eWestern BirdsThe Quarterly Journal of Western Field Ornithologists
Vol. 33, No. 4
Western Field Ornithologists
Noteworthy Waterbird Records in the Delta of the Río Colorado, Mexico
Eric Mellink, José Alfredo Castillo, and Aimeé De La Cerda
ABSTRACT: Surveys of the Río Colorado delta in summer 2002 revealedabandonment of one large heronry but the existence of another large and severalsmall, inconspicous heronries previously nonexistent or undetected. Most notableamong these mixed-species colonies were two nests of the Tricolored Heron and twofledglings of the Reddish Egret, representing considerable northward extensions ofthese species' breeding ranges.