Canadian tiger swallowtail
The only reliable way to tell this butterfly from the nearly identical eastern tiger swallowtail is a single unbroken yellow line along the forewing's edge.
| Where | Northern forests, river edges, roadsides |
|---|---|
| Size | 67 to 80 mm wingspan |
| When | May to July |
The Canadian tiger swallowtail is a large yellow butterfly with broad black tiger stripes and a wingspan of about 67 to 80 mm. The only reliable way to separate it from the nearly identical eastern tiger swallowtail is the underside of the forewing, where the pale marginal spots merge into one unbroken yellow band instead of staying separate.
Caterpillars feed on the leaves of birch, aspen, willow and black cherry, and the species produces just one generation a year to fit its short northern summer. Adults fly through open woodland, river corridors and roadsides from late May into July, visiting flowers and damp ground for moisture.
Traits
Habitat
Woodland
Colour
Yellow, Black
Active
Day
To people
Harmless to people; adults visit flowers and damp puddles for moisture.
Activity through the year
Often confused with
The pale spots along the forewing's lower margin stay separated into distinct blocks, instead of merging into one continuous yellow band as in the Canadian tiger swallowtail.
Questions
Is the Canadian tiger swallowtail dangerous to people?
Harmless to people; adults visit flowers and damp puddles for moisture.
When can you see the Canadian tiger swallowtail?
The Canadian tiger swallowtail can be seen from May to July, by day.
Plate retouched from a photo by nancymullin, CC0, iNaturalist Licence
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Butterflies and moths›Swallowtails›Papilio
Last updated 2026-09-27. Every entry is checked against published sources.