Oregon

In 1998 the Oregon zoo initiated a zoo rearing and release population supplementation program for the Oregon Silverspot butterfly. The Woodland Park Zoo joined the effort soon after. Adult females are received from the field (currently Mt. Hebo) each Fall. They are induced to lay eggs which are hatched and the larvae (caterpillars) are overwintered in refrigerators. The larvae are removed in the early summer and fed through six instars before release at sites on the coast. Several thousand are released each year.

The Oregon Zoo also participates in habitat restoration by raising and planting about 10,000 host plants (viola adunca) and nectar plants each fall.

A partnership with Lewis & Clark college has facilitated research on larvae behavior which has been applied to habitat restoration.

Volunteers

Funding

Primary motivations:

Conservation Mission

Inspiring our community to create a better future for wildlife.

Primary goals:

Increase and sustain existing populations size and genetic health.

Progress:

Population size has increased to near pre-crash levels with population supplementation. No new populations have been established to date.

Consistent with plans:

Nature Conservancy Ecoregional Plan

State Wildlife Action Plan

Conservation Strategy Species

Species Recovery Plan

USFWS listed species

Targeted habitats:

• Shrublands and Grasslands
  • Grasslands
    • Coastal and Valley Grassland

Targeted species were not provided for this project.

Is the success of this project's actions being monitored?   Yes

Please describe your monitoring activity.

TNC and USFWS partner to conduct annual population index counts and conduct habitat assessments.