Contents
Behavior of the Grey-capped Social Weaver (pseudonigrita Arnaudi) in Kenya
Nicholas E. Collias and Elsie C. Collias
Rainfall on the Gal
Peter R. Grant and Peter T. Boag
Acquisition of Plumage Polymorphism in White-throated Sparrows
Carter T. Atkinson and C. John Ralph
Notes and News
The Auk
Range Expansion and Diurnal Changes in Dispersion of the Brown-headed Cowbird in the Sierra Nevada
Stephen I. Rothstein, Jared Verner, and Ernest Stevens
The Breeding Biology of the Fork-tailed Storm-petrel (oceanodroma Furcata)
P. Dee Boersma, Nathaniel T. Wheelwright, Mary K. Nerini, and Eugenia Stevens Wheelwright
Brown-headed Cowbird (molothrus Ater) Mortality in an Urban Winter Roost
D. M. Johnson, G. L. Stewart, M. Corley, R. Ghrist, J. Hagner, A. Ketterer, B. Mcdonnell, W. Newsom, E. Owen, and P. Samuels
Water Dependence of Birds in a Temperate Oak Woodland
Pamela L. Williams and Walter D. Koenig
Guilds and Community Organization: Analysis of an Oak Woodland Avifauna in Sonora, Mexico
Peter B. Landres and James A. Macmahon
Seventeen Bird Species New to Peru from the Pampas De Heath
Gary L. Graham, Gary R. Graves, Thomas S. Schulenberg, and John P. O'Neill
Little Blue Heron Breeding Behavior
James A. Rodgers Jr.
Ornithologists as Unconscious Theorists
John R. Krebs
Welcome Mathematicians
John T. Emlen
When I Grow Up ""
Martin Cody
Ornithological Theory: Whence and Whither?
James R. King
On Digesting a Theory
H. Ronald Pulliam
On the Philosophical Basis of Ornithology
Stephen D. Fretwell
Mathematics, Ecology, and Ornithology
Simon A. Levin
Covers
Front Matter
The Auk
Back Matter
The Auk
Short Communications
Nest Grouping and Productivity in the House Sparrow
W. Bruce Mcgillivray
Louisiana Herons Gleaning Dragonflies
E. Scott Clark
Aspects of the Annual Cycle in Highland Populations of the Rufous-collared Sparrow, Zonotrichia Capensis
Paul Handford
First Records of the Spotted Rail (pardirallus Maculatus) on the Island of Hispaniola
Annabelle Stockton Dod