National Geographic : 1967 Apr
parasites. Stolidly the ugly, wrinkled iguanas allowed the little birds to groom them, flinch ing only when a sensitive eyelid was tweaked. Darwin surmised that the marine iguanas occasionally fed on seaweed "at some little distance from the coast." We now know that they swim out to sea and dive to the bottom, propelled by their flat snaky tails. Divers have seen them at depths of 30 feet, chewing algae on the submerged rocks (page 584). Playful young seals seem to take great de light in chasing the lizards as they swim fran tically for the safety of the rocks. I supposed that, once ashore, the iguanas were without enemies-until one day I saw a Galapagos hawk plop down in their midst. It snatched a young iguana, flew off to a mangrove stub, and ripped its prey apart (page 556). Later I learned that the young must also be wary of snakes (pages 582-3). We marveled at the tameness of the hawks. They were as trusting as the songbirds and the seafowl. In curiosity they watched us from their low perches, even allowing us to shake the branches until they were forced to let go. They have been virtually eliminated from the two most heavily settled islands, Santa Cruz and San Crist6bal. Nor are they safe elsewhere. One day a visiting yacht dropped anchor at Santa Fe Island and the shore party wantonly shot the four friendly hawks that came to greet them. One of the great surprises of this tropical archipelago is the presence of penguins. We 580 saw many of these perpendicular birds stand- ing in two's and three's on the rocks, or swim ming just below the surface, literally flying through the water on stiffly extended wings. Penguins as a family inhabit the Southern Hemisphere's colder waters far to the south. But the little Galapagos penguin, numbering between 1,000 and 3,000 birds, lives right on the Equator (page 557). Sometime in the remote past a few birds of the Humboldt penguin type-perhaps inexperienced or ad venturous youngsters-must have been swept northward by the cold Peru, or Humboldt, Current, to land far from home on these is lands. The breed that has evolved is a small, runty type, but the striped facial pattern of the adults clearly reveals its ancestry. Lobster Traps Endanger Rare Birds The most fabulous bird in this never-never land, in my opinion, is the flightless cormorant (page 556). It is more truly flightless than the penguin, for it does not even use its rudimen tary wings as flippers. Instead it swims under water with big webbed feet. Its ancestors, we assume, almost certainly flew, and probably looked much like the Brandt's cormorants along the coast of California. These shabby birds sit about in group meditation, occasionally spreading their wings like tattered laundry hung out to dry. Balefully they glare at each other with their green eyes while salt water drips, 12 drops a minute, from their beaks. Like many other sea birds, they possess a special gland in their nostrils to dispose of unwanted salt.