As a pod, killer whales “wave-washed” seals

Killer whales (Orcinus orca) are fast swimming, intelligent, social animals and the largest apex predators in the ocean. They hunt in packs/pods using various tactics.

Pitman & Durban (2011) report that there are three species of killer whales found in Antarctica. I will be introducing the hunting behaviour and prey selectivity of the ‘Type B’ or ‘pack ice (PI) killer whales’, which are seal specialists. PI killer whales are found not just exclusively preying on a species of seals but also employing tactics during their hunts. Moreover, the species is the only marine mammal known to regularly detect and capture prey out of the water.

When these whales are hunting in pack ice, they first locate seals on ice floes by “spy-hopping”, a technique of lifting their heads vertically out of the water to check the situation above the surface. When one detects a seal on the ice, its response depends on the species of the seal (Pitman & Durban, 2011).

Crabeater and leopard seals are usually left alone due to their aggressiveness. On the rare occasions that these two species are attacked, it appears that uncertainty over the species or misidentification has occurred. Those seals are then left unharmed. If it is a Weddell seal (Leptonychotes weddellii), the whale will surface with the rest of the pod. After spy-hopping together around the edge of the floe, they will initiate a “wave-wash” attack (Visser et al, 2008; Pitman & Durban, 2011).

“Wave-washing” refers to the technique adopted by a pod of PI killer whales which approaches an ice floe in a parallel formation while beating their flukes in a fast and sychronised pattern to create waves. For a small floe, the whales will create a wave to break over it and wash the seal into the water while for a larger floe; the whales will create a smaller wave to break it into smaller pieces. These attacks are highly successful even though there are instances where seals escaped.

Watch this video for a better understanding of the “wave-wash” technique.

A killer whale “spy-hopping” a Weddell seal

Source: Southwest Fisheries Science Center, NOAA Fisheries Service

Photo: Robert Pitman




A pod of killer whales preparing to “wave wash” a Weddell seal

Source: Southwest Fisheries Science Center, NOAA Fisheries Service

Photo: John Durban




Literature cited:

“Killer Whales and Weddell Seal” by John Durban. Southwest Fisheries Science Center. URL: (accessed on 6 April 2013)

“Killer Whales “Wave Wash” Seal | Frozen Planet” by Discovery Networks. Discovery Channel, 16 March 2012. URL: (accessed 6 April 2013).

“Pack ice (Antarctic type B) killer whales inspect Weddell seals prior to wave-wash attacks” by Robert Pitman. Southwest Fisheries Science Center. URL: (accessed on 6 April 2013)

Pitman, R. L. & Durban, J. W., 2011. Cooperative hunting behavior, prey selectivity and prey handling by  pack ice killer whales(Orcinus orca), type B, in Antarctic Peninsula waters. Marine Mammal  Science, 28(1): 16 – 36.

Visser, I. N., Smith, T. G., Bullock, I. D., Green, G. D., Carlsson, O. G. L. & Imberti, S., 2008. Antarctic peninsula killer whales (Orcinus orca) hunt seals and a penguin on floating ice. Marine Mammal Science, 24(1): 225 – 234.