There are two pairs of masked boobies with young close together on this part of the beach. From time to time the adults jab at each other. They have the whole beach on which they can spread out, but clearly to both sets of parents their par- ticular spot on the beach is the best, to be defended against all comers. The chicks vibrate their throats, ululating without noise- just the shiver and shake of down on their long necks. Their mouths hang open.
Endurance is all.
Fledged booby chicks sit on the water and dip their heads un- rler, peering around as if checking if their feet are still there. It is already a strong flier but will not achieve full maturity until it is two years old. I turn my back on the beach, with its groups of bobbing boo- bies, to face the interior. Here the island dips into a broad, shallow depression where guano was once minerl. Sooty terns occupy the entire space, about 15 acres in all.