EDUCATION | ANIMAL WELFARE
The Bird That Doesn’t Build a Nest
The White Tern (Gygis alba) would be a strong contender for the title in a competition to find the most elegant bird.
They’re a small, pure white sea-going bird with glossy black eyes. They’re so graceful and charming that some people even call them Angel Terns, and to be fair, they’re basically the Doves of the ocean.
Now, as you may know, when Terns normally nest, they form into huge colonies, stake out a claim on a strip of coastline, and lay their egg straight onto the ground.
This isn’t a bad survival strategy; after all, there is safety in numbers. But for birds, the ground is also one of the most dangerous places to be. It’s the entire reason why they spent millions of years learning how to fly: to get away from the ground. Putting your egg there seems like a risky proposition. If you put your egg on the ground, you’re just one yahoo in a four-wheel-drive away from getting your nest scrambled.
Now, the White Tern paused, surveyed the situation, and thought to itself, “Hey, we’ve got wings, why don’t we just put our eggs in a tree?’’ As far as ideas go, it wasn’t exactly original … I mean, birds have been doing it for eons.
But the White Tern has a peculiar quirk. You see, they didn’t get the memo about ‘building a nest.’ Instead, they literally lay their egg straight onto a bear branch. They find a little divot, balance the egg and call it a job well done.
And when the chick hatches, it just clings on for dear life until it’s old enough to fly.
Now, you probably think that sounds like a dumb way to go about raising your young. Surely, I hear you say, “A stiff breeze would knock the egg right out of the tree.” And you would be right. Every year babies are lost if a storm happens to blow through at the wrong time. Somehow, though, the White Tern has been a rather successful bird. They keep laying their eggs on branches, and they continue to avoid extinction.
It’s hard to know what evolutionary forces drove the Terns to go nest-less (some speculate it was to avoid nest parasites), but it has been working a treat for them. And while many of their seagoing brethren have suffered steep declines in recent years, the White Tern has maintained a steady and widespread population. They’re actually rather common and can be found from Chile and Mexico, right through the Pacific and Indian Oceans, and all the way to Madagascar.
There is one exception. Escaping to the trees has been a great strategy everywhere except one place — Guam. Given that the island is infested with Brown Tree Snakes, that probably shouldn’t come as a surprise. The introduced pest has managed to eradicate the tree-dwelling Tern from the island… But if you ignore that one example, they’re doing just fab.
So that’s the story of the White Tern, the seagoing bird that abandoned the land like so many other birds before them had done, but found its own rather unique way of doing it.
Ah, you beautiful little irresponsible parents, I love you guys.
