The Olive-sided Flycatcher is an uncommon but regular migrant through Arizona, with a few individuals lingering into the breeding season in suitable montane habitat. This large, stocky flycatcher is easily recognized by its dark flanks that frame a contrasting white breast and belly, creating the distinctive “vested” appearance. It often perches conspicuously at the tops of tall snags, from which it sallies out to capture flying insects, returning repeatedly to the same perch.
In Arizona, Contopus cooperi is primarily encountered during spring and fall migration, moving through riparian corridors, forest edges, and highland clearings. Breeding within the state is rare but has been documented at higher elevations in the White Mountains and other coniferous forest regions where tall spruces and snags are available. During migration, individuals may also be found at lower elevations, particularly near water sources that attract insect prey.
The species has experienced widespread declines across North America, attributed to habitat loss, changes in insect populations, and threats on its South American wintering grounds. In Arizona, it remains an uncommon but regular passage migrant.
