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It's a Whale's World

It is easy for humans to feel as if we are the most highly evolved species on earth; after all, we have successfully inhabited nearly every land region on the planet and we have a highly developed social system. Our relatively large brains have allowed us to extend our potential lifespan, and we (some of us, anyway) occasionally have some time to relax, appreciate our good health, and live off our stored reserves. But there is another group of mammals that actually surpasses us in many of these categories -- the whales. So, as we contemplate the notion that we may be running out of the resources that sustain us, we should pay homage to the great whales who may have figured out the secret to a better life.

Out of the Sea . . . and Back Again
Like the whales, we are mammals, a group that evolved on land from some common ancestor that originated in the sea. We stuck to the terrestrial life, but one group of hoofed mammals gradually shifted back to the water's edge, and finally returned to a completely aquatic existence. Because we are terrestrial, it may seem as if a transition back to a life in the sea is somewhat unnatural (perhaps even a step backward), but the truth is, large mammals are probably better physically suited to a life in seawater. The salinity is about the same as the fluids in our bodies, the temperature is more constant, and the naturally occurring supply of food is nearly inexhaustible (if you like the taste of krill). Another fact to remember is that the planet we're on is more than two-thirds covered with salt water -- whales have opted for the bigger (and richer) slice of the pie!

Define "Superior"
Whales are among the few animals whose brains are larger than those of humans (a Sperm Whale brain is about nine times larger than a human brain). The whales developed brains the size of present-day human brains about 30 million years ago, while human brains didn't evolve to their present size until about 100 thousand years ago. It may be just one of the areas in which we've got a lot of catching up to do!

Whales are highly social animals, and humans are just beginning to understand how complex their social lives are. Many species, for instance, are known to hunt cooperatively. Perhaps the most unique example of cooperative feeding is the "bubble netting" technique practiced by Humpback Whales. Several Humpbacks dive below a large school of fish and swim in an upward spiral while emitting a cylindrical curtain of bubbles around the fish. Then the whales rush into the concentrated school of fish and gulp huge mouthfuls. No poles, no nets, no hooks, and no bycatch.

Another adaptation that should make humans envy whales is the location of their blowholes. Besides making it possible for them to inhale and exhale with just the top of their heads at the surface, this change in position of the opening to their respiratory system also separates it from their alimentary canal, allowing them to breathe and eat at the same time. Our own system with a single opening for these two functions allows us to choke to death on our food -- this can never happen to a whale. Whales are also probably the most long-lived of all animals. A recent study of Bowhead Whales suggests that some individuals live to over 200 years of age. Some scientists believe that all of the larger species routinely live to be well over 100. Human life expectancy (for the majority of the people on this planet) is closer to 60 years.

Where the Whales Are
The life cycles of most of the great whales of the world are remarkably similar; they migrate toward the equator as winter approaches, calve, and then move toward the poles during spring to spend the warm months feeding in the productive waters surrounding the polar regions. These great beasts pass along our shores, up and down the Pacific and Atlantic coasts, during their migrations in spring and fall, but that's not the only time to see them. You can also see whales during the summer months, without traveling to the Gulf of Alaska or the chilly waters off of Newfoundland.

On the Atlantic coast, summer whale watches are offered from Long Island to Maine. Fin (or Finback), Humpback, Minke, and Right Whales can be seen off the north Atlantic coast from April to October. These whales are attracted to relatively near-shore waters by the huge congregations of crustaceans and small fish that occur where upwelling deep ocean waters meet shallower waters at the edge of the continental shelf. One of the best whale-watching destinations is the Stellwagen Banks, located just beyond the tip of Cape Cod at the mouth of Massachusetts Bay.

On the California coast, there are several places where whales may be seen during the summer. Orcas, and Humpback, Blue, and Minke Whales may be found near the Farallon Islands, just west of San Francisco, or congregated in the Monterey Bay area. Farther south, off the shores of the Channel Islands, Blue and Humpback Whales are seen in increasing numbers each summer. Of course, the most numerous California whales are the Gray Whales that migrate up and down the coast each year. The best time to see them is during the spring when they move north to their summer feeding areas near Alaska. Females and their calves pass just offshore in order to avoid the open ocean where Orcas and Great White Sharks pose a threat.

Summer is a great time to go on a whale watch and marvel at the great size and extraordinary grace of our fellow mammals. And as you watch these behemoths glide by, consider the fact that they may have evolved the perfect life style, and that they just may have outsmarted those of us who have remained on the shore.

 

 

 

 

 

2007 eNature.com