Eco-Journal, v.17.3 May/June 2007Eco-Journal, v.17.3 May/June 2007
Mourning Cloak, Nymphalis antiopa. Photo by Sheila W.
By Lindy Clubb
On a recent trip to the University of Manitoba´s Delta Marsh Field Station, I was delighted to hear the steady chorus of wood frogs, watch wood thrushes pick over the piles of snow on the sandy shoreline of the lake, and listen to the songs of returning migratory birds, which are several octaves higher and much more complicated than the honks of geese. Then I saw butterflies. Butterflies when there was snow in sheltered places, and we still needed wool blankets at night? Those can´t be Mourning Cloaks or Tortoise Shells, I thought, although I had spent time with entomologists and had dog-eared my copy of The Butterflies of Manitoba.
But, they were large colourful Mourning Cloak and Tortoise Shell butterflies, and they are the first of the order Lepidoptera to appear in the early spring. They fly so early since they hibernate over the winter, and they come out on sunny afternoons with as much exuberance as children. Both of these butterflies overwinter as adults hidden in crevices of bark or rock, and they emerge to feed on sap from tree wounds and stumps, or the nectar from early flowers on trees.
Mourning Cloaks have two inch wide deep purple wings edged with yellow, and their flight pattern (like hawks), is to take a few rapid flaps and then glide. When they mate, they spiral up in the air and then one drops to the ground suddenly, while the other one slowly glides down. It´s quite a sight.
Tortoise Shells resemble calico cats in color, with marbled grayish brown wings. They fold these wings when they rest and are well camouflaged by the forests they inhabit.
Milbert´s Tortoiseshell, Aglais milberti. Photo by David Cappaert
By late spring they´ve mated, laid eggs and died, leaving the coming winter for the next generation. They´ve lasted about ten months. The larvae feed on a wide variety of tree species (cottonwoods, birch, elm, willow and aspen) and if you spot a caterpillar that´s black with white speckles, has a row of red spots, and sports branched spines, it´s a Mourning Cloak butterfly to be. The Tortoise Shells produce pale green larvae, also with numerous branched black spines. Birds beware.
Between the butterflies, bird nests, ducks, herons and the sunsets and sunrises over the lake, plus a little dip-netting excursion to a nearby pond, I can see why people are attracted to both the wildlife and the accommodation on Lake Manitoba´s shoreline. The marsh is just as magnificent, and the canoes stacked by the dock invite paddlers to explore. If you go out in late spring, you´ll know which kind of butterflies are dancing in the winds from the lake, and fluttering by the reeds in the marsh.