On our Expedition to Study Shorebirds along the Northern Coast of Brazil
By: Dr. Larry Niles, LJ Niles Associates LLC
The largest mangrove forest in the world covers the Brazilian coastline at the equator near the mouth of the Amazon river. The forest extends out into the Atlantic in long peninsulas tipped by wind swept and mostly inaccessible beaches. The forest, beaches and their long intertidal mud and sandy low tide flats support the largest wintering population of shorebirds in the hemisphere, perhaps the world. The red knot, a listed species in both North and South America, also uses this remote tropical coast.
With scientists from the U.S., Canada, England and Brazil, we will attempt a large scale mapping of this important habitat using state-of-the-art satellite mapping. We will do this from a 50-foot catamaran and two zodiacs hopping from one mangrove estuary to another and conducting bird surveys targeting key areas over a 150 mile-section of the coast. We will be the first to survey some areas. Our goal is to figure out the main threats to both bird and habitat.
To understand the importance of this area one has to think about it like a shorebird. Although born in the Arctic they actually spend only a few months there. They spend a few months moving from their nesting area to their wintering area. They spend the rest of their lives, the majority of their year in the wintering area. A threat to the wintering area would be grave.
Most of our survey zone is part of the Reentrancias Maranhenses, a protected area of the state of Maranhao, Brazil. Our catamaran captained by William Thomas will leave from a small town near the city of Sao Luis, Brazil. From there we will sail along the coastline moving in and out of the mangrove islands to survey shorebirds, habitat and marine invertebrates. We will “geo reference” all data, or take detailed coordinates so the data can be reproduced on satellite mapping.
Satellite maps aren’t really maps as most people understand — pictures or drawings of a section of the earth — they are digital files of remotely sensed data, they are only wavelengths of light that must be interpreted to represent actual habitat. We will train the satellite data so that each habitat will be represented by a combination of spectral data — colors in sense.
Once completed, we can relate the habitat maps with information on birds, their prey and equally important, the threats to the birds and prey. For example, shrimp farming is growing in this area. Entrepreneurs are stripping the intertidal zone of mangrove forest, diking the area and then growing shrimp. Once the area accumulates too much waste and chemicals, they abandon the site and move on to damage another mangrove forest. We will determine which areas are of importance to the birds and potential targets for shrimp farmers. But there is more: oil spills, disturbance from tourists, water pollution are among many.
Over the next three weeks, we will be reporting on our work on this blog.
Learn more:
- Conserve Wildlife Foundation’s Online Field Guide: Red Knots
- Conserve Wildlife Foundation’s Shorebird Project
Dr. Larry Niles has led efforts to protect red knots and horseshoe crabs for over 30 years.
