The olive-sided flycatcher is a medium-sized songbird that breeds in forests across North America. This olive-gray bird with a distinctive white patch on its breast has a loud, quick whistle that can be heard high in the canopy. Olive-sided flycatchers are neotropical migrants that spend their winters in Central and South America before returning to North America each spring to breed.
Breeding Range
Olive-sided flycatchers breed in forests across Canada and the western United States. Their breeding range extends from Alaska across Canada to Newfoundland and south throughout the western mountains and into the northeastern states.
Some key details about the olive-sided flycatcher’s breeding range include:
- Alaska – Found breeding in western, central and southeast Alaska
- Canada – Breeds across Canada from Yukon to Newfoundland
- Western U.S. – Breeds in mountain forests across western states like Washington, Oregon, California, Idaho, Montana, Wyoming, Colorado, Utah, Nevada, New Mexico and Arizona
- Midwestern U.S. – Minimal breeding occurs in the northern parts of Minnesota, Wisconsin, Michigan and Maine
- Northeastern U.S. – Breeds across northern New England, New York, Pennsylvania, West Virginia, western Maryland and western Virginia
Within their broad breeding range, olive-sided flycatchers are found in coniferous and mixed forests, particularly mature forests with tall trees. They are most abundant in spruce-fir forests in Canada and alpine forests in the western mountains.
Wintering Range
During the winter months of November to March, olive-sided flycatchers migrate to Central and South America. Their winter range extends from Mexico south to Bolivia and central Brazil.
Some details on the olive-sided flycatcher’s winter range include:
- Mexico – Winters in southern Mexico
- Central America – Winters in Panama, Costa Rica, Nicaragua, Honduras, Guatemala and Belize
- Caribbean – Found in winter on some islands including Cuba, Jamaica, Hispaniola and Puerto Rico
- Northern South America – Winters in Venezuela, Colombia, Ecuador and Peru
- Brazil – Winters in the central and western parts of Brazil
- Bolivia – Winters in northern and central Bolivia
Olive-sided flycatchers are found in tropical evergreen forests and semi-open habitats during winter. They prefer forests edges and gaps with tall perch trees.
Migration Routes
Olive-sided flycatchers take long migratory journeys of over 5,000 miles between their breeding and wintering grounds each year. They travel:
- Northward in spring, arriving on breeding grounds in May and June
- Southward in fall, departing breeding grounds August-October
Some key migration routes and stopover sites include:
- Spring migration north follows Pacific Coast, across Mexican plateau, through Central America
- Fall migration south follows routes across western mountains, Central America and Caribbean islands
- Stopovers occur along migration routes to rest and refuel, especially forest edges and gaps
Ideal Habitat
Olive-sided flycatchers thrive in the following habitat conditions:
- Mature coniferous or mixed forests with tall trees for perching
- Forest openings, edges, shorelines, gaps to hawk for insects
- Presence of snags and dead branches for perching
- Wetlands, lakes, rivers or burns for foraging
- Elevations up to 10,000 feet in western mountains
Features like a multilayered canopy structure, abundant prey, and suitable nest sites are critical for their breeding success. On migration and in winter, they require rested stopover sites with tall perch trees and plentiful insects.
Nesting
Olive-sided flycatchers build open cup nests high up in coniferous trees. Nesting details include:
- Nests usually 30-100 feet high in conifers
- Builds nest out of twigs, bark, lichens, lined with grasses
- Lays 3-4 cream colored eggs with brown spots
- Incubation is 14-18 days
- Young fledge at 17-21 days old
Both males and females participate in nest building. Females incubate eggs and brood young. Males defend territory and bring food to females during nesting.
Diet
Olive-sided flycatchers are insectivores and feed on a variety of flying insects. Their main prey includes:
- Bees
- Wasps
- Flies
- Butterflies/moths
- Dragonflies
- Beetles
They capture insects on the wing by sallying out from high perches. They also occasionally eat fruits and berries.
Key Threats
Major threats facing olive-sided flycatchers include:
- Habitat loss from logging, wildfires, development
- Climate change affecting boreal forests
- Reduced insect prey from pesticides
- Competition with other species
- Extreme weather on wintering grounds
- Predation and brood parasitism
Olive-sided flycatcher populations have declined significantly in recent decades, prompting conservation concern.
Conservation Status
The olive-sided flycatcher has an IUCN Red List status of Near Threatened. Its total population is estimated at 3.5 million breeding birds.
Conservation actions to protect this species include:
- Protecting breeding and wintering habitat
- Sustainable forest management
- Restricting pesticide use
- Monitoring populations
- Researching threats
Increased habitat protection and management will be key to ensuring the future survival of olive-sided flycatcher populations.
Conclusion
In summary, the olive-sided flycatcher is a migratory songbird that breeds in mature forests across Canada and the western United States. It winters in Central and South America, migrating over 5,000 miles each way. Olive-sided flycatchers prefer coniferous forests with tall trees and open areas for hunting insects. They build elaborate cup nests high in trees. While olive-sided flycatcher populations are declining, conservation efforts focused on protecting habitat can help ensure the future of this iconic forest songbird.
