Scientists are baffled by a recent phenomenon occuring in the oceans around the world, particularly in North Pacific Oceans. Humpback whales have been observed working in pairs to save various prey of orca whales including, sea lions, harbor seals, and grey whales. Is this an altruisitic behavior or is something deeper happening? Could the humpbacks have complex emotional processes such as what is seen in primates causing them to act with sentimental instinct? Then we must also consider the fact that humpback calves themselves are prey to the orca whale, and the Humpacks’ are acting under some internal instinctual parental behavior.
The number of recorded incidents of humpback whale interference with orca predation was recorded in a recent article by Robert L. Pitman published in July 2016. There was a documented 115 interactions between orcas and humpbacks collected between 1951-2012 . Overall in the 115 interactions 95% of them were with killer whales (orcas) attacking mammalian species. Of the mammalian species orcas attacked 95% of the cases were also prey to the humpback whales. Humpback could be exhibiting scavenging behavior, similar to interactions between hyennas and lions.The humpback’s could simply be trying to “catch a meal”, but the theory of altruism was introduced due to a radical behavior logged in the report of Pitman’s study.
In some instances, the study described a humpback whale putting a sea lion on its belly and using its flipper to keep them on their body until the pair reach a new icebarge for the sea lion to escape. Why would the whale bring them to safety if they wanted to catch a meal? The prey is now safetly on land away from their origional orca predator. Investigation of this interaction indicates that prey could not reciprocate any form of fitness to the humpback whales. So, this may be altruism or the whales must be gaining some kind of benefit from disrupting the foraging of orcas from another source.
The humpback whales could be displaying these actions in the evolution of parental care. Orca’s have been known to attack humpback whale calves for feeding upon. If the humpbacks prevent orcas from eating they could become weak and unable to attack their young. It could also cause the orcas to change feeding grounds, so the likelihood of an attack on a infant would decrease. The downfall to this theory of parental care is that orca whales only prey on humpback calves 11 percent of the time, and raises the question if that is sufficient reason to expose oneself to the costs of fighting an orca herd.
The complexity of animal behavior produces numerous hypothesis to why the humpback whales are displaying this response to orca attacks. Research is presently being conducted to explore the reasoning behind this behavior. Until further research is published the questions remains; is this altruism, parental care, territorialism, emotionally based, or a combination of these processes?