Showing papers on "Nycticorax published in 1985"
TL;DR: Eight species of birds fed on a community of sticklebacks living in salt marsh pools along the southern shore of the St. Lawrence estuary in May and June when the fish breed, indicating selective predation is playing a role in structuring this fish community.
Abstract: Eight species of birds fed on a community of sticklebacks living in salt marsh pools along the southern shore of the St. Lawrence estuary in May and June when the fish breed. Three birds, the black-crowned night heron (Nycticorax nycticorax), the bronzed grackle (Quiscalus quiscula), and the ring-billed gull (Larus delawarensis) accounted for 80% of the estimated captures. Bird predation removed about 30% of the sticklebacks in the marsh. Significantly more male than female Gasterosteus aculeatus and G. wheatlandi were eaten, indicating selective predation is playing a role in structuring this fish community.
61 citations
01 Jan 1985
TL;DR: In a study of night-herons, egrets, and white-faced ibis nesting at Ruby Lake, Nevada as mentioned in this paper, the authors found that the most sensitive species to DDE-induced shell thinning were egrets.
Abstract: -The incidence of DDT (parent compound) declined significantly in the eggs of Blackcrowned Night-Herons (Nycticorax nycticorax), White-faced Ibis (Plegadis chihi), and Black-necked Stilts (Himantopus mexicanus), and showed a downward trend in Snowy Egrets (Egretta thula). Mean DDE residues (breakdown product of DDT) in eggs declined significantly in Black-crowned NightHerons and showed a downward trend in Black-necked Stilts and Snowy Egrets; however, no trend was apparent for White-faced Ibis. Some night-herons, egrets, and ibis laid thin-shelled eggs that cracked; eggshell thickness was negatively correlated with DDE residues in the egg contents. Ibis were the most sensitive species to DDE-induced shell thinning. Generally, reduced reproductive success for ibis started at lower DDE egg residues (3 ppm) than for either Snowy Egrets (5 ppm) or night-herons (8 ppm). Egg residue profiles, band recoveries, biotelemetry studies, and residues in fish and other prey items implicate the southwestern United States (a wintering area) as an important source of DDT-DDE that caused the most serious reproductive problem encountered during the study (in night-herons nesting at Ruby Lake, Nevada). Available evidence indicates that the three other species, together with night-herons from Oregon and Idaho, winter in Latin America.
34 citations
TL;DR: A survey of bird casualties resulting from collisions with cables in a section of the Margarita power transmission line at Chacopata Lagoon, northeastern Venezuela, where it runs between two expanses of water, was undertaken on 27 February 1983.
26 citations