SEASONAL ABUNDANCE 
J FMRMJ J RSOND 
I I 1 I I I I I I I I I 
PHYTOPLHNKTON 
ZOOPLANKTON ° 
BENTHOS 
COLONIAL 
NESTING BIRDS 
SHORE BIRDS 
WATERFOWL 
LOW i n i n 
MEDIUM 
HIGH 
Figure 2.1. Seasonality of the components of the benthic food iveb in relation to the abundance of Galveston Bay avifauna 
(1,17,33,34,35,36,64). 
ing shorebirds utilize intertidal flats on Bolivar Peninsula and on the east and west ends of Galveston 
Island. Of the 35 species of shorebirds reported for Galveston Bay (Table 2.8), the most common forms 
are Pluvialis squatarola (black-bellied plover), Recurvirostra americana (American avocet), Ca- 
toptrophorus semipalmatus (willet), Calidris alba (sanderling), Calidris mauri (western 
sandpiper), Calidris alpina (dunlin), and Limnodromus spp. (dowitchers) (64). Peaks in shorebird 
utilization of Galveston Bay occur during the winter months through spring migration (December 
through May). Chronology of migration and intertidal flat use may be tied to macrobenthic prey 
phenology (Figure 2.1). Six species of shorebirds are known to nest in the bay complex: Charadrius 
wilsonia (Wilson's plover), Charadrius vociferus (killdeer), Haematopus palliatus (American 
oystercatcher), Himantopus mexicanus (black-necked stilt), willet and American avocet. 
Surveys of colonial nesting waterbirds in the Galveston Bay system have been conducted since 
1967 (33,35). During the period 1973 through 1987 (Figure 2.2), numbers of pairs of colonial nesting 
waterbirds varied from lows of approximately 39,000 in 1978 and 1985 to a high of 71,700 in 1982 with 
a mean of 52,136 (33). Active colony numbers have increased from 20 in 1973 to 42 in 1987. Colony 
sites include gravel and shell bars, Spartina alterniflora marshes, cypress stands, dredged material 
islands, and industrial and developed locations. Twenty-two species of colonial nesting waterbirds 
have been reported as nesting during the 21 years of surveys (Table 2.9). The three most common 
species during the 1986 nesting season were Larus atricilla (laughing gull). Sterna maxima (royal 
tern) and Bubulcus ibis (cattle egret) (36). 
Birds that have been identified as threatened or endangered by the U.S. Fish and Wildlife Service 
(33) include Pelecanus occidentalis (brown pelican), Charadrius melodus (piping plover), Nume- 
nius borealis (eskimo curlew). Sterna antillarum (interior least tern), Haliaeetus leucocephalus 
(bald eagle), Falco peregrinus (peregrine falcon), and Mycteria americana (wood stork). 
Amphibians and Reptiles—Ninety-two species of amphibians and reptiles have been reported 
for the four counties surrounding Galveston Bay (37). Mueller (38) described only 15 species of 
amphibians and reptiles from nontidal wetlands on Galveston Island, however. The American 
35 
