5.3.26 LAUGHING GULL (Lams atricilla) 



Laughing gulls are more abundant in summer than 

 winter in the Chenier Plain. They are most abundant in 

 nearshore Gulf waters, along beaches, and in salt 

 marshes. They nest in colonies that usually are located 

 in smooth cordgrass or on barrier island beaches (Por- 

 tnoy 1977). Nests are usually in isolated locat'ois. 

 Laughing gulls usually feed in shallow water, but may 

 feed in open water or scavenge on land. Large numbers 

 of gulls often follow fishing boats. Groups often roost 

 on sand spits at low tide. 



Laughing gulls eat a large variety of animal matter 

 obtained on or near the water surface Oberholser 

 (1974) reported that crabs, small fishes, and shrimp are 

 important food items and stated that there is a prefer- 

 ence for foods containing a relatively large proportion 

 of fat or animal oils. This species does not frequent gar- 

 bage dumps as much as do other gulls. This species 

 occasionally consumes eggs or young of other birds 

 nesting nearby. 



Laughing gulls usually use sticks or grass for 

 nesting material, but sometimes will merely scrape a 

 depression in sand or shell substrates. Nests are usually 

 concealed among low, dense shrubs or clumps of grass. 

 The nesting season extends from April to August and 

 peaks in mid-May (Portnoy 1977). Hildebrand and 

 Blacklock (1975) stated that mortality of young is 

 always high, sometimes close to 100%. 



Suitable nesting locations are rare in the Chenier 

 Plain. Traditional nesting sites should be protected if 

 possible. At Brigantine National Wildlife Refuge, New 

 Jersey, Montevecchi (1977) found that eggs of I'augh- 

 mg gulls were preyed upon by fish crows {Corvus ossi- 

 fragus), common crows (Corvus brachyrynchos). and 

 herring gulls {Lams argentatus). Herring gulls also 

 preyed on laughing gull chicks. Barn owls (Tyto alba). 

 great horned owls (Bubo virginianus), and marsh hawks 

 (Circus cyaneus) were also responsible for chick and 

 adult mortality. 



5.3.27 FORSTER'S TERN (Sterna forsteri) 



Forster's terns are primarily a migratory species, 

 but there are some individuals present all year, especial- 

 ly on the coast. This species breeds and nests in colo- 

 nies. Individuals move unknown distances from the 

 colonies to feed. 



Forster's terns often nest in small groups on sandy, 

 open beaches, lagoons, and inlets. They seem to fre- 

 quent all marsh types, but usually nest in salt marshes 

 (Portnoy 1977). Colonies are usually located where the 

 marshes contain a large number of open-water pools. 

 They usually nest in the open, either on or adjacent to 

 the tidal wrack. They feed by diving into the water 

 and catching fish near the surface. Foraging areas need 

 to be productive, and the water should be clear enough 

 for the terns to see their prey. 



Forster's terns feed primarOy on small fish, but 

 also eat other small aquatic animals near the water sur- 

 face (Oberholser 1974). This species frequently eats 

 aquatic insects, and sometimes flying insects. 



Forsters' terns usually nest in colonies on islands 

 in a marsh. Nests usually are located on driftage or 

 other firm substrates where marsh vegetation is absent. 

 Nests are sometimes placed on muskrat houses. The 

 majority (63%) of the nests found by Portnoy (1977j 

 were in salt marshes; 35% were found in brackish 

 marshes; and only 1.1% in fresh marshes. Only 0.5% of 

 the nests were found on coastal beach and 0.8% on 

 spoil islands. This species nests earlier than other water- 

 birds in Louisiana (Portnoy 1977). Most nesting occurs 

 between March and July. 



A shortage of suitable isolated nesting sites may 

 limit the distribution of this species. Portnoy (1977) 

 reported one colony of 2,750 incubating adults which 

 abandoned their nests after some of its members were 

 shot. Because of this bird's position in the food web, 

 they may occasionally accumulate excessive concentra- 

 tions of contaminants. 



5.3.28 LEAST TERN (Sterna albifrons) 



The least tern is primarily a summer resident that 

 migrates to the Chenier Plain in late March or early 

 April and remains until late October. There are a few 

 scattered winter coastal records of birds (Lowery 

 1974a). In the Chenier Plain, least terns usually nest in 

 proximity to feeding areas, and daily movements there- 

 fore are not extensive. 



Least terns require a flat, essentially bare area for 

 nesting, and open, shallow water nearby for feeding 

 (Portnoy 1977). This species is distributed primarily 

 along the coast (Oberholser 1974), but it also occurs 

 along large open bodies of water such as bays, estuaries, 

 and major rivers. 



Most food is obtained in shallow water (Ober- 

 holser 1974). and consists primarily of small fishes 

 caught by skimming the surface or diving (Bent 1921). 



Least terns nest largely on sandy beaches close to 

 civilization (Oberholser 1974). In Texas (Hildebrand 

 and Blacklock 1969) and Louisiana (Portnoy 1977), it 

 commonly nests on newly formed dredged-material 

 islands. This species usually does not nest in colonies 

 with other waterbirds (Oberholser 1974). Four of the 

 five colonies Portnoy (1977) found in the Chenier 

 Plain were on a beach and one was on spoil. Eighty-five 

 percent of the nests were near salt water, often on 

 sand. Incubation peaked in early May (Portnoy 1977). 



In the past, populations of least terns were deci- 

 mated by market hunters. Collected specimens were 

 used primarily as decorations. The protected status of 

 this species has allowed its numbers to increase. Histo- 

 rically, least terns nested on sandy beaches. Proximity 

 to occasional activities of man is no great hindrance. If 

 refuges are established on a beach, this species can nest 

 successfully. (There is such a refuge near Biloxi, Missis- 

 sippi.) Exceptionally high tides also can wash away 

 beach nests. This species will use fresh spoil areas for 

 nesting; however, plant succession soon makes spoil 

 areas unsuitable. 



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