Peter’s talk took us across the Pacific Ocean, following the stories of a few remarkable animals. Two in particular.
He started with two species of albatross that live on Midway island. It was a bit of a puzzle why and how these two closely related species lived together so closely. The albatross for a long time was seen as a problem and the Navy waged war against it until they figured out how to coexist (the albatross managed to do well enough in the battle that a statue was erected in its honor).
The scientific mystery was not solved until they tagged the animals as they left their chicks behind to find food. The chicks are mostly safe and sound on the island (the Navy aside) with not predators, but little nearby food. What the scientists discovered was that the animals flew thousands of miles to feeding grounds, and that is where the species separated: one flew to the Bering sea, the other flew to California.
Parent albatross leave their chicks for a month at a time taking 4 days to fly to near their destinations: upwellings where they could store up on the food they needed for themselves and their chicks. Nearly 7,000 mile round trips. The birds become flying “fat bombs” converting their food to an awful smelling oil that is hard to remove from one’s hands. The birds are also built for the long distances, with their long wings the wind can carry them the whole one way distance without flapping a wing, perhaps even sleeping on the wing.
Equally surprising was what Peter Pyle and his colleagues found with sharks in the Farallones. Peter worked their studying birds, but soon became fascinated with the local sharks (only confirmed after 1980 that they were Great White’s) working to study and protect them.
When they started tagging sharks they found the sharks were swimming thousands of miles. Some would appear regularly in Hawaii, almost all of them would spend some time in a random place in the South Pacific (a mating area most likely, but there doesn’t seem to be any good reason for the spot — perhaps it is some deep deep ancestral spot where there used to be a coastline, sharks being one of the older species on the planet).
They also found that there was a difference between males and females. Male sharks would be gone a year, but females would be gone for two. It’s suspected that the female sharks give birth to their young on the other side of the Pacific, before they make their way back.
He ended the talk touching briefly on a few other journeymen species: leatherback sharks swimming from Indonesia to California (as we’d seen in an earlier talk from this year) and the Bar-tailed Godwit flying some 13,000 miles in its migration to New Zealand.
Astonishing journeys, reinforcing some how little we know about some of the animals that we share the planet with, even some animals like the Great White Shark that we obsess over.
SF Natural History Series 