American Oystercatcher (photo © Alan Wilde)

American Oystercatcher (photo © Alan Wilde)

Project Partners:

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

Funding:

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

SueWithThreeChicksProject 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. 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. Western Gulf oystercatchers prefer to nest on bay islands. They are subject to overwash, predation, and human disturbance. Because they nest on islands near or within Laughing Gull colonies, avian predation 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 domestic cat.

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 and 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

We have color-banded over 300 oystercatchers in Texas and this is allowing us to learn much about their distribution. Adults are non-migratory though during the non-breeding season they wander to rich feeding areas along the coast. Oystercatchers do not breed until they are at least 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.

From 2011 to 2016, Texas oystercatchers were banded with two identical maroon color bands with a two character alphanumeric code in white above the leg joint and a single metal band on the lower right leg. In 2017 we began using three character alphanumeric codes in a triangle pattern because we ran out of two character codes that were not reverses of codes already used. Click here for a complete list of oystercatchers banded in Texas.

In 2015 we began a Citizen Science project with Audubon Texas monitoring nesting oystercatchers on the Texas coast. Volunteers monitor their pair(s) at least once a week and report the data so that we can keep track of adult pairings, nest success or failure, and other information. For more information on this program check the Audubon TERN website.

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


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

Consider adopting an oystercatcher to support this project!