Site fidelity and along-shore range in Hector's dolphin, an endangered marine dolphin from New Zealand

Abstract

To document site fidelity and the alongshore range of individual Hector's dolphins we analysed sightings of 32 photographically identified dolphins, each seen ⩾10 times at Banks Peninsula, New Zealand, between 1985 and 1997. The furthest two sightings of an individual were 106 km apart. All other individuals ranged over less than 60 km ( x̄=31.0 km, SE=2.43) of coastline. Gender did not significantly influence alongshore range (female x̄=30.4 km, SE =3.21, n=18; male x̄=27.4 km, SE=5.68, n=5). Site fidelity was high: for example, on average, individuals were seen in Akaroa Harbour for about two thirds of the years they were known to be alive. These data suggest that impacts on Hector's dolphins are most appropriately managed on a small spatial scale.