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Why are Killer whales black and white?
Killer whales have a very distinctive pattern of white, black and gray coloration over their entire body. The distinctive patterns are a form of camouflage to hide their presence when in search of food.
Since Killer whales hunt for fish, seals and other large mammals, their very survival hinges on successfully catching prey — which in most cases will be on the alert for predators.
Just as military airplanes are colored light on the undersides and dark on top during wartime — making them less visible from both above and below — so too are the whales.
In the dark undersea world the whale’s white areas also tend to create the illusion of much smaller objects, while the black body virtually disappears in the darkness — allowing the whale to visually appear to be much less of a threat than it actually is.
Illustration courtesy Kelley Balcomb-Bartok/All Rights Reserved
Can you tell male calves from females?
Whale researchers at the Center for Whale Research, based here on San Juan Island, have been documenting the local orca populations since 1976. During the course of this study over 95 whales have been born.
 For researchers, determining the gender of a calf adds a tremendous amount of information to the general understanding of the social structure and health of this local orca population.
To determine the gender of a new calf — or any orca whale — researchers rely on photographs of the underside of a whale when distinguishing a male from a female.
The difference is quite pronounced, if you know what to look for. Male orca whales have an elongated white pattern (above, left) stretching towards the tail in the genital region, while the females’ white patterns are much more rounded (above, right) with mammary slits visible.
Illustration courtesy Kelley Balcomb-Bartok/All Rights Reserved
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