The Oregon Giant Earthworm and Other Native Earthworms

The Oregon giant earthworm (Driloleirus macelfreshi)is a Species of Concern that is endemic to the Willamette Valley of northwestern Oregon. This unique earthworm species, which can grow to be over 4 feet long, is currently known from fewer 15 sites. The most recent finding was made by Dr. Jennifer Gervais ( of a 51" specimen found in a bottomland hardwood forest adjacent to the Willamette River. The rarity of this endemic earthworm is believed to be due to the species apparent requirement for undisturbed soils and its narrow range of tolerance for soil conditions.

For the most recent update on the ecology and conservation of the Oregon Giant Earthworm, visit Xerces Fact Sheet:

The primary objectives of the Native Earthworm Project were to: (1) evaluate the status of and threats to the Oregon giant earthworm (OGE) by assessing its current distribution and abundance; (2) develop protocols and train biologists, both students and professionals, for detecting and identifying the species since other large earthworms seen in the Willamette Valley can be mistaken for this taxon (3) develop preliminary conservation measures for the species; and, (4) educate land owners and managers about the species and its status and conservation needs on their lands. As part of the study, we will gain insights into the ecological and habitat requirements of the Oregon giant earthworm, and means for further study.

Field Project Leader:
       Dana Bailey

       Bill Fender
       Dorothy McKey-Fender
       Judy Jacobs, US Fish and Wildlife Service
       Jimmy Kagen, Oregon Natural Heritage Program

       U.S. Geological Survey, Biological Resources Division
       U. S. Fish and Wildlife Service