Chignik River Least Sandpiper

Least Sandpiper Chignik River

Although he’s got some bulk to him, at a mere five to six inches from bill tip to toenail, this ball of white and russet feathers would have to look up to make eye contact with a House Sparrow. But to the tiny crustaceans and other small invertebrates that make up most of his diet, the Least Sandpiper is undoubtedly viewed as a formidable predator. (Chignik River, July 24, 2020)

The Least is our smallest sandpiper, which makes it, I believe, our smallest shorebird. In fact, until a flock of them takes flight, they can easily be overlooked on pebbled shorelines where their size and plumage allow them to blend in almost perfectly. On the other hand, they’re numerous and widely distributed, making them one of the more frequently encountered peeps. In addition to their tiny size, look for yellowish legs. This characteristic distinguishes them from Western Sandpipers and most other similar birds which generally have dark legs. They use their long, slightly down-curved bills to probe mud, sand and silt or to glean suspended minutia from the water surface. Often found among flocks of other waders, it is reported that Least Sandpipers tend to feed a little higher up the flat or shoreline in slightly drier habitat, probably to avoid competition from larger birds. Alongside the Semipalmated Plovers and Western Sandpipers we saw them feeding among, they seemed to mix right in though, often wading up to their downy chests along the edge of the river.

It wasn’t until we returned home and uploaded the photos that the Least’s most interesting characteristic – to me – became evident.

least sandpiper serrated bill

Avian adaptations make for fascinating study in their own right. Questions beginning with “Why,” and “How” immediately pop into one’s mind when examining the unique characteristics birds have evolved to ensure success in their environments, though no degree of explanation can diminish one’s amazement at these adaptations.

From the time when at a young age I first noticed the sharp, undulating teeth on a steak knife, serrations have fascinated me. I can’t resist running the pad of my thumb along the edge of a fossilized Megalodon tooth, and I have spent hours contemplating the fearsome saw-toothed edges of Atlantic Stingray tail spines. Although they no longer possess the dentition of the dinosaurs that preceded them, several species of birds – today’s dinos – have evolved serrated bills. Apparently Least Sandpipers are among those species. Why?

Serrations make sense in dedicated piscivores such as Red-breasted and Common Mergansers, but how are they useful to these little peeps? The serrations don’t seem long enough to serve as filters; perhaps they aid in grasping any of the larger invertebrates that might be encountered as the birds probe beneath rocks and sift through silt.

least sandpiper feeding

This little gal or guy has some sort of tiny morsel in its bill. It can use water tension to transport small items such as this from its bill to its mouth.

The range map, below, indicates that this species might nest in the Chigniks, yet another reason to man the skiff early this coming year and resume exploring.

Least Sandpiper Range Map: with permission from The Cornell Lab of Ornithology, Birds of the World

Least Sandpiper Calidris minutilla
Order: Charadriiformes
Calidris: from Ancient Greek kalidris or skalidris, a term Aristotle used for some gray-colored shorebirds¹
minutilla: Medieval Latin minutilla = very small

Status at Chignik Lake: Common on Chignik River gravel shorelines and bars for a few weeks in summer

David Narver, Birds of the Chignik River Drainage, summers 1960-63: Common

Alaska Peninsula and Becharof National Wildlife Refuge Bird List, 2010:
Common in Spring & Summer; Uncommon in Fall; Not reported in Winter

Aniakchak National Monument and Preserve Bird List: Present