Ask SIB: Will fledged wrens stay around?

Question: I have wrens that have nested inside my house I’m currently building. When the baby’s learn to fly will they fly around for a while or will they just go. Also if one is left behind can I continue to feed it?

– Alivia

Answer: Great questions! As a general rule, when a baby bird fledges it moves or is moved quickly away from the area of the nest. According to Birds of the World, the average time when a Carolina Wren comes off its nest to when it leaves its natal area is 27 days. A banded Carolina Wren was found 350 meters from its nesting area at the age of 79 days. This would imply that the birds in your yard move out into the neighborhood away from your yard. It may not be far, but enough that you will lose track of them.

Several hypothesizes could explain this tendency. Since the parent makes numerous trips to the nest area, it may be exposed to predators. The baby bird’s very vocal begging for food also enhances the danger of predation. Once a baby can fly, there may be a survival advantage from leaving the area. The other possibility for this rapid movement from the nesting area may have to do with food. It takes a lot of food to feed the hungry young and the parents do not want to travel too far. Over time they may deplete the food supply in the immediate area.

For many bird species. after the baby birds become independent and definitely before the parents start to raise the next brood, the parents drive heir progeny away from the nesting area or the young instinctively leave. Once again, a location can only support so many birds, so there may not be enough food naturally to feed birds from several generation. I liken it to getting our children to leave our houses when they become adults.

There are exceptions to this trend, but not with Carolina nor House Wrens.

Hope this helps!

– Bob Mercer, SIB’s “Resident Naturalist”