First record of orca predation on franciscana dolphins (Pontoporia blainvillei) in Argentina

ANTONELLA PADULA; JOAQUIN GANA; GISELA V GIARDINO; CAROLINA DE LEON; ANDREA ELISSAMBURU; DIEGO RODRÍGUEZ; PABLO DENUNCIO

THE LATIN AMERICAN JOURNAL OF AQUATIC MAMMALS

SOLAMAC

Año: 2022 vol. 17

1676-7497

The orca, or killer whale (Orcinus orca), is a cosmopolitancetacean species that is known as a predator of a wide rangeof prey, including bony fishes, sharks, sea birds, sea turtles, seaotters, pinnipeds, dolphins, and whales (Jefferson et al., 1991;Visser, 2005; Ford, 2017; Wright et al., 2021).Previous reports of the orca diet off Argentina includebroadnose sevengill sharks (Notorynchus cepedianus) (Reyesand Garcia-Borboroglu, 2004), birds (Copello et al., 2021) andmarine mammals such as dusky (Lagenorhynchus obscurus) andcommon (Delphinus delphis) dolphins (Coscarella et al., 2015),southern right whales (Eubalaena australis) (Sironi et al., 2008),South American sea lions (Otaria flavescens) (López and López,1985; Grandi et al., 2012), and southern elephant seals (Miroungaleonina) (Hoelzel, 1991). However, all these records came fromobservational studies in Patagonia.In northern Argentina, the trophic ecology of orcas is poorlyknown. This may be related to the fact that historically orcasseemed to be sporadic visitors near the coast with only a fewsightings per year, and that stranding events are very infrequent inthis region. However, recent records of sightings suggest that thereis an increasing trend in their occurrence in the area (Biologí