A preliminary comparison of population estimation by tape response and mark/recapture methods for Storm Petrels Hydrobates pelagicus in two contrasting Scottish colonies

The tape response method of population estimation was compared to mark/recapture methods for Storm Petrels Hydrobates pelagicus on two Scottish islands. On Priest Island the du Feu single‐session mark/recapture method gave an estimate not significantly different from the tape response method and was less demanding on personnel. On Eilean Hoan the Jolly‐Seber estimates made in 1998 and 1999 were similar to that obtained from the tape response method in 2001. Jolly‐Seber estimates made in 2000 and 2001 were similar to the du Feu estimate made in 2001, but different from the tape response method. The overall annual survival estimate of 0.87 on Eilean Hoan was identical to the previously published figure and almost the same as the 0.86 calculated from national ringing returns. These initial findings are used to identify problems with the mark/recapture methods and to suggest ways of solving them.