Where Whales Have Hair and How It's Used

Whales are mammals, and one of the characteristics common to all mammals is the presence of hair. We all know that whales aren't furry creatures, so where do whales have hair?

Whales Do Have Hair

While it's not immediately obvious, whales do have hair. There are over 80 species of whales, and hair is only visible in some of these species. In some adult whales, you can't see hair at all, as some species only have hair when they are fetuses in the womb.

Where Is Hair in Whales?

First, let's look at baleen whales. Most of the baleen whales have hair follicles if not visible hair. The location of the hair follicles is similar to the whiskers in terrestrial mammals. They are found along the jawline on the upper and lower jaw, on the chin, along the midline on top of the head, and sometimes along the blowhole. Baleen whales known to have hair follicles as adults include humpback, fin, sei, right, and bowhead whales. Depending on the species, the whale may have 30 to 100 hairs, and there are usually more on the upper jaw than the lower jaw. 

Of these species, the hair follicles are probably most visible in the humpback whale, which has golf ball-sized bumps on its head, called tubercles, which house the hairs. Within each of these bumps, called tubercles, there is a hair follicle.

The toothed whales, or odontocetes, are a different story. Most of these whales lose their hair shortly after birth. Before they're born, they have some hairs on the sides of their rostrum or snout. One species, though, has visible hairs as an adult. This is the Amazon river dolphin or boto, which has stiff hairs on its beak. These hairs are thought to add to the boto's ability to find food on muddy lake and river bottoms. If you want to get technical, this whale doesn't quite count as marine life, as it lives in fresh water.

Hairlike Baleen

Baleen whales also have hairlike structures in their mouth called baleen, which is made of keratin, a protein that is also found in hair and nails.

How Is the Hair Used?

Whales have blubber to keep them warm, so they don't need fur coats. Having hairless bodies also helps whales release heat more easily into the water when they need to. So, why do they need hair?

Scientists have several theories on the purpose of the hair. Since there are lots of nerves in and around the hair follicles, they are likely used to sense something. What that is, we don't know. Perhaps they can use them to sense prey - some scientists have suggested that prey may brush against the hairs, and allow the whale to determine when it has found a high enough prey density to begin feeding (if enough fish bump against the hairs it must be time to open up and eat).

Some think that the hairs may be used to detect changes in water currents or turbulence. It is also thought that the hairs may have a social function, perhaps being used in social situations, by calves communicating a need to nurse, or perhaps in sexual situations.

Sources

• Goldbogen, J.A., Calambokidis, J., Croll, D.A., Harvey, J.T., Newton, K.M., Oleson, E.M., Schorr, G., and R.E. Shadwick. 2008. Foraging behavior of humpback whales: kinematic and respiratory patterns suggest a high cost for a lunge. J Exp Biol 211, 3712-3719.
• Mead, J.G. and J.P. Gold. 2002. Whales and Dolphins in Question. Smithsonian Institution Press. 200pp.
• Mercado, E. 2014. Tubercles: What Sense Is There? Aquatic Mammals (Online).
• Reidenberg, J.S. and J.T. Laitman. 2002. Prenatal Development in Cetaceans. In Perrin, W.F., Wursig, B. and J.G.M. Thewissen. Encyclopedia of Marine Mammals. Academic Press. 1414pp.
• Yochem, P.K. and B.S. Stewart. 2002. Hair and Fur. In Perrin, W.F., Wursig, B. and J.G.M. Thewissen. Encyclopedia of Marine Mammals. Academic Press. 1414pp.