Viceroy Butterfly At Tommy Thompson Park

Over the previous few weeks, Bob and I have made countless trips to Tommy Thompson Park, in Toronto, Ontario, in search of Monarch Butterflies, caterpillars and their elusive cocoons.  On one visit, another Monarch Butterfly landed on a bush right in front of me, or so I thought until I got a closer look at its wings.  The brightly-coloured orange butterfly turned out to be a Viceroy butterfly (Limenitus archippus).

A Viceroy Butterfly can be distinguished from a Monarch Butterfly by its smaller size and the horizontal black line that runs across the veins on each of the back wings.  This Monarch mimic benefits from its similar colouring because predators avoid Monarch Butterflies owing to their bad taste and mildly toxic qualities.  It turns out, however, that Viceroy Butterflies have been discovered to taste equally as unpalatable so birds likewise steer clear of them making this a case of Mullerian mimicry where each species’ traits benefit the other.

Throughout my life, I had never come across a Viceroy Butterfly even though I grew up and have lived where poplar, willow and aspen trees are common, representing suitable habitat for this species.  These types of trees play an important part in the life cycle of Viceroy Butterflies.  Their larvae eat the leaves and catkins of both willow and poplar, so the females lay their eggs on the tips of those leaves.  Whereas Monarch Butterflies acquire their bitter taste from the Milkweed Plants upon which their larvae feed, it is the Salicylic Acid in leaves of poplar and willow that becomes concentrated in the bodies of Viceroys turning their succulent bodies into a rather bitter meal for any careless bird.

The wet meadows, shrubby areas and marshy habitats of Tommy Thompson Park provide the type of conditions and vegetation that Viceroys prefer, but studies have shown that these butterflies are usually outnumbered by Monarchs even where conditions area ideal.  A cyclist happened by just as this Viceroy began basking in the sun, and true to his prediction, the butterfly flew away before he had the chance to snap a photo with his cellphone.  My camera was at-the-ready hanging from its perpetual location around my neck.  The angle and light set off the single row of white dots in the black marginal band of the wings.

The wingspan of a Viceroy Butterfly is between 2.5 – 3.0 inches (6.3 – 7.5 cm) wide.  These striking butterflies do not migrate like Monarch Butterflies but instead, late summer larvae overwinter encased in a protective sheath consisting of a rolled leaf tip from its host plant.  The overwintering larvae complete their life cycle in the spring, which requires about 15 days.  Adult Viceroys are usually first seen about 15 days after the emergence of new leaves on willows and poplars.

At Tommy Thompson Park, the adult butterflies have a good source of food because there are ample choices of flowers upon which to feed.  They prefer nectar from plants in the sunflower family such as those that line the pathways in the Park…wild asters, goldenrod, and thistles…and they will also feed on manure and carrion.

Bob and I were extremely lucky to find a Viceroy Butterfly as they are in danger of becoming extinct due to loss of habitat.  We can be thankful for the naturalized reaches of the Leslie Street Spit because it provides excellent habitat for many different species of animals.   On our next visit to the Park, we were not so lucky.  Viceroy Butterflies were nowhere to be seen.

Related:

A Flutter of Monarch Butterflies At Toronto Shoreline

Monarch Butterfly Chrysalis At Tommy Thompson Park

Frame To Frame – Bob and Jean