The smallest of the Caladrine sandpipers (genus Caladris) are called “peeps” or “stints”. The least sandpiper (Caladris minutilla) is the smallest of the “peeps”. (The other two common “peeps” are the western and semipalmated sandpipers.) Identification of the Caladrine sandpipers is often difficult. However, the least sandpiper’s small size (barely larger than a sparrow), greenish-yellow legs and black, slightly drooping bill separate it from the other members of the genus.
Adult least sandpipers adults are black and brown above with conspicuous streaks on a brownish breast. The remainder of the undersides are white. There is a white mantle line and a white supercilium stripes that meet at the base of the bill. Males are slightly smaller than females.
These tiny birds are long-distance migrators, with many traveling thousands of miles from their summer Arctic breeding grounds to winter in the southern United States or the northern half of South America, as far as Brazil or Chile.
Least sandpipers can be found in a hunched posture probing for crustaceans, insects and other invertebrates at the edges of mudflats and marshes. They prefer fresh water with vegetation and generally are found on higher, slightly drier ground than other peeps. While probing damp mud with their bills, least sandpipers use the water’s surface tension to move prey from the bill tip into their mouths. When available, the seeds of marsh grasses supplement the least sandpiper’s diet.
Least sandpipers build scrape nests lined with dead vegetation in tufts of short marsh grass on damp ground or on moss hummocks in the wetter areas of the tundra and boreal forests of the Far North. Males and females share incubation, with males assuming most of the responsibility. Females only incubate the eggs in the evening. Chick can feed themselves but the male stays with them and protects the chicks until they fledge.
Leonard and I found these least sandpipers at Ash Creek Wildlife Area in Modoc County CA. It took several trips and trudging across the shallow, muddy ponds before we were able to get close enough to photograph these cute birds. Thankfully they did not continue their northward migration until we were able to photograph them.