Earth Almanac: March/April 2009

Pelican Brief

Now, on the ground or in bushes or trees along all three coasts north to southern California and North Carolina, brown pelicans are building nests of sticks, reeds, and grass. The next time bad news about native fauna plunges you into a funk, consider this bird’s recent history. Because brown pelicans incubate eggs with their feet, the shells were especially vulnerable to breaking when thinned by DDT and other hard pesticides. By 1966, the year Louisiana made it its official bird, the brown pelican had essentially vanished from the state. Recovery in the post-DDT era has been spectacular. In Alabama and the Atlantic states, the brown pelican has been removed from the endangered species list, and delisting in the other Gulf states and California may have happened by the time you read this. Though rarely celebrated for his scientific acuity, poet Dixon Lanier Merritt had it right when he observed, “A wondrous bird is the pelican / His bill holds more than his belican.” The capacity of the brown pelican’s pouch, in fact, exceeds that of its belly by a factor of three. But Merritt erred with, “He can take in his beak enough food for a week.” The bird uses its pouch merely as a net.

Easy Riders 

In the deserts of our Southwest and into Mexico, ancient beasts with elephantine hind limbs are waking from hibernation. Now is your best chance to encounter desert tortoises, well-adapted reptiles that spend 90 percent of their lives underground. By May some will be out and about as early as 6 a.m., but stressed by the fierce sun, they’ll be back in their dens by mid-morning. Desert tortoises can usually survive on moisture from the plants they eat. But as insurance against prolonged drought they drink copiously after a rain, storing water in their bladders and gradually reabsorbing it while excreting uric acid, sometimes in semi-solid form. As a last, desperate defense, a tortoise will void the contents of its bladder, so never pick one up, even if you encounter it in the middle of a road. Instead, gently herd it to the side it was headed for. This time of year males are vying for females, jousting with “lances” that protrude from the front of their plastrons. Combatants try to flip the opponent on his back. A tortoise thus vanquished can usually right itself with head and a forelimb. If not, it may overheat and die.