Behavioural differences between breeding and non-breeding populations of Storm Petrels Hydrobates pelagicus

Storm Petrels caught using a sound lure at a non-breeding site produced nearly equal numbers of controls (individuals previously ringed elsewhere) and recoveries of birds found again elsewhere after ringing. In contrast Storm Petrels caught at a breeding colony showed a ratio of 9:1 between controls and recoveries. Ringing of the non-breeding population produced a between-year recapture rate of only 3.1%, whereas between-year recaptures at a breeding colony amounted to nearly 10%.