The seed pod of a swamp milkweed plant open and ready for distribution.

A monarch caterpiliar munching a seed pod on a swamp milkweed plant.

Monarchs

Monarch butterflies and milkweed plants share a special relationship. Milkweed is host plant for monarchs. The plant serves as self-contained nursery to monarchs. Monarchs lay their eggs on the plants, caterpillars hatch, and consume the plant in their larvae stage.

Milkweed contains toxins that the caterpillars are immune to. By ingesting the plant and it's toxins while developing, the caterpillar absorbs the toxins into it body. Once the transformation occurs to a monarch butterfly, the toxins remain. Monarchs are toxic to birds who are know to munch a butterfly or two as a way of survival.

The toxins are usually not enough to kill the bird, just enough to make them ill. After sampling one monarch and getting sick, birds take note of the pattern on the monarchs wings and avoid them.

The flight pattern of a monarch is smoother then most other butterflies. That is a another signal for birds to stay away. The zig zag pattern of other butterflies is a defense mechanism to make it more difficult for birds to snatch them up as a afternoon snack.

In return for hosting the plant and giving the monarch a virtual pass from predators, monarch pollinate the plant.