Acadian flycatchers have been known to make pair bonds that last multiple years, with the pairs usually returning to the same nest as the previous year and younger birds typically dispersing to other sites. Polygny has occasionally been documented in Acadian flycathchers but they are primarily socially monogamous. Acadian flycatcher courtship behavior occurs between April and August and involves swift, frantic chasing of the female by the male. The male will also hover over the female while she is perched on an exposed branch. Territorial males will frequently sing throughout the breeding season, while females tend to only sing occasionally, and both sexes frequently call to each other. When defending nests, vocalization rate and aggression increase. These tactics are usually successful against nest predators but not against brood parasites.
Mating System: monogamous ; polygynous
Acadian flycatchers reach sexual maturity at 1 year (similar to other Empidonax species). Breeding occurs in the United States between May and August. Females can have 1-2 broods each season, with each brood yielding 2 to 4 eggs. Incubation lasts only 13 to 14 days. Once hatched, the helpless young are cared for by both parents for 13 to 15 days until they fledge. After leaving the nest, young are cared for by both the female and male for another 12 days; if the female begins to incubate another clutch, the young will be taken care of solely by the male.
Breeding interval: Acadian flycatchers typically have 2 broods during the breeding season.
Breeding season: Acadian flycatchers typically breed from late May to mid-August, peaking in early June-early July)
Range eggs per season: 4 to 8.
Range time to hatching: 13 to 14 days.
Range fledging age: 13 to 15 days.
Average time to independence: 12 days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
Females choose nesting sites and build nests, usually leaving long streamers of plant debris dangling for concealment. They also incubate the eggs, during which time males will not typically feed them. Once hatched, both parents tend the young over 13-15 days (until fledging), and then for 12 days after fledglings leave the nest. Both parents heavily invest in caring for the young until they reach independence (approximately 27 days after hatching), including defense of the nest and providing juveniles with a diet consisting almost entirely of insects. If the female begins to incubate a second clutch, the fledglings will only be fed and cared for by the male.
Parental Investment: altricial ; male parental care ; female parental care ; pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)
Acadian flycatchers are songbirds. Their distinctive "peet-sah" or "tee-chup" songs can be a great identification tool when trying to distinguish them from other Empidonax species, but these songs can vary depending on the time of day. Communication between Acadian flycatchers can also vary depending on territory. Males will typically become more vocal when in the presence of territorial neighbors, while females tend to remain quiet, especially while on nests. Acadian flycatchers are similar to most animals in perceiving their environment primarily through auditory and visual cues.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Populations of Acadian flycatchers have declined in states such as Minnesota and Wisconsin, as well as in southeastern Canada. This migratory species is protected under the Migratory Bird Act, although there is no national concern for their population since they are still abundant in most of their breeding ranges within North America. Since Acadian flycatchers are interior forest dwellers needing large, intact forests with dense canopies, they are sensitive to habitat fragmentation and deforestation, especially in agricultural areas.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
There is no known negative economic impact of Acadian flycatchers on humans.
There is no known positive economic impact of Acadian flycatchers on humans.
Little information is available on the ecosystem roles of Acadian flycatchers. However, since they are susceptible to negative impacts caused by deforestation, they could be a good indicator species, based on population sizes, of declining forest habitats. Acadian flycatchers are parasitized by brown-headed cowbirds, mites, and deer ticks.
Species Used as Host:
Acadian flycatchers are mainly insectivores, with diets consisting of mosquitoes, flies, insect larvae, small moths, flying ants, small beetles and some spiders. As their common name implies, Acadian flycatchers are adept at catching insects with their beaks from the undersides of leaves and even in flight, using gleaning and hawking tactics. They have been known to occasionally eat fruits such as blackberries and raspberries. Juveniles are fed diets consisting almost entirely of insects.
Animal Foods: insects; terrestrial non-insect arthropods
Plant Foods: fruit
Primary Diet: carnivore (Insectivore )
Acadian flycatchers arrive in the Nearctic region between April and May for breeding. Their range is limited to the United States from the southeastern region of Minnesota to the eastern half of Texas and east to the Atlantic Coast from those two areas. Very small populations of Acadian flycatchers are found in southern Ontario, Canada. During the winter months, Acadian flycatchers migrate south across Mexico and the Caribbean, where they take up residence in the Neotropical region (the most Northwestern regions of Colombia, Ecuador, and Venezuela). Acadian flycatchers are considered native to these areas and have not yet been found as an introduced species in any region.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
Acadian flycatchers have very specific habitat requirements. Breeding habitats include mature, deciduous forests with thick, shaded canopies and open understory, typically situated near wetland habitats such as streams, ravines or swamps. They occupy the lowest tree canopy and understory layers of the forest and are considered to be interior forest dwellers. Acadian flycatchers usually build hammock or cup-like nests 3 to 9 m above the ground in forks of horizontal branches of trees and shrubs. Nests are built with plant stems and fibrils and held togeter with dried grass stems and spider silk. They will also adorn their nests with "nest tails" (hanging plant debris) for concealment. It is not uncommon for nests to be built over water in ravine settings or in areas where the understory is open (for better nest defense). During non-breeding season, Acadian flycatchers winter in lowland tropical forests of South America.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest
Wetlands: marsh ; swamp
Other Habitat Features: riparian
The greatest lifespan of an Acadian flycatcher recorded in the wild is 10 years and 11 months, and the expected lifespan is approximately 10 years and 9 months (remarkably long for a small bird). Lifespan in captivity is undocumented.
Status: wild: 10.92 (high) years.
Status: wild: 10.75 years.
Acadian flycatchers can be difficult to distinguish from other members of the genus Empidonax (commonly confused with alder flycatchers (Empidonax alnorum), yellow-belied flycatchers (Empidonax flavivenris), willow flycatchers (Empidonax traillii), and least flycatchers (Empidonax minimus)). Adult Acadian flycatchers are small in size (13 to 15 cm) with a triangular head. They are olive in color with white and sometimes yellowish flank and belly areas, white bars (typically two) on their wings, a black upper mandible, and a yellow to pink lower mandible. Acadian flycatchers also have a distinct, thin, white ring around each eye and this, along with their distinctively different voices, habitats and breeding habits, helps to distinguish them from similar species. Juvenile Arcadian flycatchers tend to be more brownish in color than adults, with buff-edged feathers. Their wing bars are also a darker buff than those of adults.
Range mass: 11 to 14 g.
Range length: 13 to 15 cm.
Average wingspan: 23 cm.
Sexual Dimorphism: sexes alike
Other Physical Features: endothermic ; bilateral symmetry
Although their nests are built in a messy fashion with streamers of plant debris hanging off the nest (a tatic used for concealment), nest predation has been known to occur in this species from animals such as accipters, red-shouldered hawks, red-tailed hawks, broad-winged hawks, American crows, blue jays, black ratsnakes, cats, southern flying squirrels, mice, squirrels, barred owls, and chipmunks. This, along with brood parasitism by yellow-billed cuckoos and brown-headed cowbirds, is the main cause of nest failure.
A small (5 ½ inches) flycatcher resembling several related species in the genus Empidonax, the Acadian Flycatcher may best be separated from its relatives not by appearance, but by its ‘pit-see!’ song. Physical field marks include a green-gray body, white eye ring, pale breast, thin bill, and white wing bars. Male and female Acadian Flycatchers are similar to one another in all seasons. The Acadian Flycatcher is a more southerly breeder than most of its relatives, being found in summer in extreme southern Canada and across much of the eastern United States from New York south to Florida and west to Texas. Least Flycatchers spend the winter in Central and South America, although identifying this species’ in much of its winter range is difficult due to its similarity to other related species. Acadian Flycatchers breed in mature deciduous forests and, in parts of the southeastern U.S., in swamp forests dominated by bald cypress. On migration, this species enters younger, more open woodland and forest edges. In winter, Acadian Flycatchers inhabit humid tropical forests. This species primarily eats insects. In northern forests in summer, Acadian Flycatchers are most likely to be seen perching in the forest canopy while gleaning insects from leaves. Even when active, however, the Acadian Flycatcher is a difficult bird to identify. Learning this species’ song is crucial to separating it from its relatives, and silent birds are frequently impossible to identify in areas with multiple Empidonax species. Acadian Flycatchers are primarily active during the day.
A small (5 ½ inches) flycatcher resembling several related species in the genusEmpidonax, the Acadian Flycatcher may best be separated from its relatives not by appearance, but by its ‘pit-see!’ song. Physical field marks include a green-gray body, white eye ring, pale breast, thin bill, and white wing bars. Male and female Acadian Flycatchers are similar to one another in all seasons. The Acadian Flycatcher is a more southerly breeder than most of its relatives, being found in summer in extreme southern Canada and across much of the eastern United States from New York south to Florida and west to Texas. Least Flycatchers spend the winter in Central and South America, although identifying this species’ in much of its winter range is difficult due to its similarity to other related species. Acadian Flycatchers breed in mature deciduous forests and, in parts of the southeastern U.S., in swamp forests dominated by bald cypress. On migration, this species enters younger, more open woodland and forest edges. In winter, Acadian Flycatchers inhabit humid tropical forests. This species primarily eats insects. In northern forests in summer, Acadian Flycatchers are most likely to be seen perching in the forest canopy while gleaning insects from leaves. Even when active, however, the Acadian Flycatcher is a difficult bird to identify. Learning this species’ song is crucial to separating it from its relatives, and silent birds are frequently impossible to identify in areas with multipleEmpidonaxspecies. Acadian Flycatchers are primarily active during the day.
Adults have olive upperparts, darker on the wings and tail, with whitish underparts; they have a white eye ring, white wing bars and a wide bill. The breast is washed with olive. The upper part of the bill is dark; the lower part is yellowish. This bird's song is an explosive peet-sa. The call is a soft peet. They also have a call similar to that of the northern flicker A unique two-note song described as "ka-zeep", and its location in its preferred habitat, are two features that help to identify this species.
The 15 species of this genus were once all thought to be a single species, which was discovered in Acadia in present-day Nova Scotia. Differences in range, voice, and habitat eventually identified them as separate species. The present-day "Acadian flycatcher" is not found in Acadia.
Its breeding habitat is deciduous forests, often near water, across the eastern United States and southwestern Ontario. These birds migrate through eastern Mexico and the Caribbean to southern Central America and the very northwest of South America in Colombia, western Venezuela, and Ecuador.
The numbers of these birds have declined somewhat in the southern parts of their range. Brown-headed cowbirds lay eggs in the nests of these birds in some areas. However, only 16% of cowbird young in Acadian flycatcher nests fledge successfully.
They wait on a perch in the middle of a tree and fly out to catch insects in flight (hawking), also sometimes picking insects from foliage while hovering (gleaning). They may eat some berries and seeds.
They make a loose cup nest in a horizontal fork in a tree or shrub.
The Acadian flycatcher is an excellent flier; it is extremely maneuverable, can hover, and can even fly backward. Curiously, there is no scientific information on hopping or walking by this bird.
As of October 2015 there have been 2 records of Acadian flycatcher in Europe, the first being a bird found dead in Iceland in 1967, and the second a bird found on the beach at Dungeness in Kent, England in September 2015, the latter's identity being established by DNA from its droppings.