The male house wren arrives in late April or early May from southerly wintering grounds to establish a spring nesting site. He will stake out a territory of up to one acre, threatening, chasing and even fighting intruders from his claim. While males wait for females to arrive, they become devoted nest-builders. An individual will build up to a half dozen nests to let birds in the area know there is no vacancy at that site. When the female arrives, she chooses just one nest and she will then completely rebuild the nest twig by twig.
Wrens have been known to nest almost anywhere. Nearly any hole a wren can get into is an appropriate place to build a flowerpot, a mailbox, a boot, an abandoned woodpecker hole, a basket, or even a pair of pants on the clothesline.
Wrens will also readily use a man-made house. The hole opening on a wren house should be between 1 and 11/4 inches. The wren, one of our smaller birds, will have no trouble getting in a hole this size but starlings, house sparrows and predators won’t be able to enter.
House wrens feed almost entirely on insects. They will also occasionally visit a feeder that offers suet, peanut butter, cornbread, and white bread crumbs.
Woodpeckers are primarily cavity nesters. Rather than move into a ready-made birdhouse, they prefer to excavate their own cavities by drumming their chisel-like beaks into softwood trees. The actual excavating is an important part of their instinctual life. There are some types of woodpeckers that may never accept a birdhouse, and often a woodpecker will excavate a new hole in the same tree as the previous year, rather than reuse an old hole.
When a woodpecker does use a birdhouse, he seems compelled to enlarge the birdhouse entrance before settling in. Sometimes this is done to make the hole entrance more comfortable; at other times it appears that the instinctual behavior to excavate needs to play itself out.
Some woodchips that result from excavation fall to the inside of a tree cavity or house and serve as a lining for the nest. Unlike other species, woodpeckers do not bring in any nesting material of their own. When putting out a house for woodpeckers, adding 1-2 inches of woodchips to the floor of the house will help keep the eggs warm and snug. We recommend that you locate the house in an area that includes dead trees and stumps, where woodpeckers find insects, their main food source.