Northern Prairie Wildlife Research Center
Galveston Island, Texas
Open Waters of the Gulf of Mexico
Extending from the beach gulfward to the horizon, the stretch of the Gulf of Mexico that is visible from the park is noteworthy for the seabirds that periodically pass over and through its waters. In addition to the ubiquitous pelicans, gulls and terns that congregate over the Gulf, birders may also see Northern Gannets in the winter, Pomarine and Parasitic jaegers in the winter and during migrations and Magnificent Frigatebirds in summer and fall. There are winters when sea ducks gather offshore, presenting the rare opportunity to see Oldsquaw, and Black, Surf and White-winged scoters in Texas. In early spring, migrating Tricolored Herons, White Ibis, Fulvous Whistling-Ducks and Blue-winged Teal can be seen returning from their southerly wintering grounds in an endless stream moving north along the coast.
This littoral habitat ranges from the water line landward through the fore-island dunes. The vegetation on the gulfward dune faces is dominated by succulents and salt-tolerant species of plants such as gulf croton (Croton punctatus), sea-purslane (Sesuvium portulacastrum), fiddleleaf morning-glory (Ipomoea stolonifera), bitter or seaside panicum (Panicum amarum) and camphor daisy (Heterotheca subaxillaris). This community grades into a seacoast bluestem (Schizachyrium scoparium) - gulfdune paspalum (Paspalum monostachyum) community on the landward dune slopes. Gulls and terns roost in mixed flocks along the open beaches, and unusual species such as Franklin's Gull, Glaucous Gull and Common Tern are usually associated only with these groups. Several species of shore-birds, including the endangered Piping Plover, can be seen feeding in the wet sand along the water line. Horned Larks (year-round) and several species of sparrows (winter) can be found foraging for seeds in the heavy grasses immediately behind the dunes. In the winter and during migrations, both Merlins and Peregrine Falcons perch on and along the beaches, waiting for an unsuspecting shorebird or migrant passerine to wander their direction.
Approximately 600 acres of park property were originally midgrass grassland of the seacoast bluestem - gulfdune paspalum series. Until purchased by TP&W for the creation of a state park, this grassland was heavily grazed by catle. After acquisition by TP&W, this disturbed prairie, left ungrazed and unburned, quickly began a succession to woody shrub. Baccharis (Baccharis halimifolia) and the exotic Chinese tallow (Sapium sebiferum) came to dominate these upland areas, and many of the grassland species of birds were replaced by those more typical of eastern woodlands. TP&W recently began a program to restore these critical coastal grasslands through cyclical mowing and burning. As these grasslands recover, many prairie-inhabiting birds will return to occupy this unique coastal habitat. For example, we should see birds such as Short-eared Owl, Sprague's Pipit and LeConte's Sparrow become increasing common in the winter. Bobolinks will hopefully appear again in late springs, and many of the grassland shorebirds (the endangered Eskimo Curlew, Long-billed Curlew, Upland Sandpiper and Buff-breasted Sandpiper) may be attracted to the shortgrass prairie created by late winter burning.
Before the arrival of European man, Galveston Island lacked significant tracts of native woodlands. Historical records indicate that woodland vegetation was limited to a few live oaks (Quercus virginiana) near the western tip of the island. The trees and shrubs in the park, therefore, have become established since and as a direct result of the arrival of European man. Species such as eastern live oak, Hercules club (Zanthoxylum clava-herculis), red mulberry (Morus rubra), wollybucket (Bumelia lanuginosa), sugar hackberry (Celtis laevigata) and gulf black willow (Salix nigra) are native to the Texas coast and their presence in the park, although a result of man's activities, should be considered natural. Exotic species, such as Chinese tallow, slash pine (Pinus elliottii), salt cedar (Tamarix gallica), Japanese honeysuckle (Lonicera japonica) and chinaberry (Melia azedarach) originated either as ornamentals cultivated around the homes of early homesteaders or as windbreaks planted for cattle. These exotics are decidedly anomalous and are being eradicated from the park as a part of the program to restore the native ecosystem. Baccharis, although a native woody shrub, is being reduced from its position of dominance in these disturbed grasslands to a relative abundance more in line with its natural occurrence. As a result of this prairie restoration program, woodland habitat within the park is being significantly decreased from that which existed in the park's previously disturbed state. Simultaneous with this reduction, however, is TPWD's expansion of the live oak mottes within the park to enhance the native woodland habitat available for neotropical migrants such as flycatchers, vireos and warblers. Substantial native woodlands will continue to exist in the park, therefore, and the overall diversity of bird species will increase as grassland and prairie species become reestablished.
In general, fresh water is restricted and its sources are ephemeral on a barrier island, and Galveston Island State Park is no exception. An impressive array of wetland birds, however, can be found in and around the few freshwater swales and ponds in the park. Many of these ponds and swales, particularly those immediately landward of the fore-island dunes, are lined with dense stands of common cattail (Typha domingensis) and common reed (Phragmites australis). This assemblage includes both the open waters of these ponds themselves, and the freshwater marshes which border them. Species such as Pied-billed Grebe, Least Bittern, Marsh Wren and Common Yellowthroat nest in the vegetation in and around these ponds. Several species of dabbling ducks winter in these shallow waters, and herons and egrets are always present feeding on the shores. Many migratory species of shorebirds only appear in the park to feed on the exposed mud around these ponds, and these birds are therefore more common in the park in years when a lack of rain has lowered freshwater levels. Also check the salt cedars around these ponds during spring and fall migration. Vireos, warblers, bunt-ings and orioles are attracted by the food and protection offered by these psuedo-riparian woodlands. During migrant groundings induced by inclement weather (particularly in the spring), these trees may appear to be festooned with the ornaments of a shattered avian rainbow.
Unlike the narrow stretch of sandy beach and low dune-fields on the seaward side of the island, the bay side is characterized by broad expanses of smooth cordgrass (Spartina alterniflora) marsh. Several sloughs and tidal bayous indent the bay margin, and these shallow tidal waters teem with a profusion of fishes and invertebrates. These wetlands are critical for the health of Galveston Bay. Juvenile fish and invertebrates are sheltered by the roots and stems of the grasses, and the marshes are a major source of detrital export for the bay system as a whole. The abundance of prey may attract hundreds of herons and egrets on a given day. Long-legged waders such as Roseate Spoonbill and White Ibis can best be seen in this habitat. The distribution of several salt-marsh specialists, such Clapper Rail and Seaside Sparrow, is restricted to these smooth cordgrass marshes. The muddy substrate exposed at low tide offers a rich feeding ground for many shorebirds such as Black-bellied Plover,Willet, Dunlin and Short-billed Dowitcher. Grebes, cormorants and loons are attracted by the fish that crowd the sloughs in winter. Even diving ducks such as Bufflehead, Ring-necked Duck and Hooded Merganser may at times venture into the deepest waters of Oak and Carancahua bayous during that season.
At ebb tide, particularly during winter "northerns" when the bay waters are at their lowest, vast areas of normally inundated mudflats and oyster reefs are exposed to feeding shorebirds, herons and egrets. The reefs may attract one or two American Oystercatchers, and an extreme low tide is ordinarily the only opportunity to see this rarity in or near the park. Reddish Egrets will often prey upon the fish left stranded by the receding tides, and Marbled Godwits, normally absent in the park, will wade through the shallow waters looking for bristle worms. A distinctive tidal flat vegetation has evolved upon the saline soils found immediately inland of the bay margins. Plants such as glasswort (Salicornia europaea), saltwort (Batis maritima), saltgrass (Distichlis spicata) and sea ox-eye daisy (Borrichia frutescens) predominate. Within this relatively sparse landscape nest several species of birds, such as Wilson's Plover, Willet, and Horned Lark. Long-billed Curlews and Whimbrels search these "salt flats" for for fiddler crabs, and roosting shorebirds, gulls and terns gather on the flats above the high tide line.
Like the waters of the Gulf of Mexico, many interesting waterbirds are limited in the park to the open waters of West Galveston Bay. Swimming and diving birds are most common in the bay because of the relative calmness and clarity of its waters. Brown Pelicans, once extirpated but their numbers now increasing annually, will dive for fish in the near-shore waters. Skeins of migrating ducks and geese are blown by "northerns" out over the bay in fall and winter. Large flocks (rafts) of Eared Grebes, at times numbering in the thousands of birds, will mass in the bay, and diving ducks such as Common Goldeneye and Lesser Scaup can be relatively common there in some years. The bay is the best location to find Magnificent Frigatebirds in late summer and early fall. Look for these huge birds roosting upon pilings out in the bay.
The only breeding colony for colonial waterbirds within the park is located near the observation tower at the end of the nature trail immediately north of Butterrowe Bayou. Great Blue Heron, Great Egret, Snow Egret, Tricolored Heron, Reddish Egret and Cattle Egret all nest in the rookery that has developed in the woody scrub at the end of the trail. Laughing Gulls prefer to nest on the ground in the marshhay or saltmeadow cordgrass (Spartina spartinae), and both Gull-billed Terns and Black Skimmers have bred on the shell and sand in the same general area. Forster's Terns breed in a colony located on Hoecker's Point (located outside of the park immediately to the northeast).
The development of the park itself created habitat for several species of birds. Rock Doves, Great-tailed Grackles and House Sparrows are attracted by the litter and garbage left by visitors. Drainage culverts provided nest sites for Barn Swallows. Purple Martins nest in houses erected specifically for that purpose. Killdeer and Common Nighthawks nest in small depressions (scrapes) in oyster shell and gravel roads in the park.
Although rarely landing, there are several species of birds that are typically seen only when they fly over or through the park. Except for the Barn Swallows breeding within the park in summer, migrating swallows feed on the wing and therefore rarely stop within the park's boundaries. Hawks are often viewed riding thermals (kettling) high overhead, and flocks of shorebirds can be seen in spring flying in from the Gulf of Mexico after incredible non-stop flights from Central and South America. Gulls and terns are forever crossing the park as they move between the gulf and bay. Barn Owls, the only resident owl within the park, are most often seen searching for prey as they hover over the open coastal grasslands at twilight.