Spring Azure, Henne

One of my favorite Robert Frost poems is called "Blue Butterfly Day," and it's a perfect description of this still-early-spring afternoon when the air has yet to lose its winter bite, you need to keep the wood stove going, and, all floral and bird evidence to the contrary, it remains hard to fully believe in the season. But then you spot small patches of blue sailing low to the ground—"flowers that fly and all but sing"—and that lack of faith disappears... at least for a few moments. The Spring Azure is one of the first butterflies to appear, and, like the bigger, showier Mourning Cloak, it overwinters as an adult so it can get down to spring business as early as possible. A little later in April, it will have some blue competition—in the eyes of butterfly watchers, anyway—in the form of the Eastern Tailed Blue, a similar-looking species at a quick glance, but separable, if the lepidopterans give you a chance to look close, by the latter's spot of orange and, of course, by its trademark tail-like projection on the hind wings.