John Cassin, 1813-1869. Photo via Wikimedia Commons.

Birds: Cassin’s Birds

There are a ton of birds in the world, right? Well, not so any more. We are losing millions of birds each year to global warming, pollution and reduction of habitat that can sustain birds. More and more species are on the brink of collapse. With the dwindling nature of the bird world, here are some thoughts on one of the most thoughtful ornithologists and naturalists getting the language and identification ready for the rest of us to rush in with our binoculars and bird life-lists to check them off on the way to the next pond.

Cassin’s Kingbird from Report on the U.S. and Mexican Boundary Survey, edited by Spencer Fullerton Baird (artist unknown). Image via Wikimedia Commons.

After spending many summers with the Prairie Trek Expeditions in New Mexico, I have gained an appreciation for the desert. It is not the dry, open country, desolation that attracts me, but the life. Take birds for example. In many states of the Southwest lives a lemon-yellow, storm-cloud gray flycatcher known as Cassin’s Kingbird. This kingbird is a prolific songster, which makes it fun to watch as it balances on a perch and flies back and forth catching insects and singing. This and many other birds were named by John Cassin, who was a major figure of nineteenth-century ornithology. He has nine birds named after him worldwide, and five from North America. Only Alexander Wilson (featured in this Birds Post) is as prolific as Cassin in the namesake category. Perhaps it is worthwhile to explore the man, before exploring his named fliers. [1]

The Prodigy Naturalist

Born in Delaware County, Pennsylvania, in 1813, John Cassin was a prodigy with plant and flower identification. By the age of 17 he was drawing those flowers in remarkable detail, and even identifying plant species that were missing from his botany textbook. Eventually, he combined his naturalist’s eye with the meticulous attention of a scientist, bringing a new level of rigor and scientific method to American ornithology. [2]

At the age of 20, Cassin co-created the Delaware County Institute of Science in Media, PA. Cassin moved to Philadelphia in 1834, where he joined the Academy of Natural Sciences. He was appointed as an honorary curator at the Academy. As an American naturalist with a budding interest in taxonomy, there were few better places to start your studies in the States than Philadelphia. Today known as the Academy of Natural Sciences of Drexel University, it is the oldest natural history museum in the U.S. At the time, the Academy hosted the largest collection of bird skins in existence—some 25,000—including specimens from Australia, India and Africa.

Black-headed Bee-eater and Blue-headed Bee-eater by Otto Koehler, from an 1860 article by John Cassin in the Journal of the Natural Academy of Sciences of Philadelphia.

Over his career, Cassin described 193 new bird species. African birds were a particular fascination for Cassin, and today four African species, including a honeyguide and a hawk-eagle, are named for him. Eventually Cassin was appointed both vice president and corresponding secretary during his 26 years at the Academy.

Ornithology was not yet a full-time paying job in the 1830’s. To support his wife and two children Cassin managed a lithograph company where many of his works were printed. “It is hard work, this studying foreign birds,” he wrote. “It would do very well were there no arrangement to be made for ensuring the supply of bread and butter.” Nonetheless he was prolific: his output included 3 books, some 15 articles, and reports of U.S. government expeditions abroad, some of which he accompanied.

Even while running his lithography business, Cassin become the most knowledgeable ornithologist of the mid-nineteenth century, including Alexander Wilson and John J. Audubon. Many of the specimens Cassin worked with were originally collected by Wilson on his western expeditions. Whereas his predecessors sought to describe and illustrate North America’s birds one species at a time, Cassin took a more systematic view. Aided by his encyclopedic knowledge of the Academy’s holdings, Cassin examined the ways in which birds are related to each other.

Black-capped Chickadee from Illustrations of the birds of California, Texas, Oregon, British and Russian America (1862). Illustration by John Cassin, image courtesy of Wikimedia Commons.
Black-capped Chickadee by George G. White, from Cassin’s 1862 book Illustrations of the Birds of California, Texas, Oregon, British and Russian AmericaImage via Wikimedia Commons.

Cassin believed a scientist needed to go beyond just field observation and apply scientific rigor to their work. “It is by no means desirable to be exclusively a naturalist of the woods,” Cassin wrote. “There must be a combination of theoretical and practical acquirements.”

Range of the Cassin’s Kingbird, National Audubon Society Map

Cassin joined the Union Army during the Civil War, and served time as a prisoner of the Confederates.

Shortly after his time in prison, Cassin’s health started to fail. It seems likely that his work with bird carcass preserved with arsenic became a major contributor to his poor health. Cassin himself noted the toll that the toxin took on him, writing that his work meant “mortgaging myself by perpetual lease to arsenic and liver complaint.” He died in January 1869, at the age of 56. His death record lists “remittent fever” as the cause. Remittent fevers exhibit a pattern of temperature spikes which do not touch the baseline and remain 1°-2°C above normal in 24 hours. Fevers due to most infectious diseases are remittent and can prove deadly. [3]

Cassin’s determination and insight inspired the ornithologists who followed him. George Lawrence, who had conducted surveys in the Pacific for Cassin, named a kingbird for him. William Gambel named a sooty, tennis-ball-sized auk Cassin’s Auklet. A red finch of the western mountains was named Cassin’s Finch by Spencer Fullerton Baird, the first curator of the Smithsonian Institution. Samuel Washington Woodhouse described the Cassin’s Sparrow, and Hungarian-born explorer John Xantus collected the first Cassin’s Vireo. [4]

A century and a half after his death, birds as different as seabirds and sparrows still bear Cassin’s name, as a reminder of his critical role in shaping American ornithology. Elliot Coues [5] paid tribute to Cassin’s legacy on hearing of his passing, writing to a colleague, “…many as are our American ornithologists—high as some stand in American ornithology—there is none left in all our land who can lift up the mantle that has fallen from Cassin’s shoulders.”



[1] Five birds from North America are named in his honor: the Cassin’s aukletCassin’s kingbirdCassin’s vireoCassin’s sparrow, and Cassin’s finch. The periodic cicada Magicicada cassini and the mineral Orthoclase Variety Cassinite are also named for him.

In 1901, the journal of the Delaware Valley Ornithological Club was renamed Cassinia in his honor.

[2] A marvelous article was written by Elizabeth Serrano entitled “The People Behind The Birds Named For People: John Cassin,” published August 28, 2019. It is heavily referenced here, as it is a fine work. Serrano does a great job of introducing the birdwatching public to early American ornithologists and naturalists like Alexander Wilson or John J. Audubon. John Cassin is the sort of character that most naturalists would miss without the resonance of the worldwide web. Elizabeth Serrano ’20 is an Animal Science major at Cornell University. Her work on this story was made possible by the Cornell Lab of Ornithology Science Communication Fund, with support from Jay Branegan (Cornell ’72) and Stefania Pittalue.

[3] Remittent Fever

[4] If these ornithologists’ names Gambel, Lawrence, Baird, Woodhouse and Xantus sound familiar, it’s because of birds like Gambel’s Quail, Lawrence’s Goldfinch, Baird’s Sandpiper, Woodhouse’s Scrub-Jay, and Xantus’s Hummingbird. Gambel and Woodhouse are also noted as naturalists with trees and toads sharing his last name.

[5] Elliott Ladd Coues was an American army surgeon, historian, ornithologist, and author. He led surveys of the Arizona Territory, and later as secretary of the United States Geological and Geographical Survey of the Territories.