Monarch Butterfly

Monarch Butterfly, the only BUTTERFLY of the family Danaidae (order Lepidoptera) found in Canada. Because of its migratory habits, it is possibly the best-known, most publicized migratory butterfly. Found in every province and territory, it is only numerous where the host plant MILKWEED (Asclepias spp.) grows. Its large size, orange and black coloration and slow, sailing flight make it a familiar butterfly of such areas.

Migration
The spring migration northwards into Canada is accomplished by the progressive advancement of individuals of successive generations. The legendary fall migration southwards is undertaken by adults of the final summer brood. Monarchs born W of the Rockies overwinter in California; those from central and eastern N America in central Mexico. After 40 years of research, the first Mexican wintering site was discovered in 1974 by Frederick Urquhart of U of T.

Predator Deterrent

All monarchs were originally thought to contain a poison absorbed from their caterpillars' host plant. Recent research on monarchs suggests that since only certain species of milkweed contain these deadly cardiac glycosides, butterflies originating from caterpillars reared on such nonpoisonous milkweeds, eg, common milkweed (A. syriaca) and showy milkweed (A. speciosa) are no longer thought toxic.

The bright coloration associated with the presence of toxic chemicals was said to protect the monarch from predation. Predators feeding on them would learn to associate the toxic effects of the chemicals and foul taste with the colour pattern, and in future would avoid them.

Author BERNARD S. JACKSON

Suggested Reading
F.A. Urquhart The Monarch Butterfly (1960); S.B. Malcolm and M.P. Zalucki, eds Biology and Conservation of the Monarch Butterfly (1993).

Links to Other Sites
Monarca: butterfly beyond boundaries
Find out about the Monarch butterfly exhibit produced by the Canadian Museum of Nature.

Canadian Biodiversity Website
A great information source for all budding biologists. Learn about biodiversity theory, natural history, and conservation issues. From McGill’s Redpath Museum.

Butterflies North and South
Learn about the natural history of Canadian butterfly species and planting butterfly gardens at this extensive Virtual Museum of Canada website.

E-Fauna BC
An extensively illustrated guide to wildlife species found in British Columbia. Covers bats, birds, beetles, bugs and much more. Also features an insect glossary and notes about invasive species. A biogeographic initiative of the Lab for Advanced Spatial Analysis, Department of Geography, UBC.

The Canadian National Collection of Insects, Arachnids and Nematodes
This website provides information about the scope and contents of the Canadian National Collection of Insects, Arachnids and Nematodes. Check the “Index” link for illustrated descriptions of various taxonomic groups.

Monarch butterflies not feeling the love
A news story about the impact of seasonal temperatures on Monarch butterfly populations. From thestar.com.

University of Alberta's E.H. Strickland Entomological Museum
Check out images and information about insect specimens found in the University of Alberta's E.H. Strickland Entomological Museum, one of the most significant insect collections in Canada.

Aquatic Invertebrates of Alberta Online Textbook
An online guide to all major groups of Alberta's aquatic invertebrates. Offers illustrated details of the natural history of each group as well as tips on collecting and preserving specimens. A University of Alberta website.