This individual, like many others of the same species across North America, Europe and temperate Asia, was looking for a safe space to wedge itself for the winter. Loose bark, loose shingles, empty buildings or empty woodpecker nests are all possibilities. Protected from icy winter winds and hidden from the view of birds, squirrels and other predators, mourning cloaks then spend the cold months employing a combination of strategies that allow them to avoid freezing solid.

Among these strategies are special proteins and increased sugar alcohols in the blood that act as an effective animal antifreeze. Most butterflies spend a few weeks in the summer as an adult, perishing not long after reproducing. Their offspring overwintering as eggs, hibernating caterpillars or as pupae. The adults of others, such as the monarch, head south for a warmer winter home.

Tree sap and decaying fruit are the mainstay of the mourning cloak's diet. This food source allows the butterfly to find nourishment late into the year, long after the last flowers have died away.

Freeze avoidance adaptations and the ability to take advantage of food sources in early spring and late fall means that mourning cloak butterflies can remain in their breeding territory overwinter. They are the last butterflies you will see in the fall and the first you'll see in the spring. It is not uncommon to see one in March after a bit of warm weather, when there is still snow on the ground. These factors combine to make the mourning cloak one of the more successful butterfly species.

A large butterfly (6-10 cm wingspan), this insect is not only highly interesting but is also very attractive. Its wings are a lovely, velvety, dark maroon on the upperside with marginal violet-blue spots in a band of black topped off by a cream border. The common name arose, apparently, when someone compared the colours and markings on the butterfly to the cloak traditionally worn by people in mourning.

All aspects of this beautiful insect are fascinating but what really had me shaking my head was the fact that I was watching a creature with paper thin, delicate wings squeeze itself under leaves and bark and dirt. Why weren't its wings in shreds? Butterflies, like a snowflake or a flower petal, seem to embody the image of all that is fragile and ephemeral. Obviously, they are made of tougher stuff than we think.

If you look closely at my photograph, you will notice a couple of small tears in one wing. A close encounter with a bird or the barbs on a raspberry bush can render such damage, but did not appear to hamper this specimen in any way.