Least Tern

Leasttern-lewisX520

 Least Terns are  species of special concern because their nesting habitat is declining. They nest on sandy or gravelly beaches in competition with human recreation and development. The breeding colonies are not dense and appear on exposed overwash flats, unvegetated areas within the dune grass community adjacent to beaches. They eat fish and some invertebrates.   

The least terns arrive at the refuge in late April. Courtship typically takes place removed from the nesting colony site, usually on an exposed tidal flat or beach. Only after courtship has confirmed mate selection does nesting begin by mid-May and is usually complete by mid-June. Nests are situated on barren to sparsely vegetated places near water, normally on sandy or gravelly substrates. They scrape a shallow depression in sand, soil, or pebbles. Nests usually have 2 or 3 eggs. Young birds are downy at birth and can walk, but do not leave the nest immediately. They leave the nest when they are four weeks old. The birds leave the nesting grounds by the end of August.

Least terns are small terns about 9 inches long and with a 20-inch wingspan. During breeding, they have a black cap ending at white forehead. They have a short white eye stripe and a yellow bill with black tip. Their backs are light gray and their undersides are white. They have black leading edges to their wings. In nonbreeding plumage, they have black eye stripes extending to back of head, white tops on their heads, and black bills. Young birds have U-shaped marks across back. Immature birds resemble winter adults.