Magdalena Alpine (Erebia magdalena) (Strecker, 1880)

Diagnosis: The wing colour above and below is dull black, with no light markings at all. Both sexes have scattered white hairs and females have scattered white scales on the underside, most heavily near the tip of the forewing. Wingspan: 41 to 45 mm.

Subspecies: There are two subspecies, but only subspecies saxicola occurs in Canada.

Range: Erebia magdalena flies in a few very restricted areas of Montana, Colorado, Utah, and New Mexico, and in Canada in a small part of the Wilmore Wilderness Provincial Park, Alberta, and adjacent British Columbia, in Stone Mountain Provincial Park in northern British Columbia, and on an isolated nunatak in Kluane National Park, Yukon.

Specimen collection data

Similar Species: The Mt. McKinley Alpine (E. mackinleyensis) has reddish patches on the forewing. [compare images]

Early Stages: The larvae are green mottled with black; they are covered with short hairs. The head is dark brown. Females lay eggs on any surface, often on the sides and lower surfaces of rocks. The larvae readily eat lawn grass in captivity and probably feed on any available species of grass in the wild.

Abundance: It varies from uncommon to common but is always very local.

Flight Season: Early July to mid-August, probably biennial at times, although flights occur each year.

Habits: Erebia magdalena inhabits high-elevation boulder fields and talus slopes in alpine scree, usually in areas of large rocks covered with black and yellow lichens.

Remarks: Adults fly rapidly in sunshine from about 10 a.m. to 5:30 p.m. Females have a wandering flight over the rocks, often pausing to bask or nectar. Males chase any dark butterfly that they encounter (Hilchie, 1990). The habit of laying eggs on rocks is shared with other high-mountain species that inhabit rocky screes, including Erebia pluto (de Prunner) in Switzerland and Percnodaimon pluto Butler in New Zealand; presumably the dark rocks absorb and hold heat better than grass leaves.

© 2002. This material is reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.