Olive-Sided Flycatcher and Pollinator Habitat

Olive-sided flycatchers (Contopus cooperi; OSFL) are designated as a U.S. Forest Service Region 9, Regional Forester Sensitive Species, a Species of Greatest Conservation Need in Minnesota, and a Federally Threatened Species in Canada. Breeding Bird Survey estimates OSFL numbers in North America have declined by -3.1% from 1966-2015, and by -3.88% in Minnesota from 2005-2015. Minnesota State Wildlife Action Plan 2015-2025 (SWAP) identified OSFL as one of six species whose populations are declining due to unknown causes.

This species is native to montane and northern coniferous forests, and is most often associated with forest openings, forest edges near natural or human-made openings, or semi-open forested stands. OSFL are frequently found in burned forest, harvested units, or semi-open lowland black spruce-tamarack forest. They depend on abundant snags for perching and insects, especially bees (Hymonoptera), for prey. Bees have exhibited wide-ranging and dramatic population declines in recent years, which could be a contributing factor to OSFL decline.

This project proposes to restore OSFL habitat by enhancing prey habitat. We identified seven general project areas as timber sale boundaries containing harvested conifer stands (mostly FDn32) adjacent to streams or black spruce-tamarack lowlands.

These areas are at high risk of competition from non-native species. Non-natives such as spotted knapweed and common tansy can outcompete other plants, resulting in a local monoculture that only offers a pulse of flowering resources during a limited time, and not the steady flowering resource throughout the full growing season that results from a mix of species, with greater benefit to pollinators. If OSFL are attracted to the project areas for their habitat structure, but prey abundance is not sufficient, these areas may serve as ecological sinks. Hence our interest in supplemental seeding.

Harvested forest regrows quickly and offers flowering resources for only a short time. In contrast, landings, temporary roads, and skid trails remain in an open condition for a longer time period due to the concentrated disturbance, and thus will make a longer lasting contribution to bee habitat than the surrounding harvested forest. We anticipate these sites to provide suitable conditions for 10-15 years following treatment, and seed from these generations of forbs will be distributed to other forest openings naturally over time.