Tag: all of Larus

Courtship feeding between Yellow-legged Gull Larus cachinnans and Herring Gull L. argentatus in the Western Mediterranean

Yellow-legged Gull (Larus cachinnans) Science Article 1 abstract Several species of large white-headed gulls, genus Larus, often hybridize freely where they occur sympatrically (Ingolfsson 1987, Pierotti 1987, Spear 1987, Pierotti & Annett 1993). In the Ebro Delta (Ebro Delta National Park, 40

Predation by a Marsh Harrier Circusaeruginosus on Yellow-legged GullLarus michahellis nests

Yellow-legged Gull (Larus cachinnans) Science Article 3 abstract This note reports a case of predation by an adult female Marsh Harrier Circus aeruginosus onthree nests of Yellow-legged Gulls Larus michahellis at the Ebro Delta. The predation wasobserved on 4 April 2002 on one of the dykes that separate the saltpan-heaters of La Trinitat(Punta de la […]

Deconstructing myths on large gulls and their impact onthreatened sympatric waterbirds

Yellow-legged Gull (Larus cachinnans) Science Article 2 abstract Owing to increasing population trends and facultative predatory habits, large gullshave been identified as significant agents of change in the alteration of manyecological communities. Often, they are perceived as negatively impacting thepopulation trends of most sympatric waterbirds. Consequently, culling programshave been implemented to remove adults, chicks and […]

Astaxanthin is responsible for the pink plumage flushin Franklin’s and Ring-billed gulls

Ring-billed Gull (Larus delawarensis) Science Article 3 abstract Carotenoid pigments produce the red, orange, and yellow plumage of many birds. Carotenoidcontainingfeathers are typically rich in color and displayed by all adult members of the species. In many gulls andterns, however, an unusual light pink coloring (or flush) to the normally white plumage can be found […]

Impact of the Ring-Billed Gull (Larus delawarensis) on the Microbiological Quality of Recreational Water

Ring-billed Gull (Larus delawarensis) Science Article 1 abstract We evaluated the impact of the ring-billed gull (Larus delawarensis) on the microbiological quality of water. We measured fecal coliforms, Salmonella spp., and aeromonas spp. in the gull droppings and the number of fecal coliforms in the water prior to and after attracting these birds to the […]

METABOLISM AND THERMOREGULATION IN HATCHLING WESTERN GULLS

Ring-billed Gull (Larus delawarensis) Science Article 9 abstract Parental attentiveness provides hatchlings of many precocial and serniprecocial birds with a large measure of protection from the vagaries of the thermal environment. Nonetheless some of these species differ in thermoregulatory capacity of newly hatched chicks, in correlation with climatic conditions during the breeding season. WILLIAM R. […]

Importance of migrating salmon smolt in Ring-Billed (Larus delawarensis) and California Gull (L. californicus) diets near Priest Rapids Dam, Washington

Ring-billed Gull (Larus delawarensis) Science Article 2 abstract Ring-billed (Larus delawarensis) and California Gulls (L. californicus) have been implicated in depredations on migrating salmon smolt in the Columbia River. As part of a gull management program conducted in 1995 and 1996, we collected L. delawarensis (n = 120) and L. californicus (n = 45) near […]

MIGRATION AND DISPERSAL IN GREAT LAKES RING-BILLED AND HERRING GULLS

Ring-billed Gull (Larus delawarensis) Science Article 10 abstract Band-recovery dam for Ring-billed (Larus delawarensis) and Herring (L. argen- tatus) Gulls were analyzed to determine the origins of gulls breeding within the Great Lakes region, the extent of lake and colony fidelity, and the winter and breeding season distributions of gulls of various age classes STEVEN […]

PURSUIT AND CAPTURE OF A RING-BILLED GULL BY BALD EAGLES

Ring-billed Gull (Larus delawarensis) Science Article 4 abstract Bald Eagles (Haliaeetus leucocephalus) are opportunistic hunters that employ a numberof techniques to capture a wide variety of prey (Bent 1937, Brown and Amadon 1968,Sherrod et al. 1976, McEwan and Hirth 1980). These eagles are known to occasionallypursue prey, including flying birds, in pairs or larger groups […]

Breeding success relative to nest location and density in Ring-billed Gull colonies.

Ring-billed Gull (Larus delawarensis) Science Article 6 abstract The role of nest location and density in determining breeding success in Ring-billed Gulls (Lams delawarensis), to our knowledge, has not been studied previously. In breeding colonies some nests will be located centrally while others are peripheral. WILLIAM E. SOUTHERN, THE WILSON BULLETIN Vol. 86, No. 3 […]