How to identify the Sanderling

To correctly identify the Sanderling (Calidris alba), check each of these features. Birds can be tricky: habit, habitat, and call often confirm a sighting that a single photo cannot.

Size at a glance

Length

18-21 cm (7.1-8.3 in)

Wingspan

35-40 cm (13.8-15.7 in)

Weight

40-100 g (1.4-3.5 oz)

Physical features to check

1. 1

   Plumage

   Overall feather coloration and pattern.

   Non-breeding (winter) plumage is very pale, almost entirely white underneath with a pale grey back and dark shoulder patch (carpal bar). Breeding plumage features rufous (reddish-brown) on the head, neck, and breast, with dark mottling on the back. The belly remains white.

2. 2

   Beak shape

   Shape and color of the bill: a key field mark.

   Relatively short, straight, and stout black bill.

3. 3

   Eye color

   Iris color and any distinctive eye markings.

   Dark brown.

4. 4

   Leg color

   Leg and foot color.

   Black legs and feet. Notably, Sanderlings lack a hind toe, which is unique among most shorebirds and aids in their rapid movement on sand.

5. 5

   Distinguishing features

   Standout features that separate this species.

   Its pale, 'bleached-out' appearance in winter, prominent dark carpal bar, and characteristic 'wave-chasing' behavior are key. The lack of a hind toe is a unique anatomical feature, though not easily observed in the field.

6. 6

   Juvenile appearance

   How young birds differ from adults.

   Juveniles resemble non-breeding adults but have a more scaly or checkered pattern on their back due to dark feather centers with pale fringes. They also show a more distinct dark carpal bar.

7. 7

   Seasonal changes

   Plumage variation between breeding and non-breeding seasons.

   Dramatic change from the pale grey and white non-breeding plumage to the rufous and mottled breeding plumage. The rufous coloration is most intense on the head, neck, and upper breast during the breeding season.

8. 8

   Sexual dimorphism

   How males and females differ.

   Males and females are generally similar in appearance, though females may be slightly larger and have less extensive rufous coloration in breeding plumage.

Key field marks

• Plumage (Non-breeding). Look for a very pale, almost white bird with a pale grey back and a distinct dark patch on the bend of the wing (carpal bar). The underparts are pure white.
• Plumage (Breeding). Observe the reddish-brown (rufous) coloration on the head, neck, and breast, with dark mottling on the back. The belly remains white.
• Behavior. Watch for its characteristic 'wave-chasing' behavior, running rapidly along the water's edge on sandy beaches, probing for food.
• Size and Shape. A small, plump sandpiper with a relatively short, stout black bill and black legs. It appears 'neckless' and compact.
• Flight. Note its swift, direct flight, often in tight, synchronized flocks, especially during migration.

Explore the Sanderling