BBC Earth

I am enjoying the Planet Earth II series that was released in January 2017. Produced by BBC Earth with state-of-the-art technology, the nature documentary follows wildlife on islands, mountains, jungles, deserts, grasslands, and cities. The occasional intrusion of whimsical anthropomorphism (adorable antics of befuddled mammals, zany courtship rituals, and tender family bonding moments) does not detract from the stunning photography in this must-see series.

The first episode, “Islands,” reveals that 20 percent of the earth’s species live on islands, though species extinction occurs more often on those land forms. The limited gene pools allow rapid evolution, but also greater vulnerability to outside forces. The Island episode features a pygmy sloth endemic to a Caribbean island where its ancestors were trapped when sea levels rose at the end of the last ice age. On the Galapagos island of Fernandina, a riveting sequence shows marine iguana hatchlings being chased by swirling masses of racer snakes.

This Planet Earth episode put me to mind of one of my grandfather’s early letters from Wake Island, not long after he had arrived with the Pioneer Party in January 1941 to begin construction of the naval air station:

Life at Wake moves on apace. A snail’s pace. Which is a poor simile, as we have no snails. Our nearest approach is hermit crabs, a preposterous little creature about the size of a small alarm clock. He literally obeys the biblical injunction to pick up his bed and walk: always going nowhere in reverse. . . . They are very sensitive to the approach of any moving thing but their only defense is to cuddle up as snugly and trustingly as possible in their combination bed and house that they carry on their back. . . .

All of which serves as an introduction to a line of thought that engrosses me tremendously. That is an attempt on my part to correlate life as I see it on this island to life elsewhere in the light of the theory of evolution and along the line of philosophic thought. I think we may accept it as true that in a diminutive sense we may call this a continent. It is removed from any other land by a thousand miles of sea, an almost insuperable barrier to any forms of life except migratory fowls and it does not lie in any of their lanes of travel. So we may say that life as it exists is peculiar to this place, noting as irrelevant that the same condition exists on many other isolated Pacific Islands. The strongest argument for this idea is the fact that life that is native to this island could not exist if a single predatory influence were transplanted here.

Of the birds, the majority are boobies (a well-named bird), next the frigates, a sort of benign buzzard, some snipe, the only ones with a chance of survival, and—shades of a crossword puzzle—a species of rail bird. These last look somewhat like a quail but cannot fly. The boobies and frigates are very tame, or should I say have not sense enough to be afraid. They set up a plaintive sort of clamor in a scolding sort of fashion when approached but won’t fly until you are about ten feet away. Then they usually get all tangled up in the limbs of the tree or bush they are roosting on and get mad at themselves, the bush, and you. They have no control of themselves and regurgitate about this time. On Peale Island there is also a species of moaning bird (their name) that live in the ground and make a sad sort of cry like a lost soul in torment. You can readily see that none of these would be able to cope with life as it has existed on any of the mainlands for the last million years. They would be exterminated almost overnight.

The hermit crabs I spoke of and an abundance of rats that resemble an overgrown sort of field mouse are the only forms of ground life that exist in any numbers. There may have been others that these crude forms have succeeded in eliminating, a possibility that opens wide vistas of thought.

On the whole I would say that the island does not support one half the life it is capable of. On the other hand the sea around us is literally alive with fish and all forms of marine life. That this abundance exists under the highest competitive system leads to the conclusion that this competition is a necessary corollary to the development of the higher orders or species. I know that the big fish eat the smaller ones but am puzzled as to what sustains the least of them.

The conclusion is inevitable that one must live dangerously and set his hand against his neighbors in order to achieve his strength and fulfill his destiny. Being a humanist at heart I find no comfort in all this and endlessly seek some other solution. Does all this sound screwy to you and do you think the islands are getting me? (Building for War, 66-67 [Harry Olson to Donna, February 7, 1941])

Less than five years after Harry wrote that letter, the little Wake Rail that couldn’t fly had gone extinct, victim of starving Japanese soldiers during the occupation. After the war, American residents brought pet cats that multiplied and went feral, threatening other bird species until a feral cat eradication program was completed in 2005.

Polynesian or Pacific rats colonized the Pacific islands hundreds of years ago, hitchhiking with seafaring human explorers. And the “abundance of rats” remains strong on Wake Island, despite every human attempt over the last eighty-plus years to mitigate it. The most recent rat eradication program (the preliminary phase was underway when I visited the island in 2011 – and I remember betting on the rats at the time), went into full operation in 2012 with strict food, garden, and garbage protocols; bait stations; and aerial spraying until there were no rats to be seen. Then there was one . . . and then two, and now the main island is flush with rats again. Rat-shooting expeditions – a popular pastime on Wake ever since Pan Am first set up business in 1935 – don’t even put a dent in the population, but give the human residents some release.

Given the preponderance of rat life on islands, I wonder why the Planet Earth II folks didn’t include them in the episode. Then again, high-def shots of even the tenderest rat moments or adorable antics would be a hard sell.