Expedition to Tierra del Fuego – January 31, 2002
Wind and tide prevail along the shore of Bahia Lomas like very few places in the world. A normal day brings winds of over 30 mph and gusting much higher. A storm can bring winds that would raise fear in most people. But here children play in the bow of the ferry while it rocks and crashes through water whipped to a froth by a 60 mph wind. The tide not only races through the Strait of Magellan but dramatically alters the shorebird landscape. At the neap (or inter-moon) tides the vast areas of mudflat, sandflat and salicornia marsh dry hard in the summer sun. At the spring (or full and new moon) high tide every single hectare gets flooded with a two-meter increase over the normal eight-meter tide. If you put wind and tide together you create an almost unpredictable situation for cannon netting. And this is our problem. In most areas of the world you can depend on birds to be at a certain place at a certain time all guided by the stage of tide. Here you cannot predict where the tide will crest and roosting birds will roost. But we are making good progress.
The morning after we stayed up to 3:00 a.m. mist netting, we set cannon nets in the salicornia marsh and soon had roosting knots and godwit in the area of the net. But the tide gushed water into the area and we had to retreat or have the cannons and nets flooded. It was a disappointment to the children and teachers of the Cerro Sombrero Middle School who had come to our camp to witness our work. But while part of the team roamed the entire study area to determine the distribution of the flock, Olivia, Ricardo and Clive spent the morning with the children giving them a through education in shorebird ecology and the importance of Bahia Lomas to the red knots and Hudsonian godwits. The mayor of Cerro Sombrero, Ricardo Olea Celsi, came with the class and was either impressed or took pity on us and invited us to dinner at his home.
Mark, Mandy, Brad and I found a flock of whimbrel on the bayfront farthur north of our camp. They roosted along a high beach of gravel almost beneath a pallid peregrine eyrie. Whimbrels nest in the low tundra, winter in the low arctic, and stopover in the mid-Atlantic area from New Jersey to Virginia. Like the red knot and Hudsonian godwit, whimbrels rank high in the North American Shorebird Monitoring and Conservation Plan, but in nearly all the areas they occur, they are almost impossible to catch. With the tides flooding most of our catch areas, we decided give it a try. The following day (Wednesday) we set our cannons and within an hour caught 150 Magellanic oystercatchers and 47 whimbrel. As far as we know this is the first catch of whimbrel in their entire 9,000 mile migratory route.
We had two additional accomplishments. First, the children and teachers of the Cerro Sombrero Middle school quickly organized a second field trip, on our invitation, and we had 20 thirteen year-olds helping us work on the birds.
Second, Anna Marie and Olivia, who were taking blood samples from most of the captured birds now had a new subject. They needed a long distance migrate (unlike the oystercatcher that lives entirely in southern hemisphere) so they could study the diseases of birds migrating between the Northern and Southern Hemisphere. Anna Maria’s Ph.D. thesis depended on us making a good catch, and to her relief, she had at the whimbrel.
To cap off a full day, several of us gave presentations in the school auditorium and to the citizens of Cerro Sombrero about our work. Alexandra spoke of her own thesis work at the University of Chile on stopover ecology of shorebirds on the Chilean coast and Luis Espinosa presented his work on the national census of birds in Chile, especially at Chiloe Island. I spoke on our work on the red knot from the Arctic to Tierra del Fuego. Afterwards, we were rewarded with a feast at the home of Ricardo Olea Celsi, the mayor of the town.
Lawrence J. Niles, PhD
Chief, NJ Endangered Species Program