Least Sandpiper, Calidris minutilla

The top two pictures are of spring migrants passing through in breeding plumage.

The birds on the left and below are adults in Fall migration. The color is never as bright as that of the fall Westerns, and sometimes there's very little of it as a result of wear.

Above and left are more Fall adults. The two birds above is mostly molted -- notice the new plain mantle and scapular feathers with light scalloping overlapping the dark worn breeding plumage feathers.

This adult bird, mostly molted to winter plumage, displayed an alert upright stance. Least Sandpipers are usually crouched over, like a little mice. The "standing tall" posture is characteristic of the Long-toed Stint, a Eurasian species that would be a great rarity here. But plumage, bill, and leg color all indicate that this is an otherwise orthodox Least. Below is another unusually upright Least, this one still in breeding plumage in July.

Left and above, two juveniles. They are brighter than breeding plumage adults, with fresh buff scalloping on the feathers, and white linings on some scapulars that create the effect of a horizontal white line along the upper back. Below, a less colorful juvenile, still with fresh buff linings and the white lines.

Two winter plumage birds here, molted already in late August.  I think these are two pictures of the same bird;  can't remember for sure; I was taking a lot of pictures of a lot of Leasts in a pool at sunset.

Left and below, more Leasts in fresh winter plumage, September.

Left, a Least (r) with a Western Sandpiper, both in winter plumage in November. The reflections show the much more extensive brown on the breast of the Least. The best-known distinguishing field-mark, the leg color, yellow in Least and black in Western, is also visible -- but it often is not, with legs in water or covered with mud.