Apparent survival of adult Thayer's and Glaucous Gulls nesting sympatrically in the Canadian high Arctic.

The article provides information on a study which estimated the apparent survival of adult Thayer's Gulls Larus thayeri and adult Glaucous Gulls Larus hyperboreus nesting sympatrically on St. Helena Island, Nunavut. The study, which used five consecutive years of capture-mark-resight data, also assessed the influence of sex, species, year and resighting using the program MARK and compared findings with previously published survival estimates of other gull species. The study noted that there were different patterns in estimates of annual survival in different years and that the mean survival for Thayer's Gulls was low while the survival of Glaucous Gulls was comparable to other white-headed gulls. The findings of the study contribute to the limited demographic information on the polar gulls.