Nonetheless, it cannot be ruled out that reduced areal coverage of the bay during winter may have contributed to reduced encounter rates of Bryde’s whales during this period. It is, however, unlikely that this could explain the smaller aggregation sizes encountered during this period and the lower incidence of multispecies associations and feeding events, relative to other times of the year. Aggregation size of Bryde’s whales was positively correlated with the occurrence of feeding behaviour in this study. This was similar to the situation in the Gulf of California, where solitary individuals were usually travelling, whereas aggregations of comparable sizes to those found in this study during summer and autumn were associated with feeding . During winter there are increased sightings of Bryde’s whales farther north along the East Coast, frequently in groups with common dolphins and Cape gannets . This appears to coincide with the annual north-eastward migration of sardine into KwaZulu-Natal waters . Thus, movements of animals away from the study area in pursuit of prey during the sardine run could have contributed to the observed temporal differences in encounter rates, aggregation size, interspecific interactions, and feeding behaviour of Bryde’s whales in our study.