its hanging from a tensile wire strung from a branch. I've had to make some repairs to it over the years, but the pleasure my yearly tenants bring me is more than worth the effort. Then, when the house wrens head south for the winter, the box is cleaned and brought inside to await another year and another house wren.