Orcas (Orcinus orca), also known as Killer whales, are easily recognized by their black-and-white markings on their bodies. More specifically, these whales have an iconic white patch near their eyes. But why do these mammals sport the markings?
There are various thoughts as to why orcas have these patterns. Their coloring pattern has multiple uses, from camouflage to coordination as they swim. The patterns also help researchers study genetics within a pod.
Orca's Stealthy Black and White Camouflage
The orca’s black-and-white bodies help them blend in with their surroundings and make them appear smaller. The darker markings shrink their body outlines, and in sunlight underwater, some prey might not recognize the whale as a dangerous predator.
Their black tops and white underbellies are a ‘counter-shaded’ pattern that allows them to blend in with anything looking above the water and from below the surface towards the top. If prey is looking at the orcas from below, they blend in with the brighter ocean surface. This helps them swim the oceans in incognito mode.
Aside from their black-and-white pattern, the whales sport grey splotches called saddle patches near their dorsal fin that scientists use to identify individuals.
Read More: Skin Lesions Spotted on Killer Whales: What Could They Mean?
Orcas Have Unique Eye Patches
The eye patches can serve as a way for the killer whales to read social cues and coordinate hunting and swimming in formation. Similar to their overall body markings, the white patches above their eyes might also serve a camouflaging purpose to confuse prey. This stealthy method allows orcas to approach prey without them realizing it.
Markings along the orcas, such as the eye patch and saddle patch near their dorsal fin, again help researchers identify differences between various populations and individuals within a pod.
Pods of orcas from Norwegian, Icelandic, British, Spanish, and Greenlandic oceans all have varying eye patch shapes, according to a study published in the Journal of the Marine Biological Association of the U.K.
While most orcas have symmetrical eye patches that are aligned straight across their bodies, a few whales from the Scottish islands, the Hebrides, have eye patches that slope at the end and align with their tail instead. The study found that because of this, the specific population of whales has low gene flow since they mostly keep to themselves instead of intermingling with other whale pods.
Even more recently, researchers say that the coloring and shape of the killer whale’s saddle patch differ among subspecies of killer whales. A study published in the Royal Society Open Science found that ‘resident’ and ‘transient’ killer whales were different ecotypes or variations of orca characteristics specific to a region. The orcas can have different body sizes, hunting strategies, color patterns, and social structures.
Read More: Instead of Hunting in Groups, Orcas May be Attacking Great White Sharks Alone
An Orca's Belly Is Distinctively White
Orcas are known as killer whales because of their hunting strategies and because they prey on larger whale species. As extremely intelligent whales, orcas even use the coloring on their bellies to lure in their prey.
To herd fish near the water’s surface, the whales use a herding strategy called the carousel method. Orcas will swim close to a school of fish and flash their white bellies toward them until they are positioned where the orcas want. Then, the orcas will smack their tails on the edge of the school of fish and eat any stunned fish.
Orcas are not the only animals that have markings and are counter-shaded. Penguins, for example, also have a tuxedo pattern that helps shield them from prey. Other animals that are not aquatic use counter-shading patterns to hide from prey and predators. These include caterpillars, moths, some frogs, and even squirrels.
Read More: Orcas May Devour Marine Mammals, But They Typically Avoid Harming Humans
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Sea World. All About Killer Whales: Physical Characteristics
NOAA Fisheries. Killer Whale
Journal of the Marine Biological Association of the UK. A comparison of pigmentation features among North Atlantic killer whale (Orcinus orca) populations
Royal Society Open Science. Revised taxonomy of eastern North Pacific killer whales (Orcinus orca): Bigg’s and resident ecotypes deserve species status
Canadian Journal of Zoology. Surface and underwater observations of cooperatively feeding killer whales in northern Norway
Encyclopedia of Evolutionary Psychological Science. Countershading
