Expedition to Tierra del Fuego – 2001: Introduction
On February 1, biologists with the NJ Division of Fish and Wildlife’s Endangered and Nongame Species Program will lead a team of other biologists from the US, Canada and Chile to Tierra del Fuego, at the southernmost tip of South America, to study the Red knot. The knot, a dove sized, red breasted shorebird, flies an incredible 10,000 mile journey from arctic breeding grounds to winter in Tierra del Fuego. On their return journey to the Arctic, the birds run out of fuel and stopover on the Delaware bay, where they gorge on the eggs of the horseshoe crab. The Delaware Bay is the most important stopover on the flyway. The purpose of our expedition is to determine the change in the status of the red knot population as a result of declining horseshoe crabs on the Delaware Bay. We will report on our progress in a web field journal at this location over the next 10 days.
This is our second expedition to Tierra del Fuego. Last year, a team composed of biologists from the ENSP, Royal Ontario Museum, Canadian Fish and Wildlife Service, and Argentina conducted aerial and ground surveys of several wintering sites in both the Argentine and Chilean coast of Tierra del Fuego. We were reproducing a count done by the Canada Fish and Wildlife Service in 1986, so that we could get a new estimate of the wintering population of knots and start a yearly survey.
We found 45,000 knots in one bay, Bahia Lomas in Chile and a smaller number in Rio Grande and Bahia San Sebastian in Argentina. In total, we found nearly ¾ of the entire red knot population, including many birds banded on the Delaware Bay. After completing our aerial counts we found our way to the shoreline of Bahia Lomas and conducted ground surveys, scans for bands, and planned for this year’s work.
We are also studying red knots in their arctic breeding areas at the same time. Our first job was finding where the Knots of Delaware Bay nest. We found breeding areas with the use of radio transmitter attached to the birds on the Delaware Bay. This year we also spent 10 days on the ground finding nests, following radio tagged birds and conducting studies that gave us important baseline data for the population. Our work was presented in a web field journal at this site.
Our goal for all this work is to help determine the status of red knots, and the other five species of shorebirds that stopover on the Delaware Bay. The bay’s crab population is declining, causing a sharp decline in the availability of crab eggs. Where once there were millions of crab eggs there are thousands or none at all. Each year more and more birds fail to reach sufficient fat reserves to make the journey to the Arctic. As more and more knots fail to breed, eventually the number of young will decline. At first, it will be hard to notice because of the difficulty in distinguishing young birds from adults. Eventually, adults will die natural deaths and not be replaced. At that point, the population may fall fast.
Our trip to Bahia Lomas will help. We will be counting the total number of birds from a small aircraft, then confirming it with a ground count. Concurrently, we will try to determine the patterns of habitat use on Bahia Lomas, information that is currently unknown. For example, while we visit the bay, the moon will wax to full on Feb 10. This will result and additional 3 meters of tide ( 9.6 ft) on top of the current 9 meter tide (29 ft). By comparison, the tide range in NJ is about 6 ft. Studying the movements of the birds in response to weather and tide will help us with our last important goal. Through observation and capture by mist nets, we will try to corroborate the aerial counts, estimate the proportion of young birds and finally band birds so they can be re-sighting throughout the rest of the flyway, including the Delaware Bay.
That is, of course, if doesn’t rain the whole time we are there. Tierra del Fuego has been receiving an unprecedented abundance of rain and it could make our work difficult.
Our team includes experience shorebird biologists from all over the western hemisphere.
- Larry Niles, Endangered and Nongame Species Program, Division of Fish and Wildlife.
- Sherry Meyer, Endangered and Nongame Species Program, Div of Fish and Wildlife
- Steve Paturzo, Endangered and Nongame Species Program, Div of Fish and Wildlife
- Amanda Dey, Endangered and Nongame Species Program, Div of Fish and Wildlife
- Bruce Luebke, Cape May National Wildlife Refuge, US Fish and Wildlife Service
- Rick Lathrop, Remote Sensing Lab, Rutgers University
- Brad Winn, Nongame Program, Georgia Division of Fish and Wildlife
- Steven Brown, Manomet Bird Observatory
- Ken Ross, Canadian Fish and Wildlife Service
- Guy Morrison, Canadian Fish and Wildlife Service
- Ricardo Matus, Shorebird biologist, Chile
- Luis Benegas, Shorebird biologist, Argentina
- Bruno Kern, videographer Canada
We received vital and gracious logistical support from: Jorge Jordan, Director Gerente, Soc. Com. Jordan Y CIA. LTDA Claudio Venegas, Professor Universidad de Megallanes Bill Weber, North American Program, Wildlife Conservation Society Stacey Lowe, North American Program, Wildlife Conservation Society Mark Peck and Allan Baker, from the Royal Ontario Museum Patricia Gonzalez, Shorebird Biologist, Argentina Nina Garfield, National Marine Sanctuaries, NOAA
This project would not have been possible without the financial support of the Wildlife Conservatoin Society, in particular Bill Weber’s North America Program, Lisa Garrison and the Dodge Foundation, the US Fish and Wildlife Service’s Delaware Bay/Cheasapeake Bay Ecosystem Team, specifically Steve Atzert, and Cliff Day’s US Fish and Wildlife NJ Field Office. Finally, we are indebted to Linda Tesauro and the Conserve Wildlife Foundation and the citizens of NJ that checked off for wildlife on their state income tax, or bought a Conserve Wildlife license plate.