Witmer Stone (September 22, 1866 – May 24, 1939) was an American ornithologist, botanist, and mammalogist, and was considered one of the last of the “great naturalists.” Stone is remembered principally as an ornithologist. He was president of the American Ornithologists’ Union (AOU) 1920–23, and was editor of the AOU's periodical The Auk 1912–1936. He spearheaded the production of the 4th edition of the AOU checklist, published in 1931. He worked for over 50 years in the Ornithology Department at the Academy of Natural Sciences of Philadelphia, eventually serving as Director of the institution. Stone was one of the founding members of the Delaware Valley Ornithological Club (DVOC) in 1890 and was actively involved in the organization for the remainder of his life. Stone was one of only two scientists (Joseph Grinnell was the other) to serve as president of both the AOU and the American Society of Mammalogists, and he co-authored two popular books about mammals. His outstanding botanical contribution was The Plants of Southern New Jersey, published in 1911. Stone spent many summers at Cape May, New Jersey, summering there annually starting in 1916. He is best remembered for his two-volume classic Bird Studies at Old Cape May, which was published by the DVOC in 1937, two years before his death.