Oregon Silverspot Butterfly Population Supplementation

Project Description

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...

Project Map

Publicly Accessible: Partially
County: Lane County, OR; Tillamook County, OR
Project Size:
  • 115.04 acres

Project Sites

  • Site 1 (Not publicly accessible)
  • Site 2
  • Site 3 (Not publicly accessible)
  • Site 4
  • Site 5

Goals and Targets

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:

No targeted species were identified for this project.

Conservation Actions

Action Status Start Year End Year
Reintroduce native species In Progress 1998 --
population supplementation


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

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

Quick Facts

Owning Organization


Managing Organization

Oregon Zoo & Woodland Park Zoo
(Local Government)

Contact Information

David Shepherdson (Deputy Conservation Manager)
Oregon Zoo

General Information

Project #: 15504
Last Updated: October 22, 2010

Project Relations


Lewis & Clark College
Newport Aquarium
Northwest Zoo & Aquarium Alliance
Oregon Department of Fish and Wildlife
Oregon Department of Forestry
Siuslaw National Forest
The Nature Conservancy
United States Fish and Wildlife Service


Oregon Zoo Conservation

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