Comments: Marine; open ocean, often near edge of continental shelf; also seas, gulfs, bays, and estuaries. Mainly pelagic, seldom approaching land except for nesting (Eckert 1992). Concentrates in summer in waters mostly 20-40 m deep near Cape Canaveral, Florida. Dives almost continuously, to depths of up to at least several thousand meters; may linger at the surface at midday but spends most of time submerged.
Nests on sloping sandy beaches backed up by vegetation, often near deep water and rough seas. Largest colonies use continental, rather than insular, beaches (CSTC 1990). Absence of a fringing reef appears to be important. Deposits eggs in moist sand. Individuals sometimes change to different nesting beach between nestings during a single year; changed to sites 30-110 km away in West Indies (Eckert et al. 1989; see also Keinath and Musick 1993). May rapidly occupy newly formed nesting habitat (Pritchard 1992).