Black-headed Gull (2015-149)
Contributing photographers indicated by (ph.)
Corroborating observers and additional sources:
Thomas A. Benson (ph.)
Jon L. Dunn
Jim Gain (ph.)
Caroline Lambert (ph.)
Curtis A. Marantz (ph.)
Mark J. Rauzon (ph.)
John C. Sterling (ph.)
Scott B. Terrill (ph.)