Sperm whales inhabit all oceans of the world, and have been observed in Oregon waters from March through November. Sperm whales are usually found in deep off-shore waters so they are only occasionally seen off Oregon by fishers and birders on offshore trips.

It is the largest of the toothed whales and possesses the largest brain of any animal with an enormous head to house it. Sperm whales have 20 to 26 large conical teeth found only in their lower jaw. A mature male can grow to 52 feet long with its head representing up to one-third of its length. It is also the largest living toothed animal, feeding on giant squid, sharks, rays and fishes. Plunging to 9,800 feet for prey, it is the deepest diving mammal. Its clicking vocalization, a form of sonar, is the loudest sound produced by any animal.

The blow is a noisy, single stream that rises up to seven feet or more above the surface and points forward at a 45-degree angle since the blocky head is asymmetrical and the blow hole is located on the left side near the tip. The sperm whale's flukes are triangular and very thick. The whale lifts its flukes high out of the water as it begins a feeding dive. It has a series of ridges on the back's caudal third instead of a dorsal fin. The largest ridge was called the 'hump' by whalers, and can be mistaken for a dorsal fin because of its shape and size. In contrast to the smooth skin of most large whales, a sperm whale’s black skin is wrinkly like a prune.

Sperm whales were a prized catch for whalers in the 1800s for the rich waxy substance found in their heads called spermaceti. Spermaceti was used to make smokeless candles, soap, cosmetics and lamp fuel. In the mid-1800s, it is estimated that whalers killed perhaps 5,000 sperm whales each year.

Photo by Amila Tennakoon, Flickr