Restoration Potential: Still a relatively common species, so potential exists for increasing populations, but full potential unknown until causes for declines better understood. Protecting food plants in migration, breeding, and winter habitats from degradation would be an important component of a restoration program. Given the loss of old-growth forests in the Pacific Northwest and the centuries-long prospect of restoring old-growth stands, further research is needed to understand this species' relationship with old-growth and breeding success in younger-aged forest stands.
Preserve Selection and Design Considerations: Little information available on landscape relationships, such as patch size and area sensitivity. Ranked at moderately high risk of local extinction from forest fragmentation (Lehmkuhl et al. 1991). In northern Idaho, negatively associated with fragmented old-growth cedar-hemlock forest, and more abundant in continuous old-growth (Hejl and Paige 1993). Will nest in coniferous forest and forage in nearby meadows and openings, using ecotones and seral habitats that supply food resources. Positively associated with old-growth coniferous forests and forages in early successional habitats and forest openings, but the full spectrum or configuration of habitats important to the species' survival are not fully known. An ample supply of nectar-producing flowers is likely a limiting factor. In the fall, populations migrate south along mountain corridors using high flowering meadows which would be critical to protect from degradation (USDA Forest Service 1994). Regional to international perspective is important given the species' high mobility throughout the seasons following phenology of flowering plants.
Management Requirements: Activities that reduce nectar or insect food sources may be detrimental, such as pesticides and herbicides, some grazing practices, or eradication of flowering shrubs such as RIBES or MANZANITA spp. (USDA Forest Service 1994). Flora of mountain meadows should be protected and grazing in these habitats avoided where it reduces nectar-producing plants.
TIMBER HARVEST: Effects of timber harvest need further study. Density and occurrence positively associated with old-growth coniferous stands in Cascades, Oregon Coast Range, and northern Idaho (Carey et al. 1991, Gilbert and Allwine 1991, Manuwal 1991, Hejl and Paige 1993). In one study, showed a negative response to recent fragmentation of old-growth by clearcuts (Hejl and Paige 1993). In the Rocky Mountains, was more abundant in clearcuts with tall shrubs and in partially cut harvest units than in untreated coniferous forest habitats; equally abundant in low shrub clearcuts as untreated forests (Hejl et al. 1995).
Calder (1993), however, suggests that clearcuts increase seral flower abundance beyond what would normally be found under the forest canopy or in natural openings. Hutto and Young (in prep) suggest that harvest units and other human-altered environments with vegetation structures that do not occur in natural seral habitats may serve as "ecological traps" that attract birds with elevated food resources, but become detrimental to reproduction and survival due to increased predation or brood parasitism. Whether reproductive success in harvest units differs from natural forest stands has not been studied.
GRAZING: Grazing effects mostly unstudied. A negative response to grazing in aspen riparian habitat in California and Nevada reported by Page et al. (1978, cited in Saab et al. 1995). Would be detrimental where grazing reduces nectar-producing shrubs and forbs.
Management Research Needs: Much research has been done on physiology and the coevolution of hummingbirds and flowers, but many areas of natural history and ecology unknown. Further study needed on lifespan and survivorship; disease, nest predation and other sources of mortality; philopatry, territory and home range size; details of habitat relationships; limiting factors. Very little known about the causes of long-term declines in the Pacific Northwest. Need research on effects of land management activities such as timber harvest and grazing, particularly impacts on food resources, nest predation, reproductive success, and survival. Need further research on habitat relationships throughout seasons, such as the importance of old-growth forest stands, successional habitats, or other habitats to breeding, foraging, and survival. Need an understanding of landscape relationships, such as patch sizes, area sensitivity, juxtaposition of nesting and foraging habitats. Information on threats on stopover and wintering sites; further description of migration routes; and details of habitat use during migration and winter all needed. Need information on direct and indirect effects of pesticides, herbicides, and other toxins.