Above: Migrating male Chestnut-sided Warbler, Bois des Esprits, Winnipeg, 17 May 2024; by Peter Taylor.
How do I recognize it?
An adult male Chestnut-sided Warbler’s many field marks include a bright yellow cap, boldly striped back and wings, and a rich brown, finger-painted stripe down the side of its breast. The adult female’s colour scheme is similar, but a little subdued. Juveniles could be mistaken for a completely different species: greenish above and grey below with bold, whitish eye-rings and wing-bars. The male’s primary song has the sweet quality of a Yellow Warbler, terminating with a downward flourish, sometimes written as “Sweet, sweet, pleased to meet-cha” or similar phrases.
Above: A tired migrant alongside the Seine at Whittier Park, Winnipeg, 15 May 2026; by Peter Taylor.
Does it migrate?
Yes; Chestnut-sided Warblers are normally present in Manitoba only from mid-May to mid-September. Their winter range is in and around Central America and the western Caribbean islands.
Above: A perky male Chestnut-sided Warbler in a leafing oak tree at Walter Chryplywy Nature Park, Beausejour, 25 May 2015; by Peter Taylor.
Where does it live?
Chestnut-sided Warblers breed primarily in young or stunted deciduous forest from central Saskatchewan to the Maritimes and northeastern United States.
Above: A male Chestnut-sided Warbler in full song at English Brook, 27 May 2015; by Peter Taylor.
Where can I see it?
During spring migration in mid- to late May, and again in fall, Chestnut-sided Warblers, along with many other warbler species, grace wooded urban parks and gardens with their presence. Their Manitoba breeding range is primarily in the southern boreal forest and aspen parkland. Males often sing in understory and saplings, making them easier to spot than many warblers. Good localities to find them include Whiteshell Provincial Park, Agassiz Provincial Forest, and wooded areas of the southern Interlake and southwestern Manitoba. Their preference for partly cleared areas often brings them close to roadsides.
Above: Juvenile Chestnut-sided Warbler at Grand Beach, 15 September 2007; by Peter Taylor.
Conservation Status:
Manitoba populations of the Chestnut-sided Warbler appear to be stable, though Breeding Bird Surveys indicate some broader, range-wide declines. The species often benefits from regrowth of shrubbery and deciduous forest following fire, logging, or quarrying activities.
Above: Female Chestnut-sided Warbler starting to moult at Pinawa, 1 July 2015; by Peter Taylor.
Did you know:
While many wildlife species declined or even disappeared following European colonization and land-clearing in eastern North America, the population of Chestnut-sided Warblers is thought to have expanded because of their preference for areas of partial clearing and young regrowth. More recently at a local level, this warbler became especially prominent in young deciduous stands near Big Whiteshell Lake after the salvage logging campaign following a 2007 windstorm.
Written by Peter Taylor