Audubon developed his own methods for drawing birds. First, he killed them using fine shot. He then used wires to prop them into a natural position, unlike the common method of many ornithologists, who prepared and stuffed the specimens into a rigid pose. When working on a major specimen like an eagle, he would spend up to four 15-hour days, preparing, studying, and drawing it.[78] His paintings of birds are set true-to-life in their natural habitat. He often portrayed them as if caught in motion, especially feeding or hunting. This was in stark contrast to the stiff representations of birds by his contemporaries, such as Alexander Wilson. Audubon based his paintings on his extensive field observations.

He worked primarily with watercolor early on. He added colored chalk or pastel to add softness to feathers, especially those of owls and herons.[79] He employed multiple layers of watercoloring, and sometimes used gouache. All species were drawn life size which accounts for the contorted poses of the larger birds as Audubon strove to fit them within the page size. Smaller species were usually placed on branches with berries, fruit, and flowers. He used several birds in a drawing to present all views of anatomy and wings. Larger birds were often placed in their ground habitat or perching on stumps. At times, as with woodpeckers, he combined several species on one page to offer contrasting features. He frequently depicted the birds’ nests and eggs, and occasionally natural predators, such as snakes. He usually illustrated male and female variations, and sometimes juveniles. In later drawings, Audubon used assistants to render the habitat for him. In addition to faithful renderings of anatomy, Audubon also employed carefully constructed composition, drama, and slightly exaggerated poses to achieve artistic as well as scientific effects.

Audubon’s influence on ornithology and natural history was far reaching. Nearly all later ornithological works were inspired by his artistry and high standards. Charles Darwin quoted Audubon three times in On the Origin of Species and also in later works. Despite some errors in field observations, he made a significant contribution to the understanding of bird anatomy and behavior through his field notes. Birds of America is still considered one of the greatest examples of book art. Audubon discovered 25 new species and 12 new subspecies.

– He was elected to the Royal Society of Edinburgh, the Linnaean Society, and the Royal Society in recognition of his contributions.
– The homestead Mill Grove in Audubon, Pennsylvania, is open to the public and contains a museum presenting all his major works, including Birds of America.
– The Audubon Museum at John James Audubon State Park in Henderson, Kentucky, houses many of Audubon’s original watercolors, oils, engravings and personal memorabilia.
– In 1905, the National Audubon Society was incorporated and named in his honor. Its mission “is to conserve and restore natural ecosystems, focusing on birds…”
– He was honored by the United States Postal Service with a 22¢ Great Americans series postage stamp.
– On December 6, 2010, a copy of Birds of America was sold at a Sotheby’s auction for $11.5 million, the second highest price for a single printed book.
– Audubon is the subject of the 1969 book-length poem, “Audubon: A Vision” by Robert Penn Warren.
– On 26 April 2011, Google celebrated his 226th birthday by displaying a special Google Doodle on its global homepage.