Prospecting is an important behaviour in juveniles and failed breeders, and it serves as the basis for informed decisions about future breeding attempts. Actively breeding adults are not considered to prospect, as this behaviour is time and energy costly. Seabirds are in general highly philopatric, which decreases the need for prospecting in successfully breeding birds. However, tracking studies have provided the evidence that actively breeding seabirds do visit conspecific colonies during incubation and chick-rearing. In Croatia, actively breeding Common Terns were prospecting colonies at distances of 9-27 km, and Auduoin’s Gulls were prospecting at distances up to 194 km; in both species, prospected colonies were outside of their foraging range. Birds of both sexes were prospectors, and some prospecting trips included overnight stays at the visited colony. Studied populations of both species showed inter-annual changes of breeding patches and breeding losses caused by predation or flooding. Meta-analysis of 31 populations of 14 gull and tern species confirmed prospecting in 85.7% of studied species and showed that prospecting of active breeders is more common in populations with frequent inter-annual changes of breeding patches and among females. Tracking studies designed for different purposes might nevertheless be a good source of information about prospecting behaviour. However, to identify factors affecting patterns of prospecting of adult birds in different environments, more longterm tracking studies with simultaneous monitoring of breeding success are needed.