Icaricia icarioides fenderi

Overview

Once thought to be extinct, the Fender's blue butterfly was known only from collections made between 1929 and 1937, until Paul Hammond rediscovered it in 1989. Fender's Blue once thrived in the prairies of Oregon, but during the past 140 years an estimated 99 percent of this native prairie has been developed for farmland or other uses.

Habitat loss from agriculture and urban development poses the greatest threat to the Fender's blue butterfly. Another major threat to the butterfly is the invasion of exotic plants. Invasive species, such as Himalayan blackberry (Rubus discolor) and Scotch broom (Cytisus scoparius), have been out-competing and displacing the Kincaid's lupine (Lupinus sulphureus var. kincaidii) and other native wildflowers in upland prairies where the butterflies live.

Description

The Fender's blue is a small butterfly in the family Lycaenidae, with a wingspan of about 2.5cm (one inch). As its name implies, the upper wings of male Fender's blue butterflies are predominately iridescent sky blue. Females have rusty brown wings. The dorsal surface of both sexes have a black border within a white fringe and the underside is pearly gray to dirty chalk, with black and brown spots, outlined in white.

Life History

Fender's blue butterflies live primarily in the upland prairies of Oregon's Willamette Valley. The Kincaid's lupine (L. sulphureus var. kincaidii) - a wildflower formally listed as threatened because of extensive habitat loss - is the primary food source for the butterflies during their caterpillar stage and is critical to the survival of the Fender's blue.

Adult butterflies begin laying their eggs, primarily on the Kincaid's lupine, during the month of May. Once the larvae hatch, the caterpillars feed briefly until the plants begin to senesce in early July. At that time, they drop to the base of the plants and enter diapause (a stage in the butterfly's life when its growth and development are suspended) for the fall and winter. In February or March the larvae come out of diapause and continue their development. The larvae then enter their pupal stage and subsequently emerge as adult butterflies in May. A Fender's blue butterfly completes its life cycle in one year.

Distribution

The Fender's blue butterfly is endemic to the native upland prairies of the Willamette Valley in Oregon. Only one-tenth of one percent of the original habitat once available to the Fender's blue and Kincaid's lupine, or approximately 400 hectares of prairie, exists today.

Conservation Status

The Fender's blue occurs in 32 small sites totaling 408 acres. Twenty-four of these populations occupy sites of eight acres or less. Most of these populations are in decline, and 19 contain fewer than 50 individuals. Fourteen sites are on federal, state, county, or city lands. The remainder are on private lands.

In surveys in 2001 many populations showed declines that are believed to be the result of the previous winter's drought conditions. Benton County had four stable, three decreasing, and one increasing population. Lane County had one stable, three decreasing, and two increasing populations. Active management - including mowing and burning to remove competitive weeds - is occurring at several sites. A recovery plan for Fender's blue, Kincaid's lupine, and Willamette daisy is currently under development by Fish and Wildlife Service.

Conservation Needs

Efforts to restore degraded prairie habitat and remove non-native plants will be critical to this species' recovery.

Working with landowners

Staff from the Oregon Zoo in Portland are working with some landowners who have the Fender's blue host plant (Kincaid's lupine) growing on their property. They have collected seeds from several sites and are experimenting with propagation protocols. If successful, the propagated lupine will serve as a potential source of host plants for restoration efforts and they may serve as food plants for captive reared Fender's blues.

Education

Oregon Zoo staff have begun exploring opportunities for rearing Kincaid's lupine in local schools. However, a formal program has not yet been initiated.

Education sheets available at zoological facilities (e.g. zoos, aquariums, botanical gardens with butterflies, butterfly houses, natural history museums) or events at which BFCI partners participate are a valuable way to disseminate information about imperiled butterflies.

When schools and other youth organizations study biodiversity and species extinctions they typically use examples of charismatic megafauna (e.g. bald eagles) or exotic creatures from the tropics. However, vulnerable species found within the state or ecoregion in which students live provide an excellent opportunity to develop curricular materials with a direct link to the students' home region. In addition to classroom studies, students may be able to visit sites to see the butterflies, as well as talk to the scientists and land managers involved in the species' conservation.

Educational activities that school students and community members could do include:

• studying butterfly (insect) life stages;
• researching the special habitat needs of Fender's blue;
• corresponding or meeting with the biologists managing current Fender's blue sites;
• visiting Fender's blue sites during adult flight season;
• visiting captive breeding programs;
• assisting scientists with on-site habitat management;
• propagating and growing host plants for planting at butterfly sites or use in captive breeding programs; and
• writing letters to decision makers to ensure that the Fender's blue receives adequate resources and protection.

Research

Currently, scientists are engaged in an active research program to study the habitat needs of this butterfly's host plant. In addition, scientists with the Nature Conservancy, with the help of Xerces Society volunteers, are looking for new populations. Staff from the Oregon Zoo are currently raising Puget blue butterflies (Icaricia icarioides blackmorei) with two aims: 1) as a surrogate species to develop husbandry protocols for rearing the Fender's blue, and 2) to conduct experiments in the field comparing the behavior of captive and wild reared adult butterflies. Their hope is to apply the results of this research to all butterfly captive rearing and release programs. This research is being conducted in conjunction with Cheryl Schultz at Washington State University, Vancouver Campus.

Captive Rearing

As detailed in the Research section, work on breeding the Fender's blue butterfly is in its initial stage. Cheryl Schultz, Assistant Professor of Zoology, Washington State University is heading up this effort in conjunction with the Oregon Zoo and other partners.

Recovery Plan

None

For more information

• USFWS Contact: Amy Horstman, Oregon Fish and Wildlife Office, Phone (503) 231-6179, Amy_Horstman@r1.fws.gov
• The Nature Conservancy: Cathy MacDonald, Oregon Director of Conservation Planning, Portland, OR. Phone (503) 230-1221
• Cheryl Schultz, PhD, Assistant Professor, Zoology, Washington State University, Vancouver WA 98686-9600, Phone (360) 546-9525, schultzc@vancouver.wsu.edu
• Willamette Resources and Educational Network: Pat Johnston, Project Manager, Bureau of Land Management, West Eugene Wetlands Project Office, 751 S. Danebo, Eugene, Oregon 97330, Phone (541) 683-6181, pat_johnston@or.blm.gov
• Oregon Zoo: David Shepherdson, Conservation Program Scientist, 4001 SW Canyon Road, Portland, Oregon 97221-2799, Phone (503) 220-5765, shepherdsond@metro.dst.or.us

References and Resources

• Hammond, P. C. 1995. 1994 study of the Fender's blue butterfly (Icaricia icarioides fenderi) in Benton, Polk, and Yamhill Counties. Report to the Oregon Natural Heritage Program and the U.S. Fish and Wildlife Service. 34 pp.
• Hammond, P. C., and M. V. Wilson. 1992. Biodiversity and the conservation of endangered species. Northwest Environmental Journal 8:174-176.
• Hammond, P. C., and M. V. Wilson. 1993. Status of the Fender's blue butterfly. Report to the U.S. Fish and Wildlife Service. 66 pp.
• Hitchcock, C. L., and A. Cronquist. 1973. Flora of the Pacific Northwest. University of Washington Press, Seattle. 730 pp.
• Oregon Natural Heritage Program. 1995. Rare, threatened and endangered plants and animals of Oregon. Oregon Natural Heritage Program, Portland, Oregon. 84 pp.
• Schultz, C. B. 1994. Status of the Fender's blue butterfly (Icaricia icarioides fenderi) in Eugene, Oregon: a species at risk. Report to the Oregon Natural Heritage Program and the U.S. Fish and Wildlife Service. 43 pp.
• Schultz, C. B. 1995. Status of the Fender's blue butterfly (Icaricia icarioides fenderi) in Lane County, Oregon: a year of declines. Report to the Oregon Natural Heritage Program and the U.S. Fish and Wildlife Service. 58 pp.
• Wilson, M. V., P. C. Hammond, and J. B. Kauffman. 1992. The value of restoration and management in protecting biodiversity. Northwest Environmental Journal 8:201-202.
• Double Jeopardy: Endangered Butterfly Depends On Endangered Plants (from CNN.comNewsNet)
• Fenders blue research information. Mark V. Wilson and Oregon State University. 2003.
• USFWS Fender's blue page

back to species profiles

Classification

Federal Endangered Species (Federal Register 65:3875; January 25, 2000)

State Status

No state designation beyond the federal classification.

Range

OR

Critical Habitat

None designated

Acknowledgement

This profile was prepared by the Xerces Society for the Butterfly Conservation Initiative.