Natural Barrier Feeding Technique in Megaptera novaeangliae in Central Coastal Area of Golfo San Jorge, Patagonia, Argentina

RIERA, MARINA GRISELDA; LUCCHETTI, DANIEL; COSCARELLA, MARIANO A.

AQUATIC MAMMALS

European Association for Aquatic Mammals

Año: 2022 vol. 48 p. 126 - 131

0167-5427

Humpback whales display a wide variety of feeding techniques depending on the site, prey species, and prey density. At least eight feeding behaviours have been described for different populations around the world. At Punta Marqués, in Golfo San Jorge, humpbacks are using a previously undescribed feeding technique, named natural barrier feeding, consisting of the whale forcing prey against a barrier (a wave-cut platform) and then accelerating towards the prey using, generally, a lateral lunge-feeding approach to capture small fishes. Usually, the feeding events take place at a very close range from the coast (between 3 and 20 m away) in shallow waters (3 to 5 m depth). Using drone footage they were able to understand the behavioural sequence. The authors recorded more than one individual performing the new behaviour and over the course of the coming years they will keep monitoring the area to study if other individuals within the population learn how to use this technique, a process that can occur through social or asocial learning.. An increasing number of humpback whales have been recorded in the area ,and these observations lead the authors to hypothesize that at least some humpback whales use the coastal waters off Patagonia for migration?for example, when they travel from their breeding area in Southern Brazil to their feeding location off South Georgia and the South Sandwich Islands. Local entrepreneurs are interested in developing a new whale-watching area based on recurrent sightings; and if humpback whales are using this area as a feeding stop during their migration, a call for management actions is in place, mainly because there is no enforcement of the restrictions for recreational navigation in this area.