Species At Risk

Prothonotary Warbler

(Protonotaria citrea)


Prothonotary Warbler
Prothonotary Warbler occurrences map


The Prothonotary Warbler is a stunningly beautiful songbird with a brilliant golden-yellow head, throat, and belly. The back is olive-green and the wings, rump and tail are dark blue-grey. The tail shows prominent white spots when spread. Females and juveniles are similar to males, but not as brightly coloured. This species also has an unusually large beak compared to other warblers, which it uses to excavate nesting cavities in rotten wood. Its song is a very clear and rapidly delivered, "Tsweet-tsweet-tsweet-tsweet".

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In Canada, the Prothonotary Warbler is only known to nest in southwestern Ontario, primarily along the north shore of Lake Erie. Over half of the small and declining population is found in Rondeau Provincial Park. In 2005, it was estimated that there were only between 28-34 individuals in Ontario.


In Ontario, the Prothonotary Warbler is found in the warmer climate of the Carolinian deciduous forests. It nests in small, shallow holes, found low in the trunks of dead or dying trees standing in or near flooded woodlands or swamps. They will also readily use properly placed artificial nest boxes. Silver maple, ash, and yellow birch are common trees in these habitats. The Prothonotary is the only warbler in eastern North America that nests in tree cavities, where it typically lays four to six eggs on a cushion of moss, leaves and plant fibres.


The main threats to the Prothonotary Warbler are habitat destruction caused by the removal of dead and living trees, and the draining of the forested swamps that make up their exclusive habitat. Another concern is the continuing loss of wintering habitat, especially mangrove swamps, in Central and South America. Competition from other birds, like the House Wren and Brown-headed Cowbird, is a threat in some areas. Natural factors, such as climate change, storms, and extremes in water levels are also potential issues.


The Prothonotary Warbler and its habitat are protected under Ontario’s Endangered Species Act. This species also receives protection under the federal Migratory Birds Convention Act.

What You Can Do to Help the Prothonotary Warbler

  • The Ministry of Natural Resources tracks species at risk such as the Prothonotary 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).
  • 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.
  • Private land owners have a very important role to play in species recovery. If you find the Prothonotary Warbler on your property, you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • 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.
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.

Did you know?

The Prothonotary Warbler was named after legal clerks in the Roman Catholic Church, known as prothonotaries, who sometimes wear a golden hood and a blue cape.

Did you know?

This warbler is considered one of the most dazzling birds in North America due to its stunning colouration and its habit of feeding along pond edges where it constantly sees its reflection, making it doubly beautiful. One very appropriate folk name for this bird is “swamp candle”.

Did you know?

Prothonotary Warblers spend the winter in the warm, tropical climate of Central and South America. The coastal mangrove forests they favour are one of the most endangered habitats in the world.

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.