Completed Projects

Eastern Willet Migration Project (2016-2018)

Project Partners:willet1

U.S. Fish and Wildlife Service
Conservations Services International

Project Funding:

U.S. Fish and Wildlife Service


While the eastern Willet remains a common and conspicuous species in many eastern salt marshes, the future of the habitat it uses is uncertain. Coastal wetlands are limited in extent and although many salt marshes in the eastern U.S. have protected status, their future may be in jeopardy as the effects of sea level rise due to climate change begin to be felt. The habitats Willets use in Central and South America face these same uncertainties and are also under threat from habitat loss due to mangrove destruction and changing land use patterns. Because of this and other threats, the Willet has recently been added the USFWS conservation watch list as a species requiring management attention.

We know little about the paths Willets take on migration or the stops they make along the way. Although such information is essential for effective conservation decision making, we have not yet established these linkages for this species and can only monitor populations at one end of migration or the other without the benefit of knowing where these populations are going to, coming from, or where they are stopping along the way.

Eastern Willets may migrate to the northern coast of South America, an area important for a variety of wintering migratory birds and where 75% of South American Willets occur during winter. Unfortunately, at this point, there is little definitive information on the winter destination of North American breeding populations. The Smithsonian Conservation Biology Institute, the Nature Conservancy, the Biodiversity Research Institute, and Biodiversity Works have been engaged in a Willet migration study since 2010. The primary field sites have been in New Jersey and New England.

willet3They deployed archival data tags (geolocators) on 23 Willets in New England and the results from these birds show remarkable similarities in the locations of stopover and wintering sites in northern South America. In spring 2015, GCBO in collaboration with the U.S. Fish and Wildlife Service at the Texas Mid-coast Refuge Complex joined this project and deployed 10 archival data tags on breeding eastern Willets at the San Bernard National Wildlife Refuge. In 2016 we hoped to recover these tags and deploy 15 additional tags to gather additional data on the migration routes and wintering areas of Texas breeding Willets.

Sand Plover Study (2008-2009)

In 2008, GCBO was awarded a one-year contract from Texas Parks and Wildlife Division to census sand plovers along the Upper Texas Coast. This study focused mainly on Piping Plovers but Snowy and Wilson's Plovers were also included. From January through December, we surveyed plovers on the UTC and recorded numbers of birds, habitat characteristics, and human disturbance. Although regular Piping Plover surveys occur on the breeding grounds, at the time of this survey there had been no recent winter surveys on the UTC in Texas. These data enabled our staff ornithologists to determine the habitat characteristics preferred by wintering plovers, determine what the threats were to those habitats, and estimate the population size supported by the UTC in winter. This study provided an excellent overview of how hurricanes change the habitat and plover response to those changes because Hurricane Ike occurred in the fall of this study.

We surveyed the upper Texas coastline from the mouth of the Sabine River to the mouth of the Colorado River, a straight-line distance of about 200 km. between January 2008 and January 2009. We recorded 1131encounters with Piping Plovers at 748 locations marked by GPS coordinates. We observed any interactions between Piping and Snowy and Wilson’s Plovers which share the same coastline and recorded color marked Piping Plovers so we could observe the movements of uniquely marked birds. We compared our GIS data with published Designated Critical Habitat areas for the species. We attempted to measure human disturbance as a factor in Piping Plover wintering distribution by comparing our survey results between a moderately heavily used beach with an adjacent beach with little or no human disturbance. Our study was seriously interrupted by landfall of Hurricane Ike at approximately the mid-point of our study area in mid September. The storm affected the distribution of Piping and other small “sand plovers” and we attempted to document the movements of plovers in response to the severe habitat alteration caused by it. Finally, based on a year of observation of Piping Plover distribution we attempted to assess any imminent threats to the areas where relatively high numbers of Piping Plovers were consistently encountered.

To read the full report, click here: PIPLFinalReport102209

Ivory-billed Woodpecker Study (2005-2008)

On April 28, 2005, the Secretary of the Interior announced that at least one individual Ivory-billed Woodpecker Campephilus principalis had been rediscovered in bottomland forest in east central Arkansas after a period of 60 years of presumed extinction (Fitzpatrick, et al., 2005). This announcement raised the realistic possibility that the species may have survived into the twenty-first century in other parts of its historic range where suitable habitat exists, including the corridors of the Trinity, Neches, and Sabine Rivers and their larger tributaries in southeastern Texas (Oberholser 1974, Shackelford 1998). In 2005, we set out to ascertain within a two year time frame the status and distribution of Campephilus principalis in that portion of its historic range in Texas in which significant quantities of suitable habitat are thought to exist to support a small population of the species.


        We surveyed an area estimated to be less than 10% of the remaining bottomland forest along the lower Neches and Trinity Rivers. Based on these observations and ground visits to areas where privately owned forest adjoined public roads we believe that we surveyed the forest of the highest quality for potential surviving IBWO remaining in the region. Our failure to find other suggestive evidence that Ivory-billed Woodpeckers exist in the areas searched leads us to conclude that there probably is not a remnant population of the species in southeastern Texas.

        To read the full report, click here: Final Report- Texas Ivory-billed Woodpecker Project

        Project Prairie Birds (1998-2003)

        Coastal prairies, the most endangered ecosystem in Texas, are the primary winter destination for two dozen species of migratory grassland birds including large numbers of sparrows, pipits, and wrens. In winter, these birds use a mosaic of remnant native prairie, agricultural fields, improved pastures, marshes, and hedge rows. In response to the need for new information, the Gulf Coast Bird Observatory (GCBO), in conjunction with project partners, Texas Parks and Wildlife Department (TPWD), Texas Partners in Flight, and Raven Environmental Services, Inc. developed and initiated Project Prairie Birds (PPB) in the winter of 1998. Designed as a 5-year, citizen-science project, we hoped to collect bird and vegetative data to map distribution and identify specific habitat requirements of over-wintering avian grassland species in Texas coastal prairies and surrounding areas. In addition to identifying the area-distribution of winter grassland birds, we hoped to find associations between our vegetative samplings and avian censuses that may identify habitat preferences for target species.


              Coastal prairies are the primary winter destination for two dozen species of migratory grassland birds and losses of this habitat have proven detrimental to their populations. As a result, some of Partners in Flight’s (PIF) highest priority birds are grassland species. To examine grassland bird use of coastal prairies, Project Prairie Birds survey methodology was designed and field work was initiated in 1998. Avian surveys were conducted at 34 sites, each with multiple transects for a minimum of two years by all-volunteer, three-person crews identifying all species flushed from vegetation. Seasonal vegetation surveys measured five variables using five one square-meter
              sample areas. We also measured vertical thickness using a density board. We selected nine sites (26.5%) with three or more years of survey data for analysis. Thirty-nine species were detected of which 36% have PIF combined species assessment scores of 10 or above. In addition, 24% of the individuals were Le Conte’s Sparrows which are a PIF Tier II priority species. A multiple regression between abundance and vegetative data for these two species showed a weak but significant correlation between Sedge Wren and the 0.5 m vertical thickness parameter (R2  0.1544, p  0.0001) but no significant relationship for Le Conte’s Sparrow. This is likely due to high variances in the data as over-wintering location choice for these species is a function of climatic variability.

              To read the full report, click here: PPB Paper

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