(help)CS1 maint: uses authors parameter (link) Podiceps auritus in the Flickr: Field Guide Birds of the World Podiceps auritus on Avibase BTO BirdFacts
Archived 2016-03-04 at the Wayback Machine Podiceps nigricollis in the Flickr: Field Guide Birds of the World Podiceps nigricollis on Avibase BTO BirdFacts
videos, photos, and sounds at the Internet Bird Collection Crex crex in the Flickr: Field Guide Birds of the World Feathers of Corn crake (Crex crex) Archived
Brown Pelican photo gallery at VIREO (Drexel University) Field Guide Page on Flickr Interactive range map of Pelecanus occidentalis at IUCN Red List maps