How Many Times Do Bluebirds Lay Eggs? Clutches and Broods

Bluebirds can lay more than one clutch in a breeding season. An Eastern Bluebird may raise one to three broods; a clutch commonly contains four or five eggs. Western Bluebirds may also have one to three broods, while Mountain Bluebirds have one or two. The numbers vary by species and nest, so there is no single answer for every bluebird.

A clutch is the eggs laid for one nesting attempt. A brood is the young raised from a nest. Keeping those terms separate helps answer both meanings of “how many times”.

How many eggs are in one bluebird clutch?

Cornell NestWatch’s clutch-size guide gives typical counts of four to five for Eastern Bluebirds, four to six for Western Bluebirds, and five to six for Mountain Bluebirds. The wider ranges recorded in Cornell’s species accounts are:

• Eastern Bluebird: two to seven eggs in a clutch.

• Western Bluebird: two to eight eggs.

• Mountain Bluebird: four to eight eggs.

Those ranges describe individual clutches, not the number a female lays in a whole season. The eggs are usually pale blue, but Cornell notes that white eggs can occur in all three species. Colour alone does not tell you whether an egg is healthy.

How many broods can bluebirds have in a year?

Cornell lists one to three broods for Eastern and Western Bluebirds and one to two for Mountain Bluebirds. This describes the number of broods they may raise in a breeding season, not a promise that every egg hatches or that every pair follows the same schedule. If you are watching an Eastern Bluebird nest, a later clutch in the season can be normal.

Brood counts are not a firm limit on egg-laying attempts. If a clutch fails, a pair may lay a replacement clutch; Cornell NestWatch counts that as a new nesting attempt. The brood count therefore cannot tell you exactly how many times a particular female will lay eggs in a season.

Once chicks leave the nest, our bluebird fledging guide explains what happens next.

Does a female lay all her eggs on one day?

No. Cornell’s explanation of bird egg laying says songbirds generally lay one egg a day until the clutch is complete. A nest with only one or two eggs may therefore still be in the laying stage. Do not use an early count to predict the final clutch size.

“Virtually all songbirds lay one egg per day, usually in the early morning, until the clutch is complete.”

Should you check or move bluebird eggs?

Watch from a distance unless you are following an established nest-monitoring protocol. A short gap in seeing an adult is not proof that a nest has been abandoned. Do not take eggs indoors to candle them or decide a nest has failed from a brief observation.

This article covers Eastern, Western and Mountain Bluebirds in North America. Species, location and the result of each nest can change what you see in a particular breeding season.