Most nesting occurs from April to June, but in 

 Louisiana, nesting may occur all year. Oberholser 

 (1974) confirmed that nesting occurs in the Chenier 

 Plain of Texas. Mourning doves may make four to six 

 attempts at nesting but only two or three of these may 

 be successful (Lowery 1974a, Sanderson 1977). Any 

 available tree is used for nesting (St. Amant 1959). 

 Nesting habitat includes woodland edges, shelterbelts, 

 church and cemetary sites, cities, farmlands, and 

 orchards. Nests are flimsy platforms that hold two eggs 

 (Sanderson 1977). Incubation lasts 14 days. 



Pasture and rice lands in southwestern Louisiana 

 produce excellent dove food. Intensive agriculture 

 sometimes may have a detrimental effect on mourning 

 dove populations (Sanderson 1977). In Texas, a decline 

 in the number of doves has been attributed to drought 

 and trichomoniasis (Oberholser 1 974). 



5.3.33 BARN OWL {Tyto alba) 



Barn owls reside in the Chenier Plain throughout 

 the year. Young birds disperse over a wide area in re- 

 sponse to food shortages (Sparks and Soper 1970). 

 Barn owls become active and reportedly fly many miles 

 while hunting during the night (Presst and Wagstaffe 

 1973). They return to roost before sunrise (Karalus and 

 Eckert 1974). Aduhs usually nest in late winter and 

 late summer, producing two broods per year (Karalus 

 and Eckert 1974). 



Barn owls flourish in warm, open or semi-open 

 lowlands such as prairies, meadows, marshes, and sea- 

 shores (Oberholser 1974), often in proximity to man. 

 They usually nest or roost in isolated structures such as 

 old buildings or in clumps of trees (Karalus and Eckert 

 1974). 



Bam owls eat mice, rats, shrews, rabbits, and birds, 

 especially European starlings and house sparrows 

 (Oberholser 1974). Mice make up more than half of 

 their diet (Karalus and Eckert 1974). Frogs, snakes, 

 lizards, fishes, crayfish and insects also are eaten. 



Bam owls require appropriate structures in which 

 to nest. These include isolated buildings and hollow 

 trees. When these structures are not available, barn 

 owls will nest in abandoned crow or hawk nests, or even 

 occasionally in holes in the ground. Nests usually con- 

 tain 3 to 7 eggs, but up to 14 have been found. Both 

 parents incubate the eggs. Incubation begins after the 

 first egg is laid and lasts approximately 33 days. The 

 young hatch on different days, and the oldest have an 

 advantage in obtaining food from the parents (Karalus 

 and Eckert 1974, Oberholser 1974). 



Survival of the young barn owls depends upon 

 available food supply (Karalus and Eckert 1974). Fre- 

 quently barn owl abundance corresponds with cyclic 

 abundance of rodents (Sparks and Soper 1970). Use of 

 agricultural chemicals may be a factor in the decline of 

 barn owls in agricultural areas. 



5.3.34 COMMON SCREECH OWL (Otus asio) 



Screech owls are nocturnal predators and have 

 been known to range at least 1.6 km (1 mi) to feed. 

 They inhabit open woodlands, especially those adja- 

 cent to grain fields, meadows, and marshes. They of- 

 ten roost in tree cavities (Karalus and Eckert 1974). 

 Screech owls may also be found in young second- 

 growth forests or in scrub forests. 



Screech owls eat rodents, amphibians, reptiles, 

 small birds, and insects. Small birds are consumed in 

 largest quantities during the nesting period (Karalus 

 and Eckert 1974). This owl requires hardwood tree 

 cavities for nesting and in the Chenier Plain, the removal 

 of hardwood stands has probably greatly reduced 

 the abundance of this species. 



5.3.35 GREAT HORNED OWL {Bubo virginianus) 



Great homed owls are year-round residents of the 

 Chenier Plain. Although primarily nocturnal, they are 

 sometimes active on overcast days. The species appa- 

 rently maintains the same range throughout the year. 

 Craighead and Craighead (1956) found an average of 

 one pair of birds for each 16 km^ (6 mi^) in Michigan. 



Great horned owls occur primarily in areas of 

 hardwood trees intermingled with fields and marshes. 

 In the Chenier Plain, it occurs regularly in the chenier 

 forests (Karalus and Eckert 1974). It consumes large 

 quantities of mammals, especially rabbits, skunks, rats, 

 and mice (Lowery 1974a). They may also prey on 

 other owls (Karalus and Eckert 1974). 



Great horned owls require hollow trees or other 

 appropriate structures, such as abandoned crow or 

 eagle nests, for nesting purposes. Habitat loss is a major 

 factor in the reduction of this species. 



5.3.36 CANADA GOOSE (Branta canadensis) 



The Canada goose was once abundant on the 

 Chenier Plain where wintering populations numbered 

 over 100,000 birds (Singleton 1953, Belsom 1974). 

 Wintering populations began a rapid decline during the 

 late 1940's, and by the eady 1950's, they numbered 

 less than 15,000 (Singleton 1953, Smith 1961, 

 Belsome 1974). Now only a few thousand birds over- 

 winter in the Chenier Plain. 



Migrant Canada geese usually arrive in the Chenier 

 Plain in eariy October and small groups continue to 

 arrive throughout the fall and winter with peak 

 numbers present in January. Canada geese migrate 

 from the Chenier Plain in the spring to a vast breeding 

 area extending from the midwestern states to the 

 southern edge of Hudson Bay. Paired birds remain 

 together for life. The male stands guard while the 

 female incubates the eggs (Bellrose 1974). 



In the Chenier Plain the Canada goose is found 

 predominantly in the rice fields and pastures. This 

 species uses upland sites more than do other waterfowl. 



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