Whenever a species moves from one place to another as the seasons change, it is migrating. Migrations can occur over long or short distances. Many animals move to new places to mate, find food, or give birth.
The arctic tern, for instance, breeds in the Arctic, then flies south almost nonstop to overwinter in the Antarctic. That adds up to about 40,000 kilometres of wing flapping a year! Other migrations are tiny by comparison. Some toads, frogs, salamanders, and snakes hop and slither just a few hundred metres to the wetlands where they mate. After laying eggs or hatching young, they migrate back into the forest. Bats, caribou, seals, eels, and a lot of other animals migrate as well.
The survival of many migratory insects and birds depends on two habitats or more - often thousands of kilometres apart. The monarch butterfly is a good example. Western monarchs migrate to sunny coastal California for the winter, while eastern and central North American monarchs fly to mountain forests in Mexico. Until recently, these forests were being steadily chopped down. Now the Mexican government is protecting the habitat.
At the same time, however, Canadian provinces have laws stating that "noxious" weeds like milkweed, thistle, and chicory must be destroyed. A weed is considered noxious if it's difficult to control and a problem for agriculture. Unfortunately, the larva of the monarch feeds only on milkweed. It's clear that we have a double duty to protect all habitats used by migratory species.
Here's how you can help:
- Find out if there are laws in your area requiring the destruction of noxious weeds.
- If such laws exist, what plants does your municipality consider to be a problem and why?
- Find out everything you can about these plants. What species depend on them for food? Are any of them migrants?
- Do you suspect that wildlife could suffer because these plants are treated as "outlaws"? If so, lay the foundation for change with a letter-writing campaign. Communicate your concerns to the media, landowners, and the municipal office responsible for weed control.
- Present your findings to your municipal council.