How do sandpipers use their bills to find food in mud?

Sandpipers, which belong to the family Scolopacidae, utilize their slender bills in two primary ways to forage in mud:

• Surface Feeding: They use their bills as forceps to pick up invertebrates found on the surface of the mud.1
• Probing: Especially in the case of calidridine sandpipers, they use their bills to probe into the mud to locate prey.1

These birds are highly specialized for this behavior. Their bills are typically slender and flexible, with a mobile tip that contains a concentration of tactile sense organs under the horny covering of the beak (the rhamphotheca). This adaptation allows them to detect prey underground. Once the prey is located, the tip of the upper jaw—controlled by specific jaw muscles—is used to grasp worms or larvae and inch them along the bill toward the throat for swallowing.2