NPSpecies

An abundant winter resident along the Colorado River especially from Glen Canyon Dam to RM 11 but also downstream to the Little Colorado and on upper Lake Mead (Spence 2006). It is among the many species that have begun to winter on the river below Glen Canyon Dam since the publication of the last checklist. As with many other waterfowl, the timing of arrival for winter residents is not well documented in the region, but large numbers are typically present by November. Numbers along the river drop in April, with some birds present as late as 13 May. It is a rare spring and fall migrant and an irregular summer visitor at open water elsewhere throughout the region from April to September, with one record from 4 Nov. Data source: Gatlin, BP. 2011. Annotated Checklist of the Birds of the Grand Canyon Region. 3rd edition.

(Anas strepera) Gadwall is an abundant winter resident along the Colorado River especially from Glen Canyon Dam to RM 11 but also downstream to the Little Colorado and on upper Lake Mead (Spence 2006). It is among the many species that have begun to winter on the river below Glen Canyon Dam since the publication of the last checklist. As with many other waterfowl, the timing of arrival for winter residents is not well documented in the region, but large numbers are typically present by November. Numbers along the river drop in April, with some birds present as late as 13 May. It is a rare spring and fall migrant and an irregular summer visitor at open water elsewhere throughout the region from April to September, with one record from 4 Nov. Data source: Gatlin, BP. 2011. Annotated Checklist of the Birds of the Grand Canyon Region. 3rd edition.