Do the same House Wrens nest in the same house every year?

We got one of those gourd wren houses years ago, hang it in the same spot at the eaves of the porch roof, clean it out of nest materials every fall, and wrens come back each spring. Are these the same adults, the offspring who were born in that nest or just random adult wrens?

Also, the gourd house came with an entry hole about an inch or more and a small stick under for a perch. This year we got another one, but this had no perch and as I could not see how any bird could get into, especially as the surface had an ultra smooth finish, I drilled it and added a dowel for a perch. The hole is only about 7/8 inch, but they seem to go in and out OK. ~ Averill Park, NY

The House Wren’s bubbly song and habit for eating masses of bugs make it a very popular bird at many homes. As a result the birds range and population in North America has grown with urban sprawl. Like the House Finch, they were named for their preference for nesting near peoples’ houses.

The average lifespan of a House Wren is about 7 years old, but that is difficult to verify because wrens don’t always return to the same area every year. House Wrens are seasonally monogamous. In the spring, the male and female partner and share the responsibilities in raising their young. But pairs often switch partners between the first and second brood during the season.

A male House Wren arrives first in the spring and begins to lay claim to a nesting cavity by filling it with more than 400 small twigs. When the female arrives, she’ll inspect the twig structure and then take over, adding the nest cup and lining it with grass, inner bark, hair, and feathers. Wrens will usually lay 2 broods in the nesting season from May to July.

Because the male Wren builds several starter nests for the female to choose from, the other nests may then be used by the male to raise a second brood with another female or remain in place to discourage other male wrens from nesting in the same territory.

Young wrens in their first year try to settle close to an established male and take their cues from more experienced males about what areas are good nesting sites.

House Wrens are famous for taking advantage of unusual nesting places. Nests have been found in mailboxes, flowerpots, boots, house lights, and of course old woodpecker holes, natural crevices, small birdhouses and gourds.

The hole size for House Wrens should be a minimum of 1” and a maximum of 1-1/4" to prevent sparrows from entering the house. Also experts advise people to avoid adding perches because wrens don't use them but predators can use them to gain access to the nest.

Sources:

1. All About Birds http://www.allaboutbirds.org/guide/House_Wren/lifehistory
2. Animal Diversity Web. -Dewey, T. and J. Brown. 2001. "Troglodytes aedon" http://animaldiversity.ummz.umich.edu/site/accounts/information/Troglodytes_aedon.html.