The great blue heron is the largest wading bird that 

 resides in the Chenier Plain. It utilizes a variety of habi- 

 tats, including shallow water of ponds, lakes, marshes, 

 streams, and bays (Palmer 1962). 



Long legs and a large bill enable the great blue 

 heron to feed in deeper water and on larger food items 

 than most other wading birds. Food from 189 heron 

 stomachs collected in the United States consisted of 

 nonsport fish (43%), sport and commercial fish (25%), 

 unidentified fish (4%), aquatic insects (8%), crustace- 

 ans (9%), amphibians and reptiles (5%), mice and 

 shrews (5%), and other matter (2%) (Palmer 1962). In 

 Southern Louisiana, their diet included 67% fish, 10% 

 shrimp and crabs, and 5% small mammals (Day et al. 

 1973). Parents regurgitate food material for nestlings. 

 Feeding may occur up to 10 times per day during the 

 first week, and decrease to 4 times per day during the 

 fledgling period (Pratt 1970). 



Pesticide contamination in California and Iowa has 

 caused nesting failure (Konermann et al. 1978). Pratt 

 (1977) found that great blue herons sometimes were 

 preyed upon while nests were untended. Human 

 activity near nesting colonies has reduced nesting 

 success (Wersclikul et al 1976, English 1978). 



5.3.4 GREEN HERON (Butorides virescens) 



Although green herons are common in the Chenier 

 Plain during spring, summer, and fall, few remain 

 throughout the winter. They are most abundant from 

 mid-March to mid-November (Lowery 1974a). Green 

 herons nest singly or in small colonies near suitable 

 feeding areas, and do not fly far to feed. 



Green herons usually nest in woody vegetation 

 near open water. They nest and feed in both fresh and 

 salt marshes and along margins of streams. 



Green herons usually wait, often perched on an 

 overhanging branch or along a stream bank, for prey to 

 approach. Most food is obtained near the surface of the 

 water. Palmer (1962) found that their diet included 

 fishes (45%), crustaceans (21%), insects (24%), and 

 other small organisms. 



Green herons usually nest solitarily (Palmer 1962). 

 A few individuals may nest at the edges of large heron- 

 ries composed of other species. Initial clutch size 

 varies from 3 to 6 eggs, but second clutches usually are 

 smaller. Incubation lasts approximately 20 days, with 

 both parents participating. Young are fed 2 to 3 times 

 a day and become independent at about 30 to 35 days 

 (Palmer 1962). 



Further loss of swamp forest in the Chenier Plain 

 would reduce green heron populations. 



5.3.5 LITTLE BLUE HERON {Florida caerulea) 



The little blue heron nests in the Chenier Plain 

 area and is abundant from mid-March to mid-October 

 (Lowery 1974a). Post-nesting dispersal from the colony 



is common (Palmer 1962, Byrd 1978). Daily move- 

 ments consist primarily of flints to and from nesting, 

 resting, or feeding areas. During the breeding season, in 

 North Carolina, daily flights may be as far as 15 km 

 (9.3 mi)(Parnell and Soots 1978). 



In Texas and Louisiana, small numbers of little 

 blue herons feed and nest along bays and estuaries, but 

 densities are highest in fresh marsh habitat. Ninety- 

 seven percent of the nests in coastal Louisiana are loca- 

 ted in fresh marshes (Portnoy 1977). Less than 1% of 

 these nests occur in the Chenier Plain. In rice field 

 areas, this species frequents levees in search of food 

 (Palmer 1962). 



Little blue herons feed in shallow water along 

 shorelines. They stand motionless or move very slowly 

 and capture prey by a rapid thrust of the bill (Palmer 

 1962). They often feed in more densely vegetated areas 

 than other herons. In one study, of 46 stomachs ex- 

 amined, 45% contained crustaceans, 27% fish, 17% 

 insects, and 9% frogs, snakes, and turtles (Palmer 

 1962). 



Little blue herons usually nest in swamp forests, 

 often in close association with snowy egrets. Nests are 

 usually clumped in relatively tall vegetation. The spe- 

 cies will nest on herbaceous vegetation if woody spe- 

 cies are unavailable. Little blue herons nest earlier in 

 salt marshes than in fresh marshes (Portnoy 1977). 

 Renesting sometimes occurs. Incubation usually begins 

 after the second egg is laid (Maxwell and Kale 1977). 



Suitable nesting sites may be limited in some areas 

 because of competition with the cattle egret (Hilde- 

 brand and Blacklock 1969). In Alabama, eggshell 

 thickness was correlated with concentrations of both 

 DDE and dieldren in the eggs (Biskup et al. 1977). 

 Thin-shelled eggs are more easily broken by the setting 

 parent, thus limiting the number of young herons 

 which survive. 



5.3.6 CATTLE EGRET (Bulbulcus ibis) 



The cattle egret is primarily a summer resident in 

 the Chenier Plain, but increasing numbers of birds are 

 wintering there. Daily movements consist of flights 

 from roosting or nesting areas to nearby feeding areas. 



Cattle egrets often feed in association with cattle. 

 These birds feed primarily on insects, land snails, 

 earthworms, ticks, spiders, frogs, toads, snakes, and liz- 

 ards. 



Cattle egrets frequent more terrestrial habitat than 

 do other herons, but nest most commonly in fresh 

 marshes, to a lesser extent in salt marshes. They often 

 nest later than other herons in mixed-species colonies 

 (Jenni 1969). At Miller's Lake, Evangeline Parish, peak 

 nesting is mid-July (Ortego et al. 1976). Clutch size 

 averaged 3.5 in Florida (Jenni 1969). Because incuba- 

 tion begins at the onset of laying, hatching of the 

 young is staggered. The smallest nestlings sometimes 

 starve. Nestlings fledge at about 50 days of age (Palmer 

 1962). 



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