early american natural history

realms of fin and

feet and wing



"So talk'd the spirited sly Snake" : The Rattlesnake a Hypnotist


For most American students, at some point in science class, one film or another will feature a rattlesnake dramatically striking at the lens, in a way that, depending on the student, is either frightening, indescribably cool, or both.


Long before we could watch rattlesnakes strike from the comfort of our computer or television (or perhaps if you are old enough to remember, projector screens), rattlesnakes were a highly symbolic image for Americans.  Rattlesnakes were a New World phenomenon, one that Americans feared but also embraced as a symbol of power.


Most Americans are familiar with the “Don’t Tread on Me” emblem used on the Gadsden flag used in support of the separating colonies in the Revolutionary War.  In addition many people may remember  the “Join or Die” cartoon created by Benjamin Franklin in 1759 to encourage unity with Britain during the French and Indian War and then later revived and used by the colonists seeking independence during the Revolutionary War. 1




In some instances, the British also identified rebelling American forces with the rattlesnake.  A British cartoon engraved by James Gillray from 1782 reveals an oversized American rattlesnake surrounding British forces at Saratoga and Yorktown.  The loop of the tail on the left side reveals a sign reading “Apartment for Rent” hanging from its rattle.  The snake states “The British Armies I have thus Burgoyn’d. And room for more I’ve got behind” Burgoyn'd is a play on one of the surrendering generals' names (Burgoyne at Saratoga and Cornwallis at Yorktown).  2   The verses underneath the cartoon read: "Britons within the Yankee Plains/ Mind how ye March and Trench/ The Serpent in the Congress Reigns/ As well as in the French."


Long before the American Revolution, Captain James Smith in 1630 mentions fear of the “rattell Snake” as a reason colonists wished to return to England.  It appears in his Advertisements for the Unexperienced Planters of New England, assuredly as a warning to potential new colonists.  The rattlesnake was, unfortunately, the evil snake in the new Eden of America. 3

Of particular interest from a natural historical point of view is the controversy over whether or not rattlesnakes could “fascinate” their prey.  The term fascinate in this sense means to mesmerize, or hypnotize prey to prevent their escape.  It’s difficult to resist visions of the Disney version of the Jungle Book, where Kaa’s snake eyes radiate alternating colors as he sings in a low voice, “Trust in me, just in me.”


Animations aside, this power of fascination was a central debate among natural historians.  The predilection among American natural historians for observation from the field over theory or experiment encouraged a wide range of reports of rattlesnakes fascinating their victims.  (For further discussion of observation over theory see Jefferson and the Mastodon and Swallow Submersion).


Cotton Mather, more famous for his role in the Salem Witch Trials than his early scientific endeavors, contributed accounts of the power of the rattlesnake to ‘fascinate’ its prey.   In his Curiousa Americana sent to the Royal Society’s Philosophical Transactions of 1714, he wrote “These Snakes frequently lie coiled at the Bottom of a great Tree, with their Eyes fixed on some Squirril above in the Tree; which tho’ seeming by his cries and leaping about, to be in a Fright, yet at last runs down the Tree, into the Jaws of the Devourer.” 4


The Puritan Jonathan Edwards gathered observations on the flora and fauna of America in parts of his Images or Shadows of Divine Things (ca. 1727) in which he describes the following:


The animal that is charmed by the serpent seems to be in great exercise and fear, screams and makes ado, but yet don’t flee away.  It comes nearer to the repent, and then seems to have its distress increased, and goes back again, but then comes still nearer than ever . . . . until at length they come so [near] that the serpent can lay hold of them.


He compares the helplessly mesmerized prey to those “sinners under the Gospel [who] are bewitched by their lusts . . . . [and who] return to it again and again . . . until Satan remedilessly makes prey of them." 5


William Byrd (1674–1744) also offered an account of the power of the rattlesnake, stating that it would stare at the prey until “by force of the Charm he falls down Stupify’d and Senseless.”


Mather, Edwards, and Byrd all explained in their accounts that these events, if not witnessed by themselves, were witnessed by people of repute, or in Mather’s case, were common knowledge to the Native Americans.  Reports of rattlesnake fascination, mostly of animals but occasionally of people, circulated throughout colonial America and were reprinted in British periodicals through the eighteenth century.


Mark Catesby (1683- 1749), traveling in the souther parts of the American colonies, included several illustration and descriptions of snakes in his publication.  Catesby’s main project was to represent the natural world of the American colonies as a survey of their possible continued colonization.  He was interested in the plants of a region and often depicted animals with plants they fed upon or were found near (a version of proto-ecology).  In depicting his “Green Snake” he reports that the snakes are harmless and that some colonist “carry them in their Bosoms.”  The plant with the snake is the Cassena vera which Catesby reports the Native Americans used to make a tonic. 6


The playful image of this plant and snake, both harmless and beneficial, resembles many of Catesby’s snakes.  Except for one: the rattlesnake.  7  In his depiction of the rattlesnake, Catesby departs from his image of harmony between animal and plant kingdom, removing all background from the snake.  The resulting image is more in keeping with natural history illustration conventions.  These conventions emphasize identification, and perhaps identifying the deadly snake was uppermost in Catesby’s vision for the illustration— being able to identify the rattler is one step towards avoiding its poison.  However, much of Catesby’s intended audience lived in England or Contiential Europe, where there was little danger of encountering a rattlesnake.  It is possible that the rattlesnake did not fit into Catesby’s desire through his illustrations and his books to bring the wild natural world of America into a more settled European order and harmony. 8



William Bartram (1739- 1823) also chose to discuss the rattlesnake as part of his more Romantic descriptions of the American wilderness in Travels (1791)


He writes of the rattlesnake with awe as  “a wonderful creature, when we consider his form, nature and disposition, it is certain that he is capable by a puncture or scratch of one of his fangs, not only to kill the largest animal in America, and that in a few minutes time, but to turn the whole body into corruption.”  Clearly, Bartram admires the power of the rattlesnakes bite, but softens this with the observation that “ he is never known to strike until he is first assaulted or fears himself in danger, and even then always gives the earliest warning by the rattles at the extremity of his tail.”   This fits well with Bartam’s view of the natural world being primarily one of harmony with mankind.  Bartram, too, seems to espouse the fascination theory, writing:


They are supposed to have the power of fascination in an eminent degree, so as to inthral their prey. It is generally believed that they charm birds, rabbits, squirrels and other animals, and by stedfastly looking at them possess them with infatuation; be the cause what it may, the miserable creatures undoubtedly strive by every possible means to escape, but alas! their endeavours are in vain, they at last loose the power of resistance, and flutter or move slowly, but reluctantly towards the yawning jaws of their devourers, and creep into their mouths or lay down and suffer themselves to be taken and swallowed. 9


Bartram does not claim in his writings to have witnessed this power himself.


The artist and museum collector Charles Willson Peale (1741-1827) kept live rattlesnakes in cages in his museum of natural history, a collection of specimens, portraits, and books on American natural history.  It was after observing Peale’s experiments with snakes in his museum that Benjamin Smith Barton wrote “Memoir Concerning the Facinating Faculty Which Has Been Ascribed to the Rattle-Snake, and Other American Serpents” wherein he argued strongly against the idea that snakes could hypnotize their prey.  He lamented that the “belief in the fascinating faculty of services has spread through almost all the civilized parts of North-America . . . . It has made its way into Europe.” Barton conjectured that the behavior of bird and other animals which were observed running or flying at snakes was most likely that of females protecting their young. 10


The debate continued well into the 19th century.  In 1822, a Mr. Neal exhibited two rattlesnakes in Virginia, assuring his audience that he had witnessed the snakes’ mesmerizing power: “As soon as the eyes meet, he says the process of charming commences” and the intended prey will approach the rattlesnake “overcome with apprehension, until approaching each other, the snake seizes him.” 11  The persistence can be attributed to a preference in America for accounts that were “from the field,” even if this field were a house or yard, over knowledge gained from experimentation or theorizing.  And to a continued belief in the observing powers of the amateur as equal to that of the expert.


In 1843, John Edwards Holbrook asserted in his North American Herpetology that the power of fascination lay only in the fear rattlesnakes evoked in the humans observing them.  Holbrook was one of many naturalists who criticized Audubon’s rendering of a mocking bird nest attacked by a rattlesnake, not on the grounds of fascination so much as that of accurately recording rattlesnake behavior.  Charles Waterton, a noteworthy English naturalist, criticized Audubon’s representation for similar reasons to Holbrook: that rattlesnakes did not climb trees.  In addition, Waterton asserted that the snakes did not bare their fangs in the manner shown by Audubon. 12  For Audubon, his observations in the wild attested to the behavior of rattlesnakes, and as an American naturalist, he did not see a need for replication of this in a controlled, experimental environment.  The European naturalists, along with a few Americans, doubted any observation that could not be replicated.



While the case of the fascinating power of rattlesnakes, and other snakes, did indeed turn out to be a myth, although a powerful one, Audubon’s observations about rattlesnakes raiding bird nests and their ability to bare their fangs turned out to be accurate, and was corroborated by other observers of rattlesnake behavior in America, much in the same way that the myth of the rattlesnake’s ability to fascinate its prey was supported by observation from the field.


Facts are strange.


Today, it seems the prey are the ones doing the mesmerizing— of the snakes.  Recent studies have shown  that rattlesnakes use infrared sensors to hone in on their prey.  One type of prey has developed a protein that counteracts the rattlesnake venom: the California ground squirrel.  These squirrels are apparently vigorous defenders of their young (who have yet to develop the venom protections), often biting and attacking snake’s tails. 13


Researchers at the University of California at Davis have concluded that the adult California ground squirrels have further adapted by heating up their tails during tail flagging— swiftly wagging their tails from side to side.  During the flagging, the heat in the  tail creates an infrared distraction for snakes pursuing squirrel young.


The researchers, however, verified their findings in laboratory experiments where they “exposed California ground squirrels to rattlesnakes in the lab. When they viewed the interaction through an infrared video camera, they saw that the squirrels' tails heated up. But if a gopher snake, which cannot sense infrared radiation, was put in with the squirrels, the squirrels' tails remained dark and cold while they waved them.” 14  Peale and Barton would have been proud: knowledge of the natural gained from repeatable experimentation in the lab.


To further test the ground squirrel theory, UC Davis researchers returned to the field.  But with a twist: they have developed what has been dubbed the "robosquirrel," a robot squirrel created from a taxidermy squired that can be sent out into the field to further test the relationship between tail flagging, heat, and rattlesnake response.  With live squirrels in the lab, researchers could not determine whether the rattlesnake was responding to the tail motion or the heat, but using the robosquirrel, they were able to activate heat and tail flagging separately, thus confirming that the rattlesnake responds to the heat, or infrared signal. 15


A far cry from Audubon’s drawings or Bartram’s descriptions, robosquirrel is a new approach to verifying knowledge in the field.




1. David Wilson, “The Iconography of Mark Catesby,” South Carolina Historical Magazine.

2. Christoph Imrscher. The Poetics of Natural History, Chapter 4 : “The Power of Fascination.” 149-187. New Brunswick, NJ: Rutgers University Press, 1999.

3. Ibid.

4. Ibid.

5. Ibid.

6. David Wilson, “The Iconography of Mark Catesby,” South Carolina Historical Magazine. Quotation from description  of Green Snake in Vol ii pg 57

7. Ibid.

8. Chaplin, Joyce E. “Mark Catesby, a Skeptical Newtonian in America,” Empire’s Nature Mark Catesby’s New World Vision, edited by Amy R. W. Meyers and Margaret Beck Pritchard. Chapel Hill :  University of North Carolina Press, 1998.

9. Bartram, William. Travels. (1791. Documenting the American South, 2001), chap. 10, http://docsouth.unc.edu/nc/bartram/bartram.html

10. Christoph Imrscher  “The Power of Fascination” in The Poetics of Natural History. New Brunswick, NJ: Rutgers University Press, 1999.

11. Ann Shelby Blum,  Picturing Nature American Nineteenth Century Zoological Illustration, (Princeton, N.J. : Princeton University Press, 1993).

12. Ibid.

13. “Squirrel Has Hot Tail to Tell Snakes,” Scientific American, August 14, 2007.

14. “Squirrel Lightsaber,” Science Scope, October 1, 2007.

15.  “Robosquirrels Versus Rattlesnakes” UCDavis News and Information


Arkansas Frameworks:

• Biology: Ecology and Behavioral Relationships: 8. Students shall demonstrate an understanding of ecological and behavioral relationships among organisms.

• Nature of Science: 10. Students shall demonstrate an understanding that science is a way of knowing. & 14. Students shall describe the connections between pure and applied science.

• Environmental Science: Social Perspectives: SP.3.ES.6 Research how political systems influence

environmental decisions



Infrared images of California ground squirrels &  a robosquirrel from UC Davis

This site  was created through a fellowship from the William Reese Company

and completed through the  Crystal Bridges Museum of American Art Library