American Redstart    Setophaga ruticilla

Migratory Status: Neotropical migrant

PIF Population Estimate: 25 000 000

Percent of western hemisphere population breeding in boreal forest: 50%

BAM Effective Detection Radius (m) : 54.84

PIF Maximum Detection Distance (m) : 100

Canadian BBS Population trend: -0.7 n.s. (-1.9 to 0.4)

Life History

The American Redstart is the only member of a monotypic genus (i.e., a taxonomic group with only one species), though it is closely related to many other species of wood warblers in North America. The species is easily distinguished from other warblers by the distinct colour patches in its wings and tail (orange in adult males; yellow in adult females and immatures) and unique tail-flashing foraging technique.

Like only a handful of other North American species, male American Redstarts have delayed plumage maturation. They retain immature plumage until the first definitive basic moult (i.e., adult moult), which occurs on or near the breeding grounds in July or August, typically 14-16 months after hatching. Males reach sexual maturity within the first breeding season (12-14 months after hatching); delayed plumage maturation may reduce competition from more dominant adult males.

The song of the American Redstart is one of the most difficult to identify, largely due to its sometimes fluid nature and highly variable phrasing. The song is often variable between populations and between individuals within populations.

Reference(s)

Sherry, T. W., and R. T. Holmes. 1997. American Redstart (Setophaga ruticilla), The Birds of North America, No. 277. A. Poole and F. Gill, eds. The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists's Union, Washington, D.C.