It flies over water with fast, jerky wingbeats and a distinctive hunchback appearance, with the bill pointing slightly downward.

Threats include egg and fledgling predators, high tides and recreational use of nesting beaches.

While numbers have gradually increased with its protected status, it is still vulnerable to predators, natural disasters or further disturbance by humans.

Recent threats include the gull-billed tern (Sterna nilotica), which can decrease reproductive success in a colony to less than 10%.

The breeding colonies are not dense and may appear along either marine or estuarine shores, or on sandbar islands in large rivers, or in areas free from humans or predators.

Courtship typically takes place removed from the nesting colony site, usually on an exposed tidal flat or beach.

[9] In the San Francisco Bay region, breeding typically takes place on abandoned salt flats.

Where the surface is hard, this species may use an artificial indentation (such as a deep dried footprint) to form the nest basin.

After young chicks are three days old, they are brooded less frequently by parents and require wind blocks and shade, and protection from predators.

Notable disruption of colonies can occur from predation by burrowing owls, gull-billed terns and American kestrels.

[15] Predation on inland breeding terns by coyotes, bobcats, feral dogs and cats, great blue herons, Mississippi kites, and owls has also been documented.