A long time ago, I remember finding a dead swallowtail butterfly and for years kept it in small cardboard box.
To me, this eastern tiger swallowtail was a beautiful winged treasure washed in yellow, overlain with black tiger-stripes and featuring small but noticeable delicate windows of blue and orange.
I’ve long ago lost the box but I’m reminded of this gem of nature every time I see a swallowtail visiting flower beds in the Shuswap.
Given their large size (our swallowtails are our largest butterflies) and striking markings, they are one of the most recognized butterflies in British Columbia. But what many people don’t realize is that we have at least eight species of swallowtails living with us – more swallowtail variety than in any other province of Canada.
On a recent trip to watch birds at the Salmon Arm wharf, I almost stumbled on a swallowtail as it was taking a deep drink of nectar from a flower in one of the park’s amazing gardens. I quickly adjusted from bird to butterfly-watching and snapped a few photographs with the hope that I would capture the markings that would allow me to identify the species. Luckily, the swallowtail co-operated (for a few seconds) and I had a photo that revealed that I was watching a type of swallowtail that was new to me!
Swallowtails generally have prominent little “tails” on the trailing edges of their hind (bottom) wings. These projections are reminiscent of the long tails we’ve all seen on flying Barn Swallows, thus the butterfly’s name swallowtail. The photo has became my new little treasure. It featured two projecting tails edged in yellowish white on each hind-wing making it a two-tailed swallowtail.
Like all butterflies, two-tailed swallowtails go through four stages of life: egg, caterpillar, pupae and adult. When we see the adults flying from flower to flower they are seeking a mate – either by sight or smell. After mating, the females deposit their fertilized eggs on the plants that become the food source for their tiny hatchlings. Two-tailed swallowtail caterpillars eat the leaves of a variety of plants including willow and poplar – both common along the Shuswap Lake foreshore. Eventually the caterpillar pupates and through the magic of metamorphosis emerges as an adult swallowtail. At one time, it was quite fashionable to have a collection of immaculately arranged pinned butterflies – specimens of beauty and scientifically valuable. Today, butterfly-watching and photography are much gentler pursuits.
I’ve found that the same telephoto lens I use for birds, when combined with patience, lets me take pictures without disturbing a feeding butterfly. I actually snap many photos that include wings open and closed so I can see patterns on the upper and lower surfaces. These photos have become my “specimens” that I can use to compare with the illustrations in my favourite field guide, Butterflies of British Columbia (Acorn and Sheldon, 2006, Lone Pine Publishing). Any binoculars suitable for bird-watching are also great for butterfly viewing. And the best part, you can often watch several species of butterflies, including swallowtails, in your own backyard from the luxury of a lawn chair!
