Species At Risk

Cerulean Warbler

(Setophaga cerulea)


Cerulean Warbler
Cerulean Warbler occurrences map


The Cerulean Warbler is a small songbird – about 10 to 12 centimetres long – with long wings and a short tail. The adult male is deep blue on top, with white under parts and a distinctive blue-black band across the throat. The adult female is blue-green on top, with whitish under parts that often appear to have a yellowish tint, and yellow-white eyebrows. Both males and females have two prominent white wing bars and white tail spots.

These birds usually raise one brood of three or four nestlings each year.

The Cerulean Warbler feeds mainly on insects during the breeding season and on nectar during the non-breeding season. Young birds are fed primarily butterfly larvae.


The Cerulean Warbler’s breeding range extends from extreme southwestern Quebec and southern Ontario west to Minnesota and Nebraska and south to Texas and other Gulf states across to North Carolina.

In southern Ontario, populations appear to be separated into two distinct bands: one from southern Lake Huron to western Lake Ontario, and further north, the other from the Bruce Peninsula and Georgian Bay area to the Ottawa River.


Cerulean Warblers spend their summers (breeding seasons) in mature, deciduous forests with large, tall trees and an open under storey.

In late summer, they begin their long migration to wintering grounds in the Andes Mountains in South America.


In Ontario and the United States, the main threat to this warbler is habitat loss from degrading and fragmenting forests, since it requires relatively large tracts of forest.

On the South American wintering grounds, this bird’s forest habitat is under a high degree of threat from logging.


The Cerulean Warbler receives protection under Ontario’s Endangered Species Act and the federal Species at Risk Act. It is also protected under the federal Migratory Birds Convention Act.

What You Can Do to Help the Cerulean Warbler

  • The Ministry of Natural Resources tracks species at risk such as the Cerulean Warbler. You can use a handy online form to report your sightings to the Natural Heritage Information Centre. Photographs with specific locations or mapping coordinates are always helpful. nhic.mnr.gov.on.ca
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Private land owners have a very important role to play in species recovery. If you find the Cerulean Warbler on your property, you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • Bird Studies Canada is working to advance the understanding, appreciation and conservation of wild birds and their habitat in Ontario and elsewhere. For more information on how you can help, visit: www.bsc-eoc.org.
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.
  • The Carolinian forests of southern Ontario support an amazing diversity of plants and wildlife, including many species at risk. Carolinian Canada is working to help recover species at risk and their habitats. For more information, visit: www.carolinian.org/SpeciesHabitats.htm.

Did you know?

Since this warbler is a bird of the tree tops, it is often best identified from below. Birdwatchers will recognize adult males by the thin dark band that crosses the upper part of the predominantly white breast.

Did you know?

When re-nesting if a first nest fails, the female often recycles spider web from the old nest to start construction on the new nest. Fresh lining is gathered for the new nest, but spider web may be too valuable and time-consuming to waste.

Did you know?

The female Cerulean Warbler has an unusual way of leaving a nest after sitting on it a while, sometimes called "bungee-jumping." She drops from the side of the nest, keeping her wings folded to her sides, and opens her wings to fly only when she is well below the nest.

Did you know?

The Cerulean Warbler takes about four months to travel from its North American breeding grounds to the South American Andes, and another two months to return to Canada and the United States the following spring.

Did you know?

One threat to Cerulean Warblers is “nest parasitism” by Brown-headed Cowbirds. The cowbirds lay their eggs in other species’ nests, and the young cowbirds are fed by the host parents at the expense of their own young.

The Endangered Species Act

Contact your local ministry office

Often the best source of local information on species at risk is your nearest ministry office. Call with your questions or concerns.