Expedition to Tierra del Fuego – February 4, 2004
On our fifth campaign to Tierra Del Fuego, we hope to achieve a variety of scientific and conservation goals focused on the red knot and their chief non-breeding or wintering area on Bahia Lomas. Guy Morrison and Ken Ross will continue the aerial survey of all shorebirds species along the Atlantic coast of Argentina and the Chilean coast of the Straits of Magellan. Our main team, composed of Chilean, Argentine, Dutch, Canadian and American biologists, will conduct several projects including red knot capture and banding, foraging efficiency, and invertebrate prey inventory. Concurrently, we will continue our effort to assist Chilean officials at the provincial and national level in their efforts to seek international recognition of Bahia Lomas, where over 80% of the Western Hemisphere’s red knot population winters.
Bahia Lomas is a small bay on the south side of the infamous Strait of Magellan, home of beaked whales, dolphin, and porpoise whose skulls are scattered throughout our coastal study area.
It takes three days to get to Bahia Lomas and set-up camp. Supplies must be purchased in the town of Punta Arenas, equipment in storage must be gathered and packed for the four hour trip to our camp site, and we still have to set up our camp.
On the day of our arrival we moved quickly out to the shore of Bahia Lomas. The bay’s intertidal floods are extensive. The 10 m tide floods over 5 km of mud and sand when the moon is full and new. Through the generosity of both the Wildlife Conservation Society and NJ Audubon we are able to purchase a new ATV for our use on the flat and for the continued use by Chilean biologists Ricardo Mateus and Olivia Blank as well as other Chilean biologists working to understand and protect the bay.
Our first scan proved disappointing. With the increased mobility offered by the ATV, we determined that we were still several days away from being able to capture birds by either mist nets or cannon-netting. Based on our previous work, we know we need to trap the birds at the highest of the high tide. We caught best with mist net at night during high tide with no moonlight. Even slight moonlight will deter birds from flying into the nets. With high tide well before sunset, we will have to wait at least another night, perhaps two.
After a brief meeting with Ken Ross and Guy Morrison, we learned some very good news, that the knot numbers had remained roughly the same as last year. This is good because the Delaware Bay survey of red knots, conducted last spring, had fallen by 50% to less than 17,000. Why did the numbers fall? Was it because birds had died, or because they were no longer using Delaware Bay? Either is bad, but the latter is preferable, and the likely cause according to this year’s survey.
Kim Korth 2/4/04