The collection consists of 50 original illustrations created by Edward Lear (1812-1888) executed primarily in watercolour and pencil. These works are part of Lear's Fifty Original Drawings of Birds and a Few Indistinct Pencil Sketches, published between 1835 and 1836. The illustrations and sketches feature depictions of a variety of bird species, including raptors, parrots, cranes, and waterfowl.

Among the species illustrated are the White-tailed Eagle, Grey Parrot, Whooper Swan, Andean Condor, Peregrine Falcon, and King Vulture. The illustrations are often annotated with descriptive details about the colours and features of the birds. Some also include pencil sketches and test patches of color.

Some of the illustrations include unidentified species, including a raptor with prey, an owl, and various parrots. Several of the illustrations are signed and dated by the artist, with the majority titled in pencil at the bottom of each sheet.