The Wood Folk Diaries: Volume 3, Chapter 4: Springs First Butterflies the Mourning Cloak & Compton Tortoiseshell

Dear Wood Folk,

I went back and forth a little on whether to cover our first two spring butterflies, because they aren’t exactly star pollinators. Instead of flower nectar, these two primarily eat sap, the nectar of trees.

It can be quite the surprise to see butterflies fluttering around so early, when nary a flower is out! Here’s a mourning cloak (nymphalis antiopa) and a Compton tortoiseshell (nymphalis l-album) below it:

Mourning cloak (nymphalis antiopa)
Mourning cloak (nymphalis antiopa)
Compton tortoiseshell (nymphalis l-album)
Compton tortoiseshell (nymphalis l-album)

Butterfly, Where Art Thou?

Mourning cloaks usually spend our frigid winter in the barked crevices of trees and similar spots. They start to come out on warmer March days (like the day this post comes out!) For us in Haliburton, that means there is still snow on the ground and frequent flurries at least, as Spring fights to truly arrive. They are soon joined by the four different comma species in our area, who usually come out by April’s end.

Our second featured butterfly today is the Compton tortoiseshell, a “false” comma – the aforementioned true commas look similar though. But tortoiseshells are more common. They are the token “cottage country” butterfly. They overwinter similarly in tree cavities, with an extra penchant for hiding under eaves, or cozied within outhouses and other human structures. In the summertime, you’ll often see them basking in the sun on the sides of these structures too.

If you’re lucky to have a sappy tree like sugar maple in view of your windows, keep an eye out for these butterflies especially where you see the sap running, e.g. fresh woodpecker holes. You may even be lucky enough at some point to see a lot of our overwintering butterflies all at once on a tree. Maybe dozens. I have yet to witness such a gathering.

Plant Allies of Mourning Cloaks and Comptons Tortoiseshells

The graceful mourning cloaks have a lifespan of about one year, one of the longest for butterflies. They have a single generation born every year here. When they’ve woken up in the spring they get busy eating tree sap (especially oak, but also birch, maple, and poplar), fermenting fruits, sugary secretions from aphids, and sometimes flower nectar. They’ve been spotted on dogbane and milkweed, but I am not certain if or what spring ephemerals they may visit. Willow is a good possibility.

Mourning cloaks preferred host plants for their young are various willows and aspen/cottonwoods/poplar. Alder, birch, elm, hawthorn and wild roses may also work around cottage country, Ontario.

The caterpillars cluster together (sometimes that’s called “in an aggregate”) feeding on young foliage. The caterpillars start to wander apart as they get older and usually find a new place to pupate. The mourning cloak chrysalis hangs like a dead shriveled leaf. They emerge in mid summer, but go dormant temporarily. Then they re-emerge in autumn to store energy like a bear for their winter hibernation. Like bears, it’s possible they may emerge on warm winter days for a stretch too. I guess if anyone is the bear of the butterfly world, it’s them.

Comptons tortoiseshells essentially eat the same things as the mourning cloaks, but they for sure feed on the nectar of willow flowers. Willow is also one of our earliest food sources for our bees too! Tortoiseshell host plants are primarily willow, birches, and poplar/cottonwood/aspen. They may also use your apple trees or hop vines. Like mourning cloaks, the caterpillars feed together in an aggregate. Like the mourners, it’s one generation a year. And again, a similar dead leaf looking chrysalis. The new gen flutters around from July to November and then hibernates.

All of our spring butterflies like to gather in muddy spots and on dirt roads to bask in the sun, and they are dark coloured to warm them up faster. They also gather there for “mudpuddling”, which is to get minerals and salts from the mud. Animal scat, compost and other organic matter may be mudpuddled on too.

I’m excited about the next few diaries. Firstly, hummingbird moths are next! Then I get to write about grasses, followed by sedges, and the butterflies that need them. With very few grasses and sedges featured as edible and medicinal, it’s great to have a chance to talk about them and their important role in Nature. Happy Spring!

Please Like, Comment, Share! We'd love to hear your stories and knowledge! Thank you!

Leave a Comment