Black terns have two interesting courtship flights. At the end of their aerial display, the male follows the female to a perch and feeds her. Both adults incubate the one to five eggs that are laid, which hatch in 20 to 23 days. The chicks can swim, walk, and run by the time they are two days old. If disturbed, thy can hide in vegetation.
Terns often lay more eggs if the first ones are lost.
On the breeding grounds, black terns are primarily insectivorous, eating damselflies, dragonflies, and mayflies. They also eat small crustaceans, spiders, and small fish. Nova Scotia black terns migrate to the coast, then south to wintering grounds from Panama to Peru and Surinam. In winter, they have white underparts and a grey back. Although black terns now nest in Nova Scotia, it is still a fragile occurrence.