The western tiger swallowtail butterfly is an abundant species native to a large portion of North America’s northernmost and southernmost west coast.

These butterflies are frequently observed from northwestern regions of Canada down to the southern tip of Baja California and extends eastward through states like the Dakotas, Colorado, and New Mexico.

Young caterpillars resemble bird droppings, and as they molt, they eventually turn bright green, with a pair of large yellow eyespots with black and blue pupils.

Butterflies emerge from winter chrysalids between the spring months of February and May, the date depending on the temperature, so they are seen earlier in the more southerly and more coastal parts of their range.

The life cycle of tiger swallowtail butterflies begins when a female carefully lays individual eggs on different host plants, ensuring that the larvae have enough space and resources to thrive without overcrowding.

Their developmental success at higher latitudes has been attributed to their ability to feed on a diverse variety of host plants, extending beyond the tropical families that the majority of swallowtails rely on.

These butterflies exhibit a seasonal flying pattern, with males emerging in the spring to mate with females, who then lay fertilized eggs on host plants.

They typically have one to three generations each year, depending on the region, and adult butterflies tend to be smaller in colder climates, allowing for better survival in shorter growth seasons.