The beach thick-knee is usually seen alone or in pairs, although it occasionally occurs in small groups (3) (4). It normally hunts at night or at dawn and dusk, slowly stalking its prey or making rapid lunges at it (2) (3) (4), and sometimes probing its beak into mud, sand or short grass (2). The beach thick-knee mostly forages among rocks, on intertidal areas of beaches and estuaries, or among mangroves (2) (4) (5). If disturbed, it often flies out to sea (2), moving with slow, heavy wing beats (3).
The diet of the beach thick-knee consists predominantly of crabs, as well as other marine crustaceans (2) (3) (4) (5) (8). This species uses its massive beak to hammer open its prey (2) (5), and it sometimes washes its food before swallowing it (5).
The beach thick-knee is thought to be monogamous (2), and it breeds in isolated pairs either at the back of a large beach, or among mangroves, grass, on sandbanks or on islands (2) (4) (5). Pairs may nest in the same area for several years (2) (8). The breeding season generally runs from September to November in temperate parts of Australia (2) (5), but further north the beach thick-knee may breed between July and November (2).
The beach thick-knee’s nest consists of a shallow scrape in the ground (2) (4) and is not lined, although it may be surrounded by a ring of twigs and dead leaves (2). Only one egg is laid, but the female beach thick-knee may lay another if the first is lost. The egg is incubated for about 30 days. Both the adults help care for the young, which is able to fly at about 12 weeks old, but does not become independent until it is 7 to 12 months old (2) (4) (5). The eggs of the beach thick-knee are vulnerable to predators such as cats, dogs and birds of prey, and may also be lost in high tides (2).