At the mention of sandpipers, many birders mentally
groan. After all, sandpipers are those
dull, brownish little creatures that skitter over mud and all look alike. In other words, it can be really hard to
appreciate them. But actually, on closer
study, sandpipers are unusual and highly fascinating birds. And, no, they don’t all look alike! I will focus on two very distinctive, common
sandpipers that can be seen in migration now: the Solitary Sandpiper and the
Spotted Sandpiper.
Although they are not closely related, the Solitary
Sandpiper (Tringa solitaria) and the Spotted Sandpiper (Actitis macularius) are
often seen together feeding in the same ponds and lakes, frequently those with
woods or at least low-lying vegetation nearby.
Both can be found migrating in Mississippi from about March to June in
the spring, and late July to late October in the fall. The Spotted Sandpiper is an occasional winter
resident in the state, as well, but is more common along the coast than inland.
Both sandpipers forage and migrate singly or in small
groups, and both exhibit tail-bobbing behavior.
With the Spotted, the entire body is teetered; the bird is in constant,
jittery motion: scampering along the water’s edge, picking up small insects,
mollusks, crustaceans, and even tiny fish.
The Solitary Sandpiper has slower, more deliberate movements, and when
it pauses, it often bobs its head and tail.
It has longer legs and a longer bill than the Spotted, which enables it
to feed in slightly deeper water, where I assume the menu would include bigger
fish and frogs! As an additional feeding
adaptation, it often shakes its foot above the water to draw small fish and
insects to the surface.
If you come unexpectedly upon either of these sandpipers, they
will probably fly up immediately, uttering high-pitched peet-WEET calls (the
Solitary’s call is the higher pitched of the two). Fortunately, their flight styles are very
different and distinctive. The Solitary
Sandpiper has graceful, swallow-like wingbeats and displays long, pointed wings
and white edges on its tail. Spotted
Sandpipers fly close to the water and give fluttery, shallow beats of their
shorter, more-rounded wings, each of which shows a thin, white stripe.
Once the sandpipers land on the bank and begin feeding
again, their colors and patterning are apparent. The Solitary Sandpiper is slightly larger
than the Spotted, with a longer neck and body, and it has a wide, white
eye-ring that gives it an alert look.
Its head, neck, and breast are finely streaked with brown, its belly is
white, and its back is dark brown and shiny, with a dusting of tiny white
spots. The thin, dark bill and dark,
greenish-gray legs complete the picture.
The Spotted Sandpiper is relatively small and stocky, with orange legs
and bill, brown upperparts, a white eyebrow and slight eye-ring, and in the
breeding season a boldly spotted breast and belly. At least before the birds molt in the fall
and replace the spotted front with plain white, you can sometimes tell the
sexes apart. Females have larger spots
that extend farther onto the belly than males.
But why would the female bird be more distinctively
marked? The answer lies in the Spotted
Sandpiper’s breeding biology. Along with
phalaropes, it is unusual in that the females are polyandrous, mating with more
than one male—sometimes up to five! Each
time after mating, the female lays a clutch of up to four brownish eggs, which
the male is solely responsible for incubating.
However, the female does help with constructing the nest—a shallow
scrape in the ground, lined with grass.
After the eggs hatch, the male alone raises the chicks, which are born
precocial like all sandpipers.
While the Solitary Sandpiper is monogamous and doesn’t
exhibit such unusual breeding behavior as the Spotted, it is unique among North
American shorebirds in that it nests in trees.
A female Solitary Sandpiper will add a little extra nesting material to
the abandoned nest of a songbird, such as a Rusty Blackbird, American Robin, or
Cedar Waxwing, incubate her four well-camouflaged, brownish eggs, and care for
the young with her mate. Tree-nesting is
so unusual among shorebirds (the Green Sandpiper of Eurasia is the only other
species known to do it regularly) that, for decades, no one was sure where the
Solitary Sandpiper nested until 1903, when the secret was finally discovered.
Spotted Sandpipers are one of the most widespread
shorebirds, commonly found over much of North America, although they aren’t
known to breed in Mississippi and some other southern states. Solitary Sandpipers are more restricted in
range, occurring in the breeding season mainly in Canada and Alaska.
The numbers of both of these sandpipers appear to be fairly
stable, and that’s good news. With care
and protection, generations years into the future will be able to observe the
fascinating behaviors of these and other birds that have been living here for
eons. A world without the little brown
sandpipers that enliven our fields, woods, and wetlands would be bleak.
