Encounters of Thalasseus maximus (Royal Terns) (n = 1387) banded as chicks in South Carolina were used to expand our knowledge regarding winter and migration sites of immature and mature birds, to identify causes of mortality, and to examine natal-site fidelity. Ages of encountered terns ranged from zero (less than one year old) to 27 years old. Mortality was highest in the first year of life. The majority of the encounters (64%, n = 879) were in Florida. Banded birds were also observed outside the US as far west as the Gulf coast of Mexico, east to Guyana, and south to Peru. Royal Terns appear to delay their first migration from winter grounds to breeding sites until the fourth summer. The vast majority of encounters (92%, n = 1275) were due to mortalities; the remaining 8% (n = 112) were of live terns encountered by resighting or capturing. In total, 35% (n = 485) of live or dead encounters were directly attributed to human activities, including entanglement in fishing gear (recorded as late as 1991) and shooting (recorded as late as 1980).