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Ocean Watch Susan Scott |
Baby turtles take
wrong turns on TernOne of the best daily chores here on Tern Island is searching for baby turtles that hatched in the night and got lost.
The job requires you to get up at first light, fetch a bucket and then walk around the island looking for hatchlings either wandering the runway or banging against the bulkheads that hold this man-made island together.
This turtle trek, which includes releasing our finds on a beach turned pink by morning sun, is rotated. Every 5 days, each of us gets to offer a helping hand to Hawaii's threatened green sea turtles.
But as wonderful as these walks can be, they have a solemn side.
It's called natural selection and it can muddle the emotions of even the most experienced wildlife workers.
During my last turtle walk, I stepped outside and immediately spotted a hatchling scampering across the crushed-coral runway.
Few wildlife sights are more poignant than watching a baby sea turtle running for its life, in daylight, by itself.
Usually, hatchlings emerge from their sand nest at night and all at once. They don't each hatch at the same instant, though.
The first ones out of their leathery shells lie motionless just beneath the sand while their siblings below work free of their shells.
You can see this happening on the beach. A round depression appears in the sand, a foot or so in diameter and an inch or two deep. This circle of sand intermittently heaves and ripples in a tiny earthquake of budding life.
Sometimes, the commotion below pushes the leader partially out. I saw this happen last week and thought the flaccid turtle, with sand packed in its eye sockets, was surely dead.
This sand-swelling phase can last a few hours or a few days, depending on how long it takes all the turtles to hatch. The nest I found rising and falling was doing so at 5 a.m. It wasn't until 9 p.m., however, that the earthquake became a volcano. The limp leader sprang to life, and in one of the most thrilling events in nature, led its erupting brothers and sisters to the sea.
Unfortunately, some hatchlings lose their way and that's when we humans get involved.
After picking up my first runway turtle, I spotted another, and then another, and soon I was jogging down the airstrip, adding lost babies to my bucket.
But I didn't get them all. When I straightened up near the end of the island, an immature frigatebird stood before me, and from its beak dangled a struggling turtle.
Hawaii's frigatebirds don't usually eat turtle hatchlings, nor are their short legs and small feet suited to standing on the ground. This individual bird, however, had used an uncommon behavior to take advantage of a turtle headed the wrong way at the wrong time.
The frigatebird took off in the strong tradewinds, and with a toss of its head, that bird ate my turtle.
I knew it was a privilege to see such an elegant example of natural selection, and I valued viewing this link in the marine food chain. But later that morning, as I watched my rescued turtles scurry to the ocean, I felt glum. I grumped about the harshness of life all the way back to the barracks.
Survival of the fittest may be the basis of life on this planet, but when it comes to baby turtles, it sure is hard to watch.
See the Columnists section for some past articles.
Marine science writer Susan Scott can be reached at http://www.susanscott.net.
