Population size and residency patterns of northern bottlenose whales (Hyperoodon ampullatus) using the Gully, Nova Scotia

A population of northern bottlenose whales (Hyperoodon ampullatus) uses the Gully, a submarine canyon off coast Nova Scotia, Canada. Eleven years photo-identification records has permitted estimation size using mark-recapture techniques. The estimate was small (133 individuals, 95% CI = 111-166 from left side identifications; 127 106-160 right identifications). not closed, with combined mortality, mark change and emigration rate estimated at 13% per year for identifications (95% 9-17) 14% 10-18). There no significant increase or decrease in between 1988-1999 (change size: side: –0.13% year, -3.4 to 3.9; –0.43% -4.5 3.1). sex ratio roughly 1:1, equal numbers sub-adult mature males. Over summer field season, individuals emigrated from, re-immigrated into spending an average 20 days within Gully before leaving (left 19 days, SE 17; 23 10). Approximately 34% present any time. Individuals all age classes displayed similar residency patterns although there were annual differences as spent less time 1996 than 1990 1997. Sighting rates extensive fieldwork, indicating little variability number each summer. Accurate estimates will be useful determining regulations required coverage marine protected area Gully.