Viceroy butterfly

The Viceroy Butterfly is a North American butterfly with a range from the Northwest Territories along the eastern edges of the Cascade Range and Sierra Nevada mountains, southwards into central Mexico.
Its wings feature an orange and black pattern, and over most of its range it is a mimic with the Monarch butterfly. It can be distinguished from the Monarch by its smaller size and the postmedian black line that runs across the veins on the hindwing.
The caterpillar feeds on trees in the willow family Salicaceae, including willows, poplars and cottonwoods. The caterpillars sequester the salicylic acid in their bodies, which makes them bitter, and upsets predators' stomachs. As further protection, the caterpillars, as well as their chrysalis stage, resemble bird droppings.