Have you checked your lilacs and flower beds lately? If not you are missing a rare treat: when flowers are in bloom, Canadian tiger swallowtails are usually up and about. This species of butterfly is the only member of the worldwide swallowtail family to live this far north.
Lilac bushes will often have two or three-dozen swallowtails fluttering about courting and feeding. Although never quite still they stay put long enough for us to get a good look at them. An excellent opportunity to try out your camera. The best time is in the morning before the butterflies have warmed up and inclined to fly out of focus.
The familiar yellow and black wings and body are a common sight from mid-May until late June. Its strong soaring flight and addiction to garden flowers bring it close to our homes. However, its natural habitat is at the edge of hardwood forests.
Once the adults have dried their wings and warmed their bodies to a point where they can fly efficiently they take off for the day’s activities. The males in search of unmated females and the mated females in search of host plants on which to lay their eggs, most often birch, black cherries and aspens.
The larvae are said to be tasty to birds but swallowtails do have a few tricks to help them survive. The first hatch of larvae arrive in spring before leaves are on the plants and during vulnerable times between molts they look like bird droppings, not a favourite with birds. Later hatches are green to blend with the green leaves. The caterpillar also has a defense system called an osmeteria. The ostromerium, a forked organ behind the head, gives off a foul odour if the caterpillar is disturbed. This feature is unique to swallowtails.
Female swallowtails tend to lay their eggs less than 2.5 metres (eight feet) from the ground on exposed leaves on the south side of host trees. When the eggs hatch, the larvae are exposed to the warm sun and protected from the wind. This speeds up the growth of the larvae so that they have a better chance of completing their development before being found by predators or parasites.
It is common to see large numbers of adults getting liquid from a puddle on roadways. Several species go "puddling" (maybe pubbing) but only the males demonstrate this behavior. What are they looking for and why?
In a few cases the swallowtails are hunting for protein but in most cases it's road salt dissolved in water that they crave. Since the plant material butterflies feed on contains very little salt, they must source it elsewhere; thus the puddling. Females do not partake in puddling because they get most of their salt from the male during mating when salt gets deposited in her eggs.
Until recently the Canadian tiger swallowtail was considered a subspecies of the tiger swallowtail, a species found in extreme southern Ontario. It is now a distinct species-- a unique population living in the yellow birch and aspen forests of Canada. The caterpillars have an excellent chance of survival because they have developed a way to destroy the poisons present in host trees. The tiger swallowtails, southern variety, all die when they feed on the same host trees. Conversely, the tiger swallowtail is able to survive on the tulip trees in the Carolinian forest while the Canadian tiger swallowtail does not do well at all on this vegetation.
Photos by Clayton Rollins
Lilac bushes will often have two or three-dozen swallowtails fluttering about courting and feeding. Although never quite still they stay put long enough for us to get a good look at them. An excellent opportunity to try out your camera. The best time is in the morning before the butterflies have warmed up and inclined to fly out of focus.
The familiar yellow and black wings and body are a common sight from mid-May until late June. Its strong soaring flight and addiction to garden flowers bring it close to our homes. However, its natural habitat is at the edge of hardwood forests.
Once the adults have dried their wings and warmed their bodies to a point where they can fly efficiently they take off for the day’s activities. The males in search of unmated females and the mated females in search of host plants on which to lay their eggs, most often birch, black cherries and aspens.
The larvae are said to be tasty to birds but swallowtails do have a few tricks to help them survive. The first hatch of larvae arrive in spring before leaves are on the plants and during vulnerable times between molts they look like bird droppings, not a favourite with birds. Later hatches are green to blend with the green leaves. The caterpillar also has a defense system called an osmeteria. The ostromerium, a forked organ behind the head, gives off a foul odour if the caterpillar is disturbed. This feature is unique to swallowtails.
Female swallowtails tend to lay their eggs less than 2.5 metres (eight feet) from the ground on exposed leaves on the south side of host trees. When the eggs hatch, the larvae are exposed to the warm sun and protected from the wind. This speeds up the growth of the larvae so that they have a better chance of completing their development before being found by predators or parasites.
It is common to see large numbers of adults getting liquid from a puddle on roadways. Several species go "puddling" (maybe pubbing) but only the males demonstrate this behavior. What are they looking for and why?
In a few cases the swallowtails are hunting for protein but in most cases it's road salt dissolved in water that they crave. Since the plant material butterflies feed on contains very little salt, they must source it elsewhere; thus the puddling. Females do not partake in puddling because they get most of their salt from the male during mating when salt gets deposited in her eggs.
Until recently the Canadian tiger swallowtail was considered a subspecies of the tiger swallowtail, a species found in extreme southern Ontario. It is now a distinct species-- a unique population living in the yellow birch and aspen forests of Canada. The caterpillars have an excellent chance of survival because they have developed a way to destroy the poisons present in host trees. The tiger swallowtails, southern variety, all die when they feed on the same host trees. Conversely, the tiger swallowtail is able to survive on the tulip trees in the Carolinian forest while the Canadian tiger swallowtail does not do well at all on this vegetation.
Photos by Clayton Rollins
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