Eastern Bluebird

Overview

The eastern bluebird (Sialia sialis) is a small, migratory thrush native to North America, characterised by its bright blue plumage. As the state bird of both Missouri and New York, it is a favoured subject among birdwatchers and is currently classified as Least Concern on the IUCN Red List.

Identification

• Size and Build: Small birds measuring 16–21 cm in length with a wingspan of 25–32 cm and a weight of 27–34 g.
• Plumage: Males feature bright blue heads, backs, and wings with a brownish-red breast; females are duller with grey on the head and back, blue wings and tail, and a lighter, more orange breast.
• Vocalisations: Males produce calls that include soft warbles of jeew or chir-wi, and sing a melodious chiti WEEW wewidoo.
• Behaviour: Often observed perched conspicuously on wires, branches, or fence posts, and will flick their wings while warbling when a predator is nearby.

Habitat

Found across eastern North America, from southern Canada to the Gulf states and as far south as Nicaragua, with an isolated population in Bermuda. They prefer open country with scattered trees but little understory, such as pastures, agricultural fields, suburban parks, and golf courses.

Diet

Adults consume a diet consisting of roughly two-thirds insects and other invertebrates, including grasshoppers, crickets, beetles, earthworms, and snails, with the remainder made up of wild fruits and berries. They forage by perching on high points such as branches or fence posts before swooping down to catch prey on or near the ground.

Did you know?

Although early settlers believed the eastern bluebird was a pre-colonisation resident on Bermuda, a 2013 study using molecular evidence and simulations suggests the island population likely descended from a single, very small founder group during the 1600s, either through natural migration or anthropogenic introduction.