I don't think the baby birds will have any trouble. The migration south isn't as hurried as the migration north. There are still a lot of food sources available and plenty of time to mature. A busy forager in low tree branches and shrubs, the House Wren eats a wide variety of bugs. At the feeders they prefer mealworms, suet and nuts. House Wrens usually leave mid-Michigan by October.
House Wren Troglodytes aedon
Order: PASSERIFORMES Family: Wrens (Troglodytidae)
Description: Sexes look similar. House Wrens are a brown bird, darker above than below, with wings and tail dotted or lightly barred black. It also often flicks its tail up as it sings.
General: House Wrens are frequent visitors to mid-Michigan backyards and gardens and are famous for taking advantage of unusual nesting places. Nests from this prolific songster have been found in mailboxes, flowerpots, boots, house lights, and of course old woodpecker holes, natural crevices, and small birdhouses.
Their nest is a messy collection of twigs and sticks. Several nests may be started by the male to deter other birds from nesting in the area and allow the female to choose the best nest. After the female selects her preferred site she lines the nest with finer material including bark, grass, feathers and hair.
The House Wren lays 5-8 white, pink-white, or grayish, speckled or blotched with reddish brown eggs which she incubates for two weeks. The young are tended by both parents until they leave the nest two weeks later. Usually two broods are produced. Older adult males sometimes tolerate a first year male within their territory while it learns the ropes of what is a suitable nesting territory.
After the nesting season, the pair breaks up and House Wrens migrate to the southern United States and Mexico for the winter. Males return to the same breeding territory year after year. There is no information on site fidelity in females.
A group of wrens has many collective nouns, including a "chime", "flight", "flock", and "herd" of wrens.