http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
African Cattle egret in Texas and its relation to the Little blue heron, Snowy egret, and Louisiana heron
2 volumes (xxvi, 552 leaves) : illustrations, maps ; 29 cm
This study includes: 1) arrival, range expansion, seasonal distribution, and migration; 2) nesting habitats; 3) food habits; 4) reproduction; 5) population dynamics; 6) pesticide residues; 7) species interrelations; and 8) economic importance. Cattle Egrets first nested in Texas in 1959. Present breeding populations use 49.8% of Texas heronries occurring within their breeding range. Breeding populations include 34.3% in coastal zones, 33.3% in the Trinity River System, and 27.2% in the Sabine, Neches, Brazos, and Red River systems combined. Heronries occupied by the three associated species determine Cattle Egret breeding distribution. Cattle Egrets are the last species to arrive in Texas heronries. Post-breeding juvenile Cattle Egrets in Texas disperse southward and southwestward. Fall migration is gradual, coastward, mainly along flood plains, then southward as far as El Salvador. Cattle Egrets may have entered Texas from eastern Gulf States rather than Central America and Mexico. Inland heronries contain Cattle Egrets and Little Blue Herons, primarily. On coastal islands, Snowy Egrets and Louisiana Herons usually outnumber Cattle Egrets; Little Blue Herons are usually absent. Nest placement is relatively uniform and approximately unilayered. Cattle Egret late-nesting in Texas heronries synchronizes with accumulative increase of pasture-dwelling insects. Nest sites, materials, and construction resemble those of the three associated native ardeids, but Cattle Egrets exhibit less nest-site preference. Cattle Egret clutches average 3.58; average intervals and periods are: between successive eggs (2.04 days), incubation (24.0 days), and hatching (1.7 days). Cattle Egret chicks show sigmoidal growth pattern curves fitting the logistic equation. Few chicks starve. Heronry breeding successes, high to low, are: coastal islands, inland wooded islands, swamps, and woodlands. Estimated annual productivity for Cattle Egrets and Snowy Egrets is 1.2, for Louisiana Herons 0.9, and for Little Blue Herons 0.8...
"Major subject: Wildlife and Fisheries Sciences."
Includes bibliographical references (leaves 487-510).