winter resident in the Chenier Plain. It is present in 

 highest numbers from October to May. Birds nest 

 singly, but several individuals may nest in the same 

 vicinity. Nests and roosts are near feeding areas and 

 daily movements are not extensive. 



The American bittern is found principally in fresh 

 marsh habitat, but it sometimes is found in fields of 

 tall grass (Palmer 1962). In the Chenier Plain, it is also 

 regularly found in the brackish marsh habitat. 



American bitterns consume a variety of foods. 

 A survey of 133 stomachs by U.S. Biological Survey 

 found 20% fish (primarily noncommercial), 19% cray- 

 fish, 23% insects, 21% amphibians, 10% mice and 

 shrews, 5% snakes, and 2% miscellaneous inverte- 

 brates. 



The American bittern is not known to nest in the 

 Chenier Plain. 



5.3.15 WOOD STORK (Mycteria americana) 



Wood storks migrate into the Chenier Plain after 

 nesting elsewhere, principally in southern Florida. 

 Many stay throughout the summer; others only pass 

 through. Wood storks are present from March through 

 November with maximum numbers from June through 

 September (Lowery 1974a). They feed and rest in 

 groups. Individuals often rest in trees for hours. They 

 soar overhead in large circles, commonly between 9 

 a.m. and 3 p.m. They fly at least 15 to 25 km (9.3 to 

 15.5 mi) from roosting to feeding areas (Palmer 1962). 



Wood storks are primarily freshwater residents. 

 They feed in prairie ponds, swamp forests, flooded pas- 

 tures, inundated fallow fields, borrow ditches, and the 

 shallow shorelines of rock pits. An ebb tide or falling 

 water level is preferred for feeding (Palmer 1962). 



A variety of foods is consumed, including min- 

 nows, crustaceans, mollusks, reptiles (young alligators, 

 snakes, small turtles), tadpoles and frogs, small mam- 

 mals, insects, plants, and seeds (Palmer 1962). 



The draining of marshes and drought, fire, 

 lumbering, and land clearing has caused severe popula- 

 tion declines of wood storks in gome areas of the U.S. 



5.3.16 WHITE-FACED IBIS (Plegadis chihi) 



The white-faced ibis is a permanent resident of the 

 rice fields and coastal marshes of the Chenier Plain. 

 DaOy movements consist of flocks of this rather no- 

 madic feeder flying between feeding and resting or 

 nesting areas. Each parent makes six or more trips per 

 day to feed young (Palmer 1962). The species often 

 occurs in large flocks and flies in a characteristic "V" 

 formation. Individuals alternately flap and glide in 

 flight. The white-faced ibis is spreading its range east- 

 ward from Texas; it has apparently occupied the 

 former range of the glossy ibis {P. falcinellus). 



Palmisano (1971) found few white-faced ibises in 

 fresh marshes, but none in the salt marshes in south- 

 western Louisiana. Sometimes it also is found in rice 

 fields and pastures (Lowery 1 974a). 



This ibis feeds by probing with its bill. Important 

 foods include crayfish and insect larvae (Belknap 1957). 



Less than 1% of the Louisiana white-faced ibis 

 nest in the Chenier Plain (Portnoy 1977), although 

 Palmer (1962) indicates that this area could be the cen- 

 ter of abundance. Belknap (1957) reported that the 

 species nests near the ground in reed and buttonbush 

 growth in association with other wading birds. Portnoy 

 (1977) also found them nesting in black mangroves. In 

 mixed colonies that are associated with short vegeta- 

 tion, this species tended to nest on the ground (Burger 

 1978). The white-faced ibis normally begins nesting in 

 May. 



A die-off of white-faced ibis in the Texas Chenier 

 Plain in 1974 was reported to be due to eggshell thin- 

 ning caused by excessive concentrations of DDE, diel- 

 drin, and aldrin. Its very specific nesting behavior 

 makes this species particularly vulnerable to human dis- 

 turbance and wefland loss (Burger and Miller 1977). 



5.3.17 WHITE IBIS (Eudocimm albus) 



The white ibis is common in the Chenier Plain 

 from late March to late September. Some individuals 

 overwinter. Daily movements consist of flights to and 

 from feeding areas and resting or nesting areas. Large 

 flocks flying to and from feeding areas are common. 

 Birds may fly over distances of 100 km (62 mi) (Palmi- 

 sano 1971). 



The white ibis is abundant in coastal marshes and 

 freshwater swamps and is primarily a nonvisual, tactile 

 forager (Kushlan 1977). Foods include worms, insects, 

 crustaceans, arthropods, mollusks, fish, amphibians, 

 and reptOes. 



The white ibis nests in colonies, often in associa- 

 tion with other species. Nests are constructed in trees 

 or shrubs, or on the ground. Portnoy (1977) found few 

 nests of this species in the Chenier Plain. 



There have been recent pesticide-related die-offs in 

 Texas and similar die-offs may also be occurring in Lou- 

 isiana. 



5.3.18 ROSEATE SPOONBILL (Ajaia ajaja) 



The roseate spoonbill is a year-round resident. Its 

 northernmost distribution is in Louisiana, where it 

 nests exclusively in the Chenier Plain (Palmer 1962). In 

 Texas, the species nests along the coast from the Che- 

 nier Plain southward. As with other waders, daily 

 movements consist primarily of flights between resting 

 or nesting areas and feeding areas. Neither the pattern 

 nor the length of these flights is known. 



Roseate spoonbills feed primarily in open areas, 

 but they nest and roost in woody vegetation. In the 

 Chenier Plain, they are most abundant in fresh marsh 

 habitat, but occasionally inhabit brackish and salt 

 marshes and pastures. This species feeds by sweeping 

 the bill sideways through the water. The diet is com- 

 posed primarOy of small fishes, but crustaceans, insects, 

 and mollusks are also eaten (Palmer 1962). 



235 



