Olive-sided Flycatcher (Contopus cooperi)


Olive-sided FlycatcherThe Olive-sided flycatcher has seen an overall loss of close to 70% of its population in the past forty years. In King’s Canyon National Park, Olive-sided flycatchers were observed in the 1930’s but not in the 1980’s and they have not been seen in what otherwise appears to be suitable habitat (Marshall). Olive-sided flycatchers have historically depended on postfire habitats, and it has been suggested by scientists that logged forests may actually be an ecological trap for the species. An ecological trap is defined as a habitat that is “low in quality for reproduction and survival that cannot sustain a population yet is preferred over other available, high-quality habitats.” This can occur due to a heavily logged forest looking similar to a post-burn forest, though they obviously function quite differently. Salvage logging, by reducing snag densities, diminishes the habitat that Olive-sided flycatchers prefer. Clearcutting poses a great risk to the species due to the near certainty that any individuals present in that forested area prior to logging operations will flee once operations begin.


The preferred habitat of the Olive-sided flycatcher consists of mid-to-high elevation montane and coniferous forests. Presence in early successional forests seems to depend on availability of snags or live trees that provide suitable foraging and singing perches. It is frequently found along wooded shores of streams, lakes, rives, ponds, and bogs, where natural edge habitat occurs and standing dead trees often are present. The Olive-sided flycatcher likes forested areas with neighboring moist areas, such as meadows. They like to perch on dead branches of live trees or snags. Primary Olive-sided flycatcher habitat includes the presence of forest openings and mature forest, and the presence of snags. Olive-sided flycatchers use both early successional forests and old-growth forests, but intermediate successional stages are generally not suitable.


The Sierra Nevada Ecosystem Report categorized the Olive-sided flycatcher as a species perilously in decline in the Sierra Nevada. Wildland fire use, especially moderate and high-severity fires, creates Olive-sided flycatcher habitat. Suppression activities on the other hand can reduce habitat availability. Salvage logging must be avoided due to its tendency to reduce snag densities and remove larger snags which the species prefers. Clearcutting of forests is certain to remove Olive-sided flycatchers from that previously forested area. The species is generally absent in larger clearcut forests so any logging operations of this type can not be executed if population stability or an increase in the numbers of Olive-sided flycatchers is the conservation goal.


At the national level, both federal management agencies and national conservation organizations have listed the Olive-sided flycatcher as a sensitive species or species of concern. The U.S. Fish and Wildlife Service (USFWS) currently lists the Olive-sided flycatcher as a Species of Conservation and it was listed as a bird species of conservation concern for the USFWS Sierra Nevada Bird Conservation Region.

Scientific Research

Kotlier, N.B. 2007. Olive-sided Flycatcher (Contopus cooperi): A Technical Conservation Assessment. U.S. Forest Service, Rocky Mountain Region. (1.6MB PDF)

Marshall, J.T. 1988. Birds lost from a giant sequoia forest during fifty years. The Condor 90, 359-372. (1.1MB PDF)

Robertson, B. and R.L. Hutto. 2007. Is selectively harvested forest an ecological trap for the olive-sided flycatcher? The Condor 109:109-201. (263KB PDF)

Supporting Resources

California Department of Fish and Game Natural History Information (URL) --This California state website contains rather limited and old information but is a good basic background composite for the species. Choose from a drop-down list to select the animal you are interested in

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