Species at Risk

Monarch Butterfly

Monarch Butterfly (Danaus plexippus)

Monarch (bds)

Status in Canada: Special Concern

Status in Ontario: Special Concern

Status at SWCR: Very Common

This iconic butterfly is easily recognized by the distinctive orange and black patterns on its large wings. Caterpillars have a distinctive look of their own, with bright bands of yellow, black, and white along their bodies and a pair of filaments at either end.

Quick Facts:

  • It migrates between southern Canada and Mexico in the fall: It takes an average of four generations to make a round trip. In Canada, they are abundant during the summer in Southern Ontario and Quebec.
  • Between August and November, these butterflies cluster by the thousands on trees at specific locations called “staging sites” in preparation for their long migration south. Some nearby staging sites include Point Pelee, Rondeau and Long Point.
  • Monarch caterpillars feed exclusively on the leaves of milkweed species: when we kill these plants, we kill the butterflies too!

Threats at the St. Williams Conservation Reserve:

Loss of host plants: the widespread elimination of milkweed species with herbicides and pesticides in Ontario has cut off the food source for monarch caterpillars.

Activities that can damage critical host plants and their habitat include:

  1. Activities that can introduce or encourage the growth of invasive plants, such as dumping of garden waste and off-trail ATV use.
  2. Activities that kill understory plants such as herbicide application, and unauthorized plant collecting.
  3. Off-trail recreational activities that can trample plants, or remove them from their habitat, such as trampling, crushing under vehicles, and collecting.

St. Williams Conservation Reserve management practices:

  • Population monitoring
  • Forest thinning activities
  • Invasive plant control
  • Enforcement of unauthorized trail use
  • Prescribed burns

What you can do to help:

  • Follow the  code of conduct for recreational activities in the Conservation Reserve and know and respect the current trail-use regulations.
  • Clean your boots, bicycle tires, or ATV before and after visiting the SWCR or other natural areas to avoid spreading invasive plant seeds.
  • Report sightings to the SWCR CC, or the Natural Heritage Information Centre.
  • Report unauthorized trail use or any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).

More information:

Species At Risk Public Registry Profile

Ontario Species at Risk Profile

Funding for this project was provided through the Species At Risk Stewardship Fund