Gulf Coast Bird Observatory
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  American Oystercatcher Study

Project Partners:

Gulf Coast Bird Observatory
Texas State University
Texas A&M Kingsville
University of Houston Clear Lake
Environmental Institute of Houston


National Fish and Wildlife Foundation
U.S. Fish and Wildlife Service Coastal Program
George and Mary Josephine Hamman Foundation
Jacob and Terese Hershey Foundation
The Trull Foundation

Project Abstract:

GCBO has an ongoing research project investigating the status of the western Gulf population of American Oystercatcher (Haematopus palliatus palliatus), a migratory species of high concern in the U.S. Shorebird Conservation Plan and a National Fish and Wildlife Foundation priority species. Although much was known about the life history traits and threats to Atlantic Coast oystercatchers, little was known about the challenges faced by this species in the western Gulf until we began our investigation. As a result of our work, we have gained much knowledge about the life history of Gulf coast oystercatchers. Our observations have shown that western Gulf oystercatchers prefer to nest on bay islands rather than beaches, sandbars, shell rakes, and salt marsh islands as they do on the Atlantic coast. They are subject to similar threats as Atlantic coast birds such as overwash, predation, and human disturbance. Because of where western Gulf oystercatchers nest, avian predation by Laughing Gulls is a much greater threat than mammalian predation and pairs nesting on islands without large Laughing Gull colonies fare better than those on larger islands unless there is a significant weather event that causes nests on smaller islands to be overwashed. Human disturbance from recreational boaters and fisherman exacerbates the gull predation problem because it causes eggs and chicks to be without parental protection. The few pairs we have found nesting on the mainland or on islands that are connected to the mainland at low tide have been subjected to a number of predators other than Laughing Gulls including: coyote, opossum, and feral cat. We have found no oystercatchers nesting on beaches in the western Gulf.

This project is coordinated by Dr. Susan Heath, GCBO avian conservation biologist. Dr. Heath has worked with three graduate students on this project to date. A synopsis of each of their results is below.

Alexandra Munters, M.S. Texas Statue University 2014
Nest Site Selection by American Oystercatchers (Haematopus palliatus) on the Upper Texas Coast

Lianne Koczur, M.S. Texas A&M University Kingsville 2013
Reproductive Success of the American Oystercatcher in Texas

Amanda Anderson, M.S. University of Houston Clear Lake 2014
The Factors Affecting Productivity and Parental Behavior of American Oystercatchers in Texas

Through five field seasons we monitored 368 nests and color banded 160 adult and 133 chick oystercatchers. The color banding program is allowing us to learn much about the distribution of oystercatchers in Texas. Adults appear to be non-migratory though during the non-breeding season they wander to rich feeding areas along the coast. Oystercatchers do not breed until they are three years of age so the young birds spend about two and a half years after they leave their familial group wandering the coast. We have very little knowledge of where the young birds go at this point. Color banding is also giving us clues to how often birds switch mates, whether they are territorial year round, and whether reproductive success affects pairings. Public re-sighting of color bands is extremely important for this program. If you see a banded oystercatcher, please report it to Susan Heath (sheath at

Texas oystercatchers are banded with two identical maroon color bands with a two digit code in white above the leg joint and a single metal band on the lower right leg. Click here for a complete list of oystercatchers banded in Texas.

In 2013 we undertook a stewardship program which included posting warning signs on nesting islands and giving public education seminars on the needs of bay island nesting birds. If your birding or other group would like to have an oystercatcher presentation, please contact Susan Heath (sheath at

You can follow along with our field season from mid-February through July on the GCBO Blog

Consider adopting an oystercatcher to support this project!

Texas Banding Scheme:

Upper left: maroon color band with white codes

Lower left: no band

Upper right: maroon color band with white codes

Lower right: USFWS metal band

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