Who Is Cassin?

Cassin's Finch
The Cassin's finch is just one of many birds named for John Cassin. PEHart

Many familiar birds share the name Cassin, but why? John Cassin is the notable name behind these birds, and his love of birds and dedication to their study is well deserving of the honor of having so many species bear his name.

Name: John Cassin
Birth: September 6, 1813, Upper Providence Township, Pennsylvannia, United States
Death: January 10, 1869, Philadelphia, United States

About John Cassin

Raised as a Quaker and one of nine children, John Cassin developed an interest in the natural world during childhood, and interest that would figure prominently throughout his life. He was an excellent student, particularly of the sciences, and even as a teen was making notes and additions to his botany textbook. While birds were his passion, he also showed strong interest in insects and plants, and in 1833 he was one of five founders of the Delaware County Institute of Science, which includes exhibits on minerals and an extensive herbarium in addition to bird exhibits.

In 1837, Cassin married Hanna Wright, and they would eventually have two children, a daughter, Rachel, and a son, William Isaac.

During his adult life, Cassin worked in a variety of capacities, including merchant, artist, writer, botanist, publisher and ornithologist. His attention to detail, particularly for categorizing specimens, made him an authoritative expert on plants, insects and birds, and his advice was often sought. In 1842 he was selected as the honorary curator at the Philadelphia Academy of Natural Sciences, an unpaid position that he worked at diligently, cataloging and clarifying the institution's collection of more than 25,000 birds, at the time the largest such collection in the world.

Cassin wrote multiple government reports about birds from different exploratory expeditions, and sought to publish his own work, Illustrations of the Birds of California, Texas, Oregon, British and Russian America in 1856. The book was intended as a western extension of John James Audubon's Birds of North America, but because of increasing unrest and the breakout of the Civil War, only Cassin's first volume was published. Cassin himself served in the Union Army during the war, and spent time in a Confederate prison after being captured.

Cassin enjoyed being in the field to observe birds, particularly birding by ear, but he believed that true contributions to science were to be made through detailed study of skins and preserved specimens, carefully denoting the minute differences that separate species. He disapproved of the field-based observations of Audubon, though it is believed the two met only once in 1845. Instead, Cassin's focus was on the exact scientific nomenclature of birds and in comparing North American birds to ornithology across the world. This unique expertise made him the first true taxonomist in North America. He continued his research until his death in 1869, a death likely from extensive arsenic exposure from years of handling bird skins preserved with the toxin. He was aware of the toxic effects of arsenic at the time of his death, but chose to continue his work to the end, dedication well deserving of high honors among birders.

John Cassin is buried in Laurel Hill Cemetery, in Philadelphia, Pennsylvania.

Contributions to Birding

While he may not have been as active in the field as other famous birders, John Cassin's contributions are nonetheless impressive and have greatly influenced not only North American ornithology, but ornithology and birding around the world.

  • During his time as the curator of the Philadelphia Academy of Natural Sciences, Cassin named 198 birds not previously distinguished by either John James Audubon or Alexander Wilson. Among them were the white-headed woodpecker, Heerman's gull, acorn woodpecker, wrentit and black-throated sparrow.
  • Cassin wrote a wide variety of publications detailing regional avifauna and coordinating data from multiple sources into more extensive reports on birds. He worked to revise, update and correct many existing reports, including studies of birds in Africa, Canada, Mexico and South America.
  • In 1842 Cassin was the first to collect and catalogue a specimen of the Philadelphia vireo, which he named for the area where he collected the bird, but only later was it discovered that these birds are only passage migrants through Pennsylvania.
  • Cassin's Illustrations of the Birds of California, Texas, Oregon, British and Russian America was an extensive work that featured not only detailed illustrations of the birds, but also included ornithological data on the species and exacting detail about their characteristics.
  • The Delaware Valley Ornithological Club (founded 1890) named its journal – Cassinia – in honor of John Cassin.

Birds Named After John Cassin

While Alexander Wilson has the distinction of the most North American bird species named by others in his honor, John Cassin has many more species bearing his name from around the world. Many of the names are due to his detailed taxonomy work which led him to using his own name many times, particularly in scientific nomenclature, but the name is no less familiar to birders worldwide.

North American species named for Cassin include:

  • Cassin's Auklet (Ptychoramphus aleuticus)
  • Cassin's Finch (Carpodacus cassinii)
  • Cassin's Kingbird (Tyrannus vociferans)
  • Cassin's Sparrow (Peucaea cassinii)
  • Cassin's Vireo (Vireo cassinii)

Additional species named for John Cassin include:

  • Baudo Oropendola (Psarocolius cassini) – South America
  • Black-Throated Malimbe (Malimbus cassini) – Africa
  • Cassin's Grey Flycatcher (Muscicapa cassini) – Africa
  • Cassin's Hawk-Eagle (Aquila africana) – Africa
  • Cassin's Honeybird (Prodotiscus insignis) – Africa
  • Cassin's Spinetail (Neafrapus cassini) – Africa
  • Dusky-Faced Tanager (Mitrospingus cassinii) – Central and South America
  • Eastern Long-Tailed Hornbill (Horizocerus cassini) – Africa
  • Golden-Collared Woodpecker (Veniliornis cassini) – South America
  • Grey-Chested Dove (Leptotila cassinii) – Central America

Photo – Cassin's Finch © PEHart