Contents
Gonadal Development during Autumn and Winter in House Sparrows
Robert E. Hegner and John C. Wingfield
Blood Constituents and Their Relation to Diet in Urban and Rural House Sparrows
Ann P. Gavett and James S. Wakeley
Incubation Rhythms of Ring-necked Ducks
William L. Hohman
Attendants at Tree Swallow Nests. I. Are Attendants Helpers at the Nest?
Michael P. Lombardo
Seabird Interactions with Dolphins and Tuna in the Eastern Tropical Pacific
David W. Au and Robert L. Pitman
Scavenging Efficiency of Turkey Vultures in Tropical Forest
David C. Houston
Manx Shearwater Chicks; Seasonal, Parental, and Genetic Influences on the Chick's Age and Weight at Fledging
M. De Brooke
Breeding Biology of Least Auklets on the Pribilof Islands, Alaska
Daniel D. Roby and Karen L. Brink
Sooty Shearwaters Off California; Distribution, Abundance and Habit Use
Kenneth T. Briggs and Ellen W. Chu
Directionality of Avian Vocalizations; a Laboratory Study
Malcolm L. Hunter, Alejandro Kacenik, John Roberts, and Maxime Vuillermoz
Book Reviews
March F. Lawton
Books Received
The Condor
News and Notes
The Condor
Who Was Cooper"?"
Howard L. Cogswell
Covers
Back Matter (PDF)
The Condor
Front Matter (PDF)
The Condor
Short Communications
Influence of Prey Distribution on Aggression in Ruddy Turnstones
Kimberly A. Sullivan
Cassin's Finch Nesting in Big Sagebreush
Siobhan L. Sullivan, William H. Pyle, and Steven G. Herman
Egg Production in Hand-raised White-crowned Sparrows
Luis F. Baptista and Lewis Petrinovich
Polygyny in the Willow Flycatcher
David R. Prescott
Effect of Mating Status and Time of Day on Kirtland's Warbler Song Rates
Jack P. Hayes, John R. Probst, and Don Rakstad
Changes in Water-vapor Conductance of Common Canary Eggs during the Incubation Period
Michael D. Kern
Reevaluation of Cheek Patterns of Juvenal-plumaged Blue-eyed and King Shags
Pamela C. Rasmussen
Flower Eating by Emerald Toucanets in Costa Rica
Cecilia M. Riley and Kimberly G. Smith
Speed of Flapping Flight of Merlins and Peregrine Falcons
William W. Cochran and Roger D. Applegate
Observations on the Behavior and Ecology of the Mariana Crow
Diana F. Tomback