When you’re at the beach and you see a small, long-legged bird running along the beach, how confident are you that it is a sandpiper? Or is it a sanderling? What’s the difference, anyway?
There are several types of sandpipers, including snipes, dunlins, woodcocks, curlews, and sanderlings. When you can differentiate between these little beach birds, you can enjoy your oceanside birding even more.
What is a Sandpiper?
A sandpiper is a type of shorebird. All sandpipers are part of the Scolopacidae family in the order Charadriiformes, but not all sandpipers have “sandpiper” in their name.
Sandpipers have several traits in common, including:
- Size (about 6-12 inches long)
- Long legs and bills
- Short tails
- Narrow wings
- Mostly brown, cream, and black in color
- Habitat (beaches and mudflats along both ocean coastlines and inland wetlands)
- Diet (insects, crustaceans, and worms)
- Vocalizations (a piping sound)
The Spotted Sandpiper is the most abundant sandpiper in North America, and the Common Sandpiper is the most abundant in South America.
Although sandpipers can be difficult to distinguish from one another, the spotted belly and chest of the Spotted Sandpiper make it easier to identify than some of its close relatives.
Types of Sandpipers
There are 98 types of sandpipers in the world. 22 of those sandpipers can be found in North America.
Those 22 sandpipers are: Bairds, Broad-billed, Buff-breasted, Common, Curlew, Green, Least, Marsh, Pectoral, Purple, Rock, Semipalmated, Sharp-tailed, Solitary, Spoon-billed, Spotted, Stilt, Terek, Upland, Western, White-rumped, and Wood.
What is a Sanderling Sandpiper?
Sanderling Sandpipers are part of the Calidris genus. They are small and plump, and their bill is a bit thicker than most other sandpiper bills.
Sanderlings fit right into the middle of the pack when it comes to sandpiper size; the largest sandpipers in the world are Far Eastern Curlews, and the smallest sandpipers are called Least Sandpipers.
Both sexes have the same measurements:
- Length: 7.1-7.9 in (18-20 cm)
- Weight: 1.4-3.5 oz (40-100 g)
- Wingspan: 13.8 in (35 cm)
Identifying a Sanderling
Sanderlings only breed along the northern tundra and along the Arctic Circle of Canada. That means that they are rarely seen sporting their summer plumage, which is quite dramatic.
They are black, white, and rufous colored with black bills and legs. Their wings are dark with white stripes.
During the rest of the year, their coloring is much paler. From above, they are light gray, and from below, they are white. They have a grayish-black mark on their shoulder.
The Sanderling’s bill is about the same length as its head.
Sanderling Habitat
Sanderlings prefer ocean shorelines, but they will also inhabit mudflats. Their range is nearly entirely coastal, although they can be spotted throughout much of North America during their migration window.
They are familiar sights on coastal beaches around the world, including the Atlantic, Pacific, and Gulf Coasts of North America.
Diet of a Sanderling
Sanderlings are incredibly active birds. They are usually far more active than other pipers on the beach, and most of their activity is a result of their hunting behaviors.
Sanderlings eat sand crabs and invertebrates, including amphipods, isopods, insects, worms, and mollusks.
They have also been known to eat carrion and food scraps left behind on beaches by humans. One of their favorite springtime foods is horseshoe crab eggs.
During the breeding season, when they are in the Arctic tundra, their diet consists of flies, insects, seeds, leaves, and beach algae.
How is a Sanderling Different from a Semipalmated Sandpiper?
if there is one bird most likely to be mixed up with a Sanderling, it’s the Semipalmated Sandpiper. These two pipers have very similar appearances, and being able to distinguish one from the other takes practice!
A collaboration between the Delaware Shore Bird Project, the Delaware Museum of Natural History, the Delaware Division of Fish and Wildlife, and the US Fish and Wildlife Service has led to a useful guide for being able to tell the difference between these two common North American shorebirds.
The key takeaways from the guide are as follows:
- Both Semipalmated Sandpipers and Sanderlings often flock together and are seen in large groups at the beach.
- Sanderlings are larger than Semipalmated Sandpipers.
- Sanderlings are also plumper, with a rounder, chunky shape. Their heads are also larger, and they have thicker bills.
- The Sanderling’s face pattern is less dramatic than the Semipalmated Sandpiper’s face.
- Semipalmated Sandpipers have four toes instead of three (this is pretty difficult to spot from a distance, but if you have a picture of the birds, you can use this to help identify them!). Their name is derived from the fact that their toes are webbed; “palmated” means webbed.
At first glance, you are likely to see a group of sandpipers and assume they are all the same species. Upon closer inspection, you can learn to spot the subtle differences between them.
Once you can tell Sanderlings and Semipalmated Sandpipers apart, you can start identifying other shorebirds, too!
Semipalmated Sandpiper Range
Although Sanderlings are scattered here and there throughout the US during their migration, the Semipalmated Sandpiper is far more widespread as it migrates.
They also have a much broader breeding range across the entire northern tundra, rather than just the central islands of Canada’s tundra.
They are long-distance migrants, too. Ornithologists believe that some individual Semipalmated Sandpipers will fly all the way from New England to South America without a single stop for rest. That’s over 2,500 miles!
They are able to do this because of the fat reserves that they build up before they migrate.
Other Birds That May Get Mixed Up With Sanderlings
Sanderlings are easy to mix up with more than just the Semipalmated Sandpiper. They are sometimes confused with Least Sandpipers, Western Sandpipers, White-rumped Sandpipers, Red Knots, Dunlins, Snowy Plovers, and Piping Plovers.
With practice, you can see the differences between Sanderlings and these birds, too.
A Few More Fascinating Facts About Sanderlings
The Cornell Lab of Ornithology reports a few more fascinating details about Sanderling Sandpipers!
For example, they are usually monogamous, but females sometimes take multiple mates during a breeding season. Perhaps this is an evolutionary strategy to increase their chances of reproductive success.
Sanderlings don’t necessarily migrate. If they are non-breeding, they don’t seem to have an impulse to go north to their breeding grounds, likely because of the extreme energy use. South America has more long-term, year-round non-breeding Sanderlings than North America.
You may find the remains of Sanderling’s mealtimes on the beach, as they are prone to regurgitating pellets – a similar behavior to owls! These pellets will be full of mollusk and shell fragments.
Finally, the Cornell Lab says that Sanderlings will fly in a tight flock when threatened by a bird of prey like a Peregrine Falcon.
You can sometimes spot a falcon by paying attention to a group of Sanderlings (or other shorebirds) that has suddenly taken off altogether in one very tightly grouped flock.