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Throughout most of Alberta, there are no species that can be confused with the Canadian Tiger Swallowtail. The large size (85 - 100mm wingspan) and black stripe through the middle of the hindwing distinguish it from the Old World and Anise Swallowtails (P. machaon and P. zelicaon). In the extreme southern part of the province, from the Crowsnest region south and east to the Saskatchewan border, three other Swallowtails could be encountered that are superficially similar. The Two-tailed Swallowtail (P. multicaudatus) is larger (wingspan usually over 100mm), has narrower black stripes, and has two rather than one tail per hindwing. Pale or faded female P. canadensis are similar to the Pale Swallowtail (P. eurymedon), but the black stripes of P. eurymedon are much broader, and the ground colour of eurymedon is white or creamy white, never pale yellow. A third species may be present in the Waterton - Crowsnest area, the Western Tiger Swallowtail (P. rutulus), which has yellow rather than red spots along the margin of the hindwing underside. No subspecies are currently recognized. Royal Alberta Museum page

The eggs are smooth, green and round (Bird et al. 1995). Early instar larvae resemble bird droppings, while mature larvae are velvety green with a pair of eyespots and a yellow and black stripe on the mid-thoracic segment (Guppy & Shepard 2001). Pupae overwinter, and are light brown with a darker brown lateral stripe (Guppy & Shepard 2001). Males patrol along forest edges to search for females, often along the canopy or subcanopy of aspen woods, and sip moisture at mud and sand.

Larvae feed on willows (Salix spp.), Trembling Aspen (Populus tremuloides) and cultivated crab apple (Malus spp.). Adults nectar at a wide variety of flowers, particularly dandelion (Taraxacum officinale), cultivated lilacs, dogbane (Apocynum spp.) and Labrador Tea (Ledum groenlandicum) (Hooper 1973).