Everyday, the male Canadian Tiger Swallowtail begins it's mission to find females who are able to mate. Once the female is fertilized she must start her search for a host plant to lay her eggs on.

The host plants are most commonly birch trees, black cherries, and aspens. The female Canadian Tiger Swallowtails are sure to lay the eggs on host plants that are about eight feet from the ground. She is also certain to find the exposed leaves on the south side of the plant. By doing so she insures that when the eggs hatch the larvae will be exposed to sunlight, and also protected from the wind. This gives the larvae a better chance of survival. It does so because the direct sunlight speeds the growth of the larvae so they can become fully developed before attacked by predators or parasites.