The same pair of Eastern bluebirds that already successfully fledged two broods from the nest box on our porch are going for another try, building their third nest in the porch rafters. The female makes dozens of trips each day, bringing leaves and pine needles, while the male keeps guard over the female and the nest building.
Yesterday I watched a house wren checking out the bluebirds’ latest nest. House wrens are known for destroying the nests of other birds to eliminate the competition for food. Sure enough, while watering the flowers this morning, I saw a pile of pine needles littering the ground below the nest. Undeterred, the female is rebuilding and if the house-wrecking wren doesn’t return, the nest will be completed soon and she will lay eggs.
Amazingly, Eastern bluebirds can have up to four broods (also called clutches) per year. There are many factors that influence the number of broods each year, including the availability of a mate, location, food supply, diet, health, age, and experience.
Both birds bring food to the nestlings and as the chicks grow older, the more trips required each day to keep them fed. By the time the nestlings are ready to fledge, both parents are busy all day long fetching the high-protein insects that make up their diet. It’s a very demanding and exhausting job!