Alberta Fritillary (Boloria alberta) (W.H. Edwards, 1890)
Diagnosis: This is one of the largest (wingspan: 35 to 45 mm) and dullest-coloured of the lesser fritillaries. It is best recognized by its drabness. Males are dingy orange on the upperside and females are mostly brownish. The hindwing underside is buffy orange with a pale white band tinged with tan.
Range: The Alberta Fritillary has one of the most restricted ranges of any North American fritillary. In Canada it is confined to isolated colonies along the Front Range of the Rocky Mountains in Alberta and on a few mountains just across the border in British Columbia. It occurs in the U.S. in northern Montana.
Early Stages: These have not been described. However, adult females have been reported to lay eggs on Mountain Avens (Dryas octopetala) and adults in the wild are often seen around this plant (Scott, 1986).
Abundance: This species is considered one of the most difficult butterflies to find in Alberta in its remote high-mountain habitat (Acorn, 1993).
Flight Season: This butterfly has a very short flight season in July and early August. It generally only flies in even-numbered years.
Habits: The Alberta Fritillary should only be looked for on high, windswept scree slopes in the Rocky Mountains. It flies for only a few weeks, close to the ground looking for flowers and mates. It is difficult to follow because it prefers steep scree slopes with loose rocks.
Remarks: The present distribution of this butterfly is probably the result of its status as a relict species surviving the last Ice Age. It is likely that it was restricted to small refuges of vegetation high in the Rocky Mountains surrounded by massive sheets of ice. When the ice retreated, it remained isolated in these localities.
© 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.
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