Mardon Skipper

A Washington state endangered species, the Mardon skipper (Polites mardon) depends on native, fescue-dominated grasslands in Washington, Oregon and northwest California. This habitat is now threatened by invasion of native and non-native plants, development, recreational activities, grazing, agricultural practices and herbicides. Restoration of habitat and reintroduction will be important parts of this butterfly's recovery. Captive-rearing to reduce juvenile mortality will support repopulation efforts.

The Oregon Zoo received 30 adult female butterflies in the summer of 2004. Six different housing methods were used to determine the best method for egg laying. Eggs laid in the lab were kept in petri dishes and hatched into 1-millimeter caterpillars.

These larvae were fed fescue and raised into pupae, which were sent to Washington State for release.

Mardon Skipper Fast Facts

• Listed in Washington state as a species of concern, this butterflyis a candidate species for both federal and state protection.
• Lab-rearing project at the zoo started in 2003.
• Eggs are laid on fescue (grass).
• Skipper caterpillars build a “tent” in the fescue to diapause.
• The smallest of butterflies raised at the lab, the Mardon skipper’s average wingspan is less than an inch.