Status, Distribution & Conservation

The Monarch Butterfly, Danaus plexippus L., in Canada

Evaluation and Proposed Status of the Monarch in Canada

The recent designation of three Monarch butterfly reserves should be expanded to include (at the very least) Presqu'ile Provincial Park on the north shore of Lake Ontario and Rondeau Provincial Park on Lake Erie. Both of these parks are significant staging areas for the fall migration and should not be excluded simply because they are not federally-held lands. A review of known staging areas in all Canadian provinces should be completed as soon as possible in order to provide protection of those areas deemed significant. A review of the Weed Control Acts of Ontario and other provinces is of paramount importance. In Ontario, a minimum requirement is the removal of Asclepias as a genus from Regulation 1096, the schedule of noxious weeds. Additionally, the use of herbicides and pesticides to control economically harmful plants must be curtailed in favour of ecologically sound methods of biological control (Ferris 1994). It is obvious that in the case of Milkweeds, one preferred method would be to encourage the suite of herbivores, including the Monarch butterfly, that utilize the plants (Wilbur 1976; Morse 1985; Urquhart 1987). As Fred Urquhart (1987) maintains, if Milkweeds are perceived as noxious weeds then the Monarch butterfly is a beneficial insect.

The level of protection status due the Monarch is difficult to ascertain. As Sutherland's (1994) broad designation has suggested the status will differ greatly from place to place and from year to year. Monitoring both the quality and quantity of breeding habitats, direct counts of Monarchs at various locations across the breeding range and at various times of year, as well as accurate counts of the numbers of migratory individuals at significant staging areas are necessary in order to determine the current status. Since the Monarch is a migratory species it seems fitting to offer it the same protection that is given to migratory birds (e.g. Migratory Birds Protection Act, 1994). Population levels of the Monarch should be closely monitored to determine if greater protection is required. A program to monitor Monarch and Milkweed population levels during the breeding season, possibly as monthly "Monarch Counts" undertaken by volunteers, at various locations across Canada would be beneficial.