Contents
Nannopsittaca Dachilleae, a New Species of Parrotlet from Eastern Peru
John P. O'Neill, Charles A. Munn, and Irma Franke J.
Ecogeographic Variation in the American Robin (turdus Migratorius)
John W. Aldrich and Frances C. James
Food of Juvenile Common Eiders (somateria Mollissima) in Areas of High and Low Salinity
K. G. Kenneth Nystr
A Miniature Activity Recorder for Plunge-diving Seabirds
David J. Anderson, Paul R. Sievert, John Andrews-Labenski, and Robert E. Ricklefs
Dispersion Patterns and Habitat Associations of Rufous-sided Towhees, Common Yellowthroats, and Prairie Warblers in the Southeastern Massachusetts Pine Barrens
David C. Morimoto and Fred E. Wasserman
Clutch Size and Reproductive Success of House Wrens Rearing Natural and Manipulated Broods
Kathryn D. Robinson and John T. Rotenberry
Green Woodhoopoes (phoeniculus Purpureus) and Obligate Cavity Roosting Provide a Test of the Thermoregulatory Insufficiency Hypothesis
Joseph B. Williams
Influence of Site Fidelity on Mate Switching in Urban-breeding Merlins (falco Columbarius)
Ian G. Warkentin, Paul C. James, and Lynn W. Oliphant
Foraging Ecology of Nuttall's Woodpecker
William M. Block
Notes and News
The Auk
Interspecific Allozyme Differentiation among North Atlantic White-headed Larid Gulls
Richard R. Snell
Winter Weather, Spring and Summer Density, and Subsequent Breeding Success of Eurasian Kestrels, Common Buzzards, and Northern Goshawks
Renate Kostrzewa and Achim Kostrzewa
Rejection Behavior by Common Cuckoo Hosts towards Artificial Brood Parasite Eggs
Arne Moksnes and Eivin R
Food Patches and the Spacing of Individual Foragers
Scott M. Pearson
100 Years Ago in the Auk
The Auk
Growth and Brood Reduction of Mid-atlantic Coast Ospreys
Robert J. Steidl and Curtice R. Griffin
Female Condition and Delayed Benefits to Males that Provide Parental Care: a Removal Study
Licia Wolf, Ellen D. Ketterson, and Val Nolan Jr.
Sequestered Paralytic Shellfish Poisoning Toxins Mediate Glaucous-winged Gull Predation on Bivalve Prey
Rikk G. Kvitek
Sexual Differences in Parental Effort during the Nestling Period in Tree Swallows (tachycineta Bicolor)
Michael P. Lombardo
Nest-site Selection and Nesting Success of Cavity-nesting Birds in High Elevation Forest Drainages
Pingjun Li and Thomas E. Martin
In Memoriam: Frederick Nathan Hamerstrom
John T. Emlen
Covers
Front Matter
The Auk
Back Matter
The Auk
Short Communications
Dipper Nestlings Fed by a Gray Wagtail
Sonja I. Yoerg and John O'Halloran
Mate Attraction by Autumnal Song in the Northern Mockingbird (mimus Polyglottos)
Cheryl A. Logan and Laura E. Hyatt
Measurement Error of External and Skeletal Variables in Birds and Its Effect on Principal Components
S. C. Lougheed, T. W. Arnold, and R. C. Bailey
Marine Protein Contributions to the Diet of Northern Saw-whet Owls on the Queen Charlotte Islands: a Stable-isotope Approach
Keith A. Hobson and Spencer G. Sealy
Commentaries
Confusions of Mass and Size
Theunis Piersma and Nick C. Davidson
On the Use of Tape Recorders in Avifaunal Surveys
Theodore A. Parker III