- Published on May 13, 2010
Earlier this month Ryan Wallace, the boating coordinator, approached me in the lab and asked if I wanted to come birding. I wasn’t involved with dive ops that day so I quickly layered up, and grabbed my dry bag (a waterproof bag to hold my camera and extra clothes in case I got cold or in the unlikely but nevertheless possible event that I somehow ended up in the water). I put on a mustang suit, the huge, warm, waterproof orange jumpsuits we wear in the boats during the wintertime, and met Ryan and Jeff at the dock.
We pushed our way through the brash ice to Humble Island, sandwiched between Litchfield and Amsler Islands. “Birding” for me that day meant hiking along after Ryan and Jeff and recording data as they weigh giant petrel chicks.
Giant petrels are named so because they are huge. Adults weight between 7 and 17 pounds and have a 6-foot wingspan! The chicks of such large birds are similarly large. They are truly giant baby birds, and they are covered in fluffy gray down.
Giant petrels lay a single egg in a ground nest on land. They sit on the egg for about 2 months before it hatches. The hatched chicks are brooded for a few weeks, and after that they are left on their own while the parents hunt and scavenge for food. The parents return to the nest every so often to regurgitate food for the chick, but other than that the baby petrels just hang out in the nest alone, growing. The chicks fledge after about 4 months. This means that they lose all of their baby down and fly away.
Part of the Long-Term Ecological Research (LTER) group focuses on seabird and penguin populations. They monitor and census seabirds and penguins every year so they can investigate long-term changes in populations and try to find out what causes those changes. They do this by comparing their population data with other data sets; things like temperature, sea ice coverage, and human activities such as tourism.
The giant petrel chicks on Humble Island hatched this past January. The LTER “birders” kept track of each and every giant petrel chick on Humble. When the chicks were very young and growing fast, they went out every other day to measure beak-length, feather-length, weight, etc. The goal is to collect data on each of these petrel chicks from hatching to fledging. The petrel chicks are fledging right about now, May, yet the LTER scientists are only on station for the summer season, ending in early April.
So how do the birders get their complete data set every year? They ask the wonderful Palmer station science support staff for help. Ryan Wallace and Jeff Otten, the IT specialist, have been the winter birders for the past 3 and 2 years, respectively. It’s not easy to weigh a huge baby petrel chick, but these guys really have a way with gigantic baby birds.
When I went birding, right at the beginning of May, all 25 of the original petrel hatchlings were still nesting on Humble. None had fledged yet, but I got to see all of the different stages of chick maturity. Some of the chicks were still completely covered with their fluffy gray down. Some only had chunks of down here and there, and some had hardly any at all. Some birds had lost all of their down and looked exactly like adults, but hadn’t yet learned to fly.
In the 2 weeks since then, 21 of the 25 fledgling birds have flown the nest to begin their seafaring lives. Ryan and Jeff are still going out twice a week and will continue to do so until the last bird has fledged and the data set is complete.