|Statement||Roger M. Evans.|
|Series||Animal behaviour monographs / editors J.M. Cullen, G.C. Beer -- vol.3, pt.3, Animal behaviour monographs -- vol.3, pt.3.|
|Contributions||Cullen, J. M., Beer, Colin.|
Imprinting and Mobility in Young Ring-Billed Gulls, Larus delawarensis [R.M. EVANS] on *FREE* shipping on qualifying offers. Imprinting and Mobility in Young Ring-Billed Gulls, Larus delawarensis, , Animal Behaviour Monographs, Volume 3, Part 3: pages with 8 figures and 24 tables. [R. M. Evans] on *FREE* shipping on qualifying : R. M. Evans. Ring-billed Gull cm; g; wingspan cm. Three-year gull. The breeding adult has a white head, body and tail, pale grey mantle and upperwings; black outer. Young were exposed to the call of an adult ring-billed gull (Larus delawarensis) paired with a visual imprinting stimulus (S +).This exposure was alternated with one of three (S −) conditions; a call from a different conspecific adult, silent periods, or a call from a different visually associated call and the second conspecific call were then used for auditory discrimination by: 9.
Ring-billed Gull (Larus delawarensis) Adults and Fledglings - Niagara Falls New York - J Ring-billed gulls are medium-sized birds. Males are slightly larger than females. They are about cm long and weigh about g. Females are about cm long and weigh about g. Males and females have a wingspan of about cm. The backs and shoulders of ring-billed gulls are pale bluish-gray, and the head is white. Ring-billed Gull delawarensis 1st PB moult, July 17 , Daytona Beach, FL. (Tore Grebberg). Ring-billed Gull delawarensis 2nd cycle, October 27 , Dallas, TX. (Wikipedia Commons). Ring-billed Gull delawarensis 2nd cycle, January 03 , Seward Park, Seattle (Amar Ayyash). Variation in Juvenile Ring-billed Gulls (Part 1) Juvenile Ring-billed Gulls (Larus delawarensis) are quite distinctive within their range, but anyone who's ever spent a little time observing this age group quickly comes to the realization that characterizing a "typical" youngster is no simple task.
The Ring-billed Gull is probably the most common gull found in the state. Adapted well to living with humans, it can often be found sitting in parking lots or scavenging at landfills. The yellow legs and overall size help to distinguish the species from other similarly plumaged gulls found in the state, as does the characteristic black ring. Gulls are often the most abundant and visible coastal birds, regardless of the season. This is largely because they are remarkably successful at adapting to different environments and are opportunistic feeders. In the winter, ring-billed gulls (Larus delawarensis) are one of the most common gulls in Massachusetts, perhaps even outnumbering Herring gulls and Black-backed . Click here for more information about the Red List categories and criteria Justification of Red List category This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence. While the breeding ecology of gulls (Laridae) has been well studied, their movements and spatial organization during the non-breeding season is poorly understood. The seasonal movements, winter-site fidelity, and site persistence of Ring-billed (Larus delawarensis) and Herring (L. argentatus) gulls to wintering areas were studied from –Cited by: 5.