eWestern Birds

Contents

MAIN ARTICLES

Fifth Report of the Alaska Checklist Committee, 2018–2022
Daniel D. Gibson, Steven C. Heinl, Theodore G. Tobish Jr., Aaron J. Lang, Jack J. Withrow, Lucas H. DeCicco, Nicholas R. Hajdukovich, and Robert L. Scher

Vocalizations and Bill Measurements May Resolve Some Questions about Taxonomic Relationships within the Fox Sparrow Complex
Edward R. Pandolfino, Lily A. Douglas, and Peter Pyle

The Potential Identification and Distribution of Ainley’s Storm-Petrel at Sea by Timing of Molt
Desmond E. Sieburth, Ryan Terrill, and Peter Pyle

NOTES

First Record of the Brown-headed Cowbird Parasitizing the Mangrove Warbler in Baja California Sur
Gerardo Marrón, Roberto Carmona, Jorge Cristerna, and Sergio Águila

Nest-Box Use and Apparent Double Brooding by Red-breasted Nuthatches in California
Phillip J. Capitolo and Barbara Doe

Apparent Object Play in the Northern Harrier
Jeffery T. Wilcox, Luc Myers, Ian Jackson, and Jeff A. Alvarez

Course Review: Great Courses’ National Geographic Guide to Birding in North America
Ned Bohman

Front cover photo by © Rodney Ungwiluk Jr. of Gambell, Alaska: Icterine Warbler (Hippolais icterina), Gambell, St. Lawrence Island, Alaska, 22 September 2022. Of the many astonishing birds new to Alaska that the Alaska Checklist Committee reports in this issue of Western Birds, among the most remarkable is the Icterine Warbler, a species of western Eurasia known to nest east only as far as Nazorovo, Krasnoyarsk Krai, Russia (56° 02΄ N, 90° 23΄ E)—5000 km from Gambell.

Back cover photo by © Gerardo Marrón of La Paz, Baja California Sur, Mexico: Mangrove Warbler (Setophaga petechia castaneiceps), El Conchalito, Ensenada de La Paz, Baja California Sur, 1 July 2014. The expansion of the breeding range of the Brown-headed Cowbird has now reached the tip of the Baja California Peninsula, where that brood parasite has been well established for only about 20 years. Thus the birds endemic to Baja California Sur, such as this subspecies of the Yellow Warbler, represent a new generation of naïve hosts confronting cowbird parasitism for the first time.