Habitat use by southern right whales, Eubalaena australis (Desmoulins, 1822), in their main northernmost calving area in the western South Atlantic

摘要

The subtropical and temperate coastal waters of the western South Atlantic are an important calving ground for southern right whales, Eubalaena australis. From 2002 to 2008, data on right whale distribution and habitat characteristics were collected in 14 bays along the coastline of Santa Catarina State, Brazil. Generalized linear models with a negative binomial error distribution were used to determine which environmental (beach morphotype, bay mouth width, bay inclination angle, north-south and east-west wind components), and temporal (month and year) variables best explained the aggregation pattern of individuals. Our results suggested that both cow-calf pairs and adults unaccompanied by calves prefer bays with dissipative beaches, and that cow-calf pairs apparently avoid bays facing southeast during days of strong east-west winds. The number of sightings peaked in September and tended to increase over the study period. One particular embayment (Ribanceira beach) had considerably higher numbers of animals and may be considered a preferred spot in this calving ground. Our findings contribute to a better understanding of the species' habitat use and ecological requirements and should be taken into account if new management measures are implemented to further increase protection of southern right whales in the region.