Contents
Speciation in Sapsuckers (sphyrapicus): Ii Sympatry, Hybridization, and Mate Preference in S Ruber Daggetti and S Nuchalis
Ned K. Johnson and Carla Bowman Johnson
Philopatry, Site Tenacity, and Mate Fidelity in the Semipalmated Sandpiper
Cheri L. Gratto, R. I. G. Morrison, and Fred Cooke
Notes and News
The Auk
The Regulation of Egg Temperatures and Attentiveness Patterns in the Dusky Flycatcher (empidonax Oberholseri)
Martin L. Morton and Maria E. Pereyra
Some Effects of Wing Tags on Breeding Ring-billed Gulls
Linda K. Southern and William E. Southern
Nutrient Content of Eggs and the Energetics of Clutch Formation in the Boat-tailed Grackle
G. Thomas Bancroft
Clutch Size, Timing of Laying, and Reproductive Success in a Colony of Great Blue Herons and Great Egrets
Helen M. Pratt and David W. Winkler
A Search for Stability Gradients in North American Breeding Bird Communities
Barry R. Noon, Deanna K. Dawson, and John P. Kelly
A Phenetic Analysis of the Redpolls Carduelis Flammea Flammea and C Hornemanni Exilipes
Declan M. Troy
Hummingbird Flight Speeds
Frank B. Gill
An Analysis of Plumage and Morphological Characters of the Two Color Forms of the Western Grebe (aechmophorus)
Robert W. Storer and Gary L. Nuechterlein
Seasonal Changes in the Habitat Distribution of Transient Insectivorous Birds in Southeastern Arizona: Competition Mediated?
Richard L. Hutto
100 Years Ago in the Auk
The Auk
Nutrient Reserves and the Energetics of Reproduction in American Coots
Ray T. Alisauskas and C. Davison Ankney
Dialects in a Call Associated with Pair Interactions in the Black-capped Chickadee
Millicent S. Ficken, Robert W. Ficken, and Karen M. Apel
Rainfall and Winter Sparrow Densities: a View from the Northern Great Basin
William F. Laurance and Eric Yensen
In Memoriam: Charles Henry Blake
Oliver L. Austin Jr.
In Memoriam: Emerson a Stoner
L. Richard Mewaldt
In Memoriam: Constantine Walter Benson, Obe
G. Stuart Keith
Brewster and Coues Awards
The Auk
Covers
Front Matter
The Auk
Back Matter
The Auk
Short Communications
Autumnal Bird Migration Over the Windward Caribbean Islands
Timothy C. Williams
Investigator Perturbation and Reproduction of the Cliff Swallow
Gary D. Hamilton and Robert F. Martin
Snail Kite Kleptoparasitism of Limpkins
Bruce W. Miller and Ronald L. Tilson
Basal Metabolic Rate in Tropical Seabirds
Ted N. Pettit, Hugh I. Ellis, and G. Causey Whittow
Winter Range Expansion of the Long-billed Curlew (numenius Americanus) to South America
Raymond Mcneile Ram
Survivorship in Hummingbirds: is Predation Important?
Richard S. Miller and C. L. Gass
Function of a Rail Mystery" Call"
Richard Zembal and Barbara W. Massey
Do Blue Grouse Form Leks?
Richard A. Lewis
Selective Alarm Calling by Downy Woodpeckers in Mixed-species Flocks
Kimberly Sullivan
Daily Energy Expenditure by Female Savannah Sparrows Feeding Nestlings
Joseph B. Williams and Kenneth A. Nagy
A Natural Occurrence of Foster Parenting by a Female Mountain Bluebird
David J. Hayes, Robert R. Felton, and Robert R. Cohen
Food Habits of Long-eared Owls (asio Otus) at a Communal Roost Site during the Nesting Season
T. H. Craig, E. H. Craig, and Leon R. Powers
Visual Angle and Formation Flight in Canada Geese (branta Canadensis)
Frank H. Heppner, Jeffrey L. Convissar, Dennis E. Moonan Jr., and John G. Anderson
Differential Contribution of the Sexes to Prefledged Young in Red-throated Loons
T. E. Reimchen and Sheila Douglas
Do Female Red-winged Blackbirds Limit Harem Size? I a Removal Experiment
T. Andrew Hurly and Raleigh J. Robertson
Commentary
Did Tree Swallows Cross a Polygyny Threshold?
Robert Simmons