First Butterfly of Spring

When I went outside this morning, I spotted this Mourning Cloak (Nymphalis antiopa). It obligingly hung around while I ran back inside and got my camera, and I was able to get this photograph. Mourning Cloaks are among the longest-lived of butterflies, with luck surviving about 10 months. They spend quite a bit of their lives hibernating. The adults emerge from woodpiles, loose tree bark, and other hiding spots and breed in the spring. The eggs are laid in clusters of 30 to 50 in a mass that surrounds a twig. Willows are a favored larval food, but other trees and shrubs are also used. The adults probably die after mating and egg production is complete, and a new generation reaches adulthood about July. The new adults aestivate, the summer equivalent of hibernation, to avoid summer heat and lack of moisture. They re-emerge in the fall and feed and prepare for winter hibernation. It is possible there are two generations produced over the summer in some areas.

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Cryptic Killdeer

I could hear a Killdeer (Charadrius vociferus) calling from the field and took my camera to capture a picture of him. This proved harder than I anticipated because, looking through the viewfinder, it was difficult to see the Killdeer against the background of the field. The above photograph gives a good idea of how well the bird blended into his surroundings. The colour pattern of the Killdeer is termed disruptive. The two bands of black and white on the head and neck break up the outline of the bird and make it more difficult to see against a variegated background.

Killdeer nest on the ground, so their cryptic colouring serves an important function. The nest, often situated in an open area with little surrounding vegetation, is little more than a scrape in the ground, with little or no grass lining. The buff-coloured eggs are marked with a blackish-brown pattern that helps to conceal the nest against a pebble or gravel background. If it is very hot, Killdeer may soak the feathers of their bellies and use them to wet the eggs to keep the developing embryos from overheating in their unshaded nest. Killdeer young don’t need a home as sturdy as a robin’s nest because the hatchlings are precocial. They follow their parents soon after birth and find their own food. They are able to fly in about 25 days after hatching. The Killdeer’s well-known broken-wing display, also used by other shorebirds and waterfowl and ground-nesters, is a devise to lead intruders away from the unconcealed nest.

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