Birdlife of Houston, Galveston, and the Upper Texas Coast

Hazards for Birds

hazards for birds The greatest negative influence upon the UTC’s native ecology has been explosive human population growth that began in the mid-1800s. Table 6 dramatically illustrates population change that occurred on the UTC during a single century. human population and influence The Houston metropolitan region is the most expansive urban-industrial complex in Texas, in both population and land area, and Harris County is the third most populated county in the nation (U.S. Census Bureau 2003). Petroleum refining and petrochemical facilities that have developed along the coast are among the most substantial in the world. Growth in this area is projected to continue at breakneck pace, with Houston’s population expected to double early this century. Therefore the detrimental effects upon native ecosystems that are associated with human impacts can be expected to continue to increase in proportion to this continuing population growth. As a consequence of urbanization and industrialization , the habitats available to birds are now distributed in a patchwork that is very different from what Audubon observed. This mosaic of habitats still contains sufficient habitat and plant diversity to attract a full complement of species. However, lacking an unbroken corridor of any single ecological community or the natural gradation between communities , the number of individuals of certain species, particularly deep forest and grassland species, has declined. Locally, loss of grasslands continues to proceed at an astonishing rate. As this is being written (late 2004) another 8,300 acres of west Harris County, including the 2,000-acre Josey Ranch and the 6,000-acre Longenbaugh Ranch, have been sold to for a planned 17,000 home sites. One special region of the coast that has been heavily impacted by development is Galveston Island. References to the island and its astonishing birdlife pepper this text, involving for example migrating Eskimo Curlews, nesting Black Skimmers, and wintering flocks of Sandhill Cranes. Once a treeless expanse of dunes, marshes, and grasslands ringed by mudflats and sandy beaches, the island now supports a human population of nearly 60,000. As Will Rogers so shrewdly observed,“Acquire land, they aren’t making any more of it.” Nowhere is this more true than on an island, and Galveston is no exception. Coastal ranches and other private holdings are rapidly being parceled out for residential development. As we write, over 1,200 more subdivision lots are being proposed or actively developed and several condominium towers of up to 15 stories are planned, all in an area that in 1900 was devastated by a hurricane that killed between 6,000 and 12,000 people, at that time the greatest natural disaster to ever hit the United States. predation and mortality Threats to birds vary with the family and habitat considered. For example, migrating shorebirds appear to have a limited set of predators on the UTC. Table 6. Population Growth of UTC Counties, 1890–2000 Persons per square County 1890 1940 1990 2000 mile, 2000 Brazoria 11,506 27,069 191,707 241,767 174 Chambers 2,241 7,511 20,088 26,031 43 Ft. Bend 10,586 32,963 225,421 354,452 405 Galveston 31,476 81,173 217,399 250,158 627 Harris 37,249 528,961 2,818,199 3,400,578 1,967 Jefferson 5,857 145,329 239,397 252,051 279 Waller 10,888 10,280 23,390 32,663 63 Total 109,803 833,286 3,735,601 4,557,700 30 birdlife of houston, galveston, and the upper texas coast Their avian threats include Peregrine Falcon, Merlin, Northern Harrier, and Short-eared Owl. Coyote, gray fox, and bobcat may take others. The greater danger lies in development of their habitat. On farms, domestic and feral cats and dogs, livestock , and machinery are known to impact nesting species such as Mottled Duck, King Rail, and Eastern Meadowlark. Automobile strikes are an ongoing and generally underestimated source of mortality. The following are just a few of the species that have been noted as local road kills: Least Bittern, Common Moorhen, Purple Gallinule, King and Clapper rails, Killdeer, Willet , Long-billed Dowitcher, Buff-breasted Sandpiper, Wilson’s Snipe, Common Nighthawk, Yellow-billed Cuckoo, Barn Swallow, Yellow Warbler, and Indigo Bunting. During migration the last two species have a strong affinity for open scrubby fields and are occasionally slaughtered in considerable numbers as they fly low across the Bolivar Peninsula’s State Highway 87 into extensive stands of willow, baccharis, and rattlebox...