- 7.1–7.9 in
- 1.1–1.3 oz
- Moucherolle à côtés olive (French)
- Pibí boreal (Spanish)
- The Olive-sided Flycatcher is frequently associated with burned forests. The opened area and the abundant snags may help it to catch flying insects.
- When flushed off the nest during incubation, the female often drops down toward ground without beating her wings.
- Defends its nest aggressively. A pair was observed to knock a red squirrel off a nest limb and chase it away.
- The oldest recorded Olive-sided Flycatcher was at least 11 years, 1 month old when it was recaptured and rereleased during banding operations in California.
- Breeds in montane and northern coniferous forests, at forest edges and openings, such as meadows and ponds.
- Winters at forest edges and clearings where tall trees or snags are present.
Flying insects, especially bees.
- Clutch Size
- 2–5 eggs
- Egg Description
- Creamy white or buff with ring of brownish spots on large end.
- Condition at Hatching
- Hatch naked and helpless.
Nest is an open cup of twigs, rootlets, and lichens, placed out near tip of horizontal branch of a tree.
Sallies out from top of tall tree or snag to catch flying insect, and frequently returns to the same perch. Beats large prey on perch.
Olive-sided Flycatcher declined by over 3.3% per year between 1966 and 2014, resulting in a cumulative decline of 81%, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 1.7 million, with 49% spending some part of the year in the U.S., 2% in Mexico, and 51% breeding in Canada. The species rates a 13 out of 20 on the Continental Concern Score. Olive-sided Flycatcher is a Tri-National Concern species, and is on the 2014 State of the Birds Watch List, which lists bird species that are at risk of becoming threatened or endangered without conservation action. Declines may be due to a loss of wintering habitat.
- Altman, B., and R. Sallabanks. 2000. Olive-sided Flycatcher (Contopus cooperi). In The Birds of North America, No. 502 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- Partners in Flight. 2012. Species assessment database.
- USGS Patuxent Wildlife Research Center. 2015. Longevity records of North American Birds.
- USGS Patuxent Wildlife Research Center. 2014. North American Breeding Bird Survey 1966–2014 Analysis.