False Killer Whales and Bottlenose Dolphins Form Anti-Predator Partnership

False killer whales, as their name suggests, share a lot of similarities with true orcas, but the creatures remain one of the most understudied cetaceans. Now, new research on the mysterious mammals suggests that a group of them off the coast of New Zealand has formed a relationship with a group of bottlenose dolphins to keep predators at bay.

A research team from Massey University in New Zealand spent the past 17 years studying a group of 61 individual false killer whales (Pseudorca crassidens) in a region of ocean off the nation's coast.

So many years of observation led the researchers to find that 88 percent of the identified individuals were part of the same social network and were re-sighted in the same area over several years.

This group of false killer whales were also shown to associate with bottlenose dolphins (Tursiops truncates) in a coordinated anti-predatory effort that in some cases lasted more than five years and at ranges of up to 650 kilometers.

"The anti-predatory function of mixed species associations is mostly achieved through a greater chance of detecting a predator through more eyes watching out," said Jochen Zaeschmar, from Massey University. "However, it is hard to say if this is mutualistic or parasitic, that is whether the two species actually co-operate or whether one just opportunistically exploits the detection ability of the other. Lastly, as both species are highly social, sociality may also play a role."

Just like true orcas, false killer whales will attack and kill other cetaceans, but the two species do not belong to the same genus. Their physical appearance is also dissimilar. False killer whales lack the prominent white spot above their eyes, they grow up to 20 feet long and weigh up to two tons. They have round, tapered snouts that overhangs the jaw.

In rare cases, bottlenose dolphins and a false killer whale have bred, producing an offspring referred to as a "wholphin."

Zaeschmar said more research on this close-knit population of false killer whales is warranted.

The most well-studies false killer whale populations are off the coast of Hawaii, where three distinct pods have been documented.