The head and neck of these birds is bare of feathers.
Worthington Hooker, The Child's Book of Nature (New York:Harper & Brothers, Franklin Square, 1886) 128
TIFF (full resolution)
1386×1176, 1.6 MiB
Large GIF
1024×868, 252.6 KiB
Medium GIF
640×543, 113.4 KiB
Small GIF
320×271, 31.1 KiB