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Laredo Breeding Bird Survey report available online
Galvan Ranch Breeding Bird Survey report available online
Surveys of Night Birds Along the Rio Grande in Webb County, Texas report available online
Texas is
ornithologically the richest state in the nation, supporting more than 600
documented species. Southern Texas is particularly rich in avifauna, however,
the Laredo
area (in Webb County) has been poorly studied. Even the most basic inventories
of flora and fauna remain inadequate. From 1996-1999, the Texas Gulf Coast Field
Research Station conducted breeding bird surveys along the Rio
Grande in Webb County. Two research reports (“Breeding Bird Surveys at the
Galvan Ranch, Webb County, Texas” and “Surveys of Night Birds along the Rio
Grande in Webb County, Texas”) were produced based on work conducted on the
69,000 acre Galvan Ranch, located about 60 km upriver from Laredo. A third
report, “Breeding Bird Surveys and Ecotourism Potential at Laredo, Webb
County, Texas” was completed after conducting surveys 
on public lands within
the city of Laredo. While Laredo traditionally has been outside of the usual
destinations for birders, it can now be considered a new and very exciting birding
destination in southern Texas. This trilogy of reports on the bird life of Laredo
and Webb County have contributed to that change in perception.
The Laredo and Webb County area remains largely unspoiled by urban sprawl and intensive agriculture. Much of Webb County is still dominated by extensive vistas of Tamaulipan thorn scrub, an ecosystem unique to southern Texas and the northeastern states of Mexico. The results of the USGS surveys have established that the Laredo area is a remarkably rich region for bird species. Some of the species discovered are tropical species that are very rare and geographically severely restricted even within southern Texas. Prior to the surveys, many of the species discovered were thought to exist only in very small numbers near the delta of the Rio Grande (more than 300 km downriver). Instead, however, many bird species were found to be flourishing in Webb County! Important tropical species found include the White-collared Seedeater, Red-Billed Pigeon, Elf Owl, and Green Parakeet. Three very rare species were documented in Webb County in small numbers: the Clay-colored Robin, the Gray-crowned Yellowthroat, and the Masked Duck. Other birds seen regularly in this borderland region of Texas include Green Jay, Audubon’s Oriole, Least Grebe, Ringed Kingfisher, and Common Pauraque, to name only a few.
Important management information was also gained from the Webb County research projects. This aspect of the study was included to provide landowners with recommendations for managing their properties for birds. The USGS research found that stock tanks or other freshwater ponds attract a greater diversity of bird species and bird numbers if they have irregularly shaped and gently sloping shorelines. This is a significant finding for this ranching area, where stock tanks generally are constructed in a rectangular shape with steep banks. The study also found that ponds located within 12 kilometers of the Rio Grande had a higher species diversity than ponds located further away. Tropical birds were found to prefer the Rio Grande over stock tanks.
Ed Rachal Foundation
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