Murderous House wrens devour insects and drive away other birds

The House wrens have taken over my backyard, chasing out the chickadees and other cavity nesting songbirds. Two bird houses build for different species of birds, a welcome sign and a fake birdhouse have become nests for raising little wrenlets.

A couple of weeks ago while I was trying to take a nap in my backyard I was interrupted by some noisy baby birds calling for food. Hardly three feet away from my sleepy head I watched as a pair of house wrens made multiple trips in and out of the top hole in the “welcome” sign.

The pair must have thought the “welcome” meant for them, not for my guests that will brave my backyard.

The parents were very busy as they first delivered caterpillars by the dozen to their hungry kids. In a 30-minute period they delivered 22 creepy crawlers to the nest.

They also provided a diaper service for the growing family. After about every third food delivery, the adult would wait a couple of seconds and were given a white bag containing the kid’s soiled waste as they tried to kept their house semi clean.

Last week I noticed the soft food had been replaced by crunchier grasshoppers and beetles. Even a stinkbug was delivered and I wondered what that tasted like. But no, I will not try one. Two days after the food change the young were pushed out of the nest and took up residence is a pile of wood where they are being taught how to fend for themselves.

The female became a working single mom and it appeared that she was joined by another female with her brood as there were about 11 young with two adults living in the wood pile. Grasshoppers are being consumed by the dozens and since most of those insects cannot fly yet, the young wrens are fast learning self-sufficiency from the working moms.

Meanwhile back at the nest, the male had found a lovely female and after a few modifications to the nest she is rarely seen, while he spends a lot of time perching on top of the sign chimney. Occasionally he will bring in some morsel of food and disappear into the nest.

House wrens are notorious bullies, especially the males. The males start building several nests to allow a female to choose one and if another cavity nesting bird, like a chickadee has already started nesting, they will drive them out and destroy the nest.

They may even destroy other wren nests for their own use.

Now don’t feel too sorry for the abandoned female for after a week or two the stronger and smarter kids are on their own. The others have been eaten by wild cats or other predators and the female may move to the territory of another male to raise another brood.

I really don’t mind having these aggressive little buggers around as they live on bugs. I don’t have to feed them and they do not eat my berries, but they eat a lot of insects that are after my garden.

In fact, I may make a few more nests. I just hope they will leave my tree swallows alone as they are my mosquito control machines and I want them around.