January 12, 2009
Much of the work we’ve done with Adelie Penguins this season has centered around the use of flipper bands and satellite tags, two different ways of tracking individual birds.
Flipper bands are cheap, and thousands of penguins have been banded here over the years. Flipper bands wrap around the birds’ wing near their armpit, and stay on for life. A number impressed into the metal identifies the bird. Over the last couple months, I’ve spent up to 8 hours each day searching for banded penguins and writing down their numbers. All those observations go into a big database, which can eventually, through sheer numbers, tell us a lot of information about their habits and movements over a lifetime.
Satellite tags cost $5,000 each and give us detailed short-term information about penguins’ feeding behaviors. We tape the tags to adult birds at their nests and wait for them to go out to sea, catch some fish, and return to feed their chicks, when we retrieve the tag. The birds also carry a small radio transmitter that we can hear using telemetry equipment in the hut, so we can tell when they’ve returned to the colony (and when it’s time to run down to retrieve their tag). Satellite tags not only measure position (by satellite, duh), but record information about light levels, pressure, and temperature which tells us how deep they dive underwater, how long their dives last, etc. It’s a pretty neat system. We will put 1,000 flipper bands on penguins this season (all in one day, in a week or two), but we only have 5 satellite tags – they’re a precious commodity! I bet we’d get a hefty sum for them on the black market. Well, maybe not.