North America’s smallest rattlesnake
September 1, 2009 23 Comments
Despite tramping through the brush with great frequency during most of my life, I haven’t really seen that many noteworthy reptiles. I don’t know whether its because I’ve failed to actually encounter them or whether my singleminded obsession with insects above all other things natural has instead prevented me from seeing what was right in front of me. Regardless of the reason, all that has seemed to change during the past two seasons (strangely coincident with my decision to start carrying a camera), and I now seem to be enjoying a bit of a reptile bonanza. Last summer I featured a super-aggressive prairie rattlesnake from a trip to the Black Hills of South Dakota and an uncooperative dusty hognosed snake from Missouri’s critically imperiled sand prairies (both first-time sightings for me). The reptilian treats continued this year – I saw my first juvenile Osage copperhead in May to go along with the several adults that I’ve encountered, and shortly afterwards during a June trip to northwestern Oklahoma I was treated to a gorgeous male eastern collard lizard, two Texas horned lizards, and a much more cooperative western hognosed snake (the last two being first-time sightings for me). There was another herp that I saw during that Oklahoma trip, but I did not feature it here because I had stupidly declined to strap the camera bag to my back during a quick look at a roadside habitat. That sighting was another first-timer for me – a western pygmy rattlesnake (Sistrurus miliaris streckeri). I’m no herp expert, so wasn’t sure what it was at the time, but I later learned that its small size and distinctive markings were quite diagnostic.
Amazingly, I encountered this same species again just a few weeks later during a visit to the White River Hills of extreme southwestern Missouri. It was during the second of two trips to the region to search for the stunningly beautiful bumelia longhorned beetle, Plinthocoelium suaveolens plicatum (family Cerambycidae), and the weather during that day – continuous drizzle and low, threatening clouds – had not been at all conducive for finding such a sun loving beetle. After searching an area where I knew the beetles occurred, without success, daughter Madison and I resigned that the drizzle was here to stay and decided to pass the rest of the day with some hiking at one of Missouri’s most spectacularly wild and beautiful places, Hercules Glades Wilderness. A splendid mix of post oak savannahs and limestone glades intersperses through the oak/hickory forests in these rugged hills, creating some of Missouri’s most scenic vistas. Near the end of the hike at the edge of one of these glades on the high point of Coy Bald, I saw this little individual coiled up underneath an eastern red-cedar (Juniperus virginiana) tree. Unlike the terrifyingly aggressive prairie rattlesnakes I encountered in South Dakota last fall, this snake seem to be relying upon its cryptic coloration to avoid detection, rattling only after I had approached quite closely… or maybe it was only then I could actually hear the rattle, which was barely audible and sounded much like the buzz of a small katydid.
Pygmy rattlesnakes are the smallest rattlesnakes in North America, growing to around 15-25 inches long – this individual looked to be about 18-20 inches in length. They are one of only two U.S. species in the primitive rattlesnake genus Sistrurus - the other being the larger wet prairie inhabiting massasauga (S. catenatus). All other rattlesnakes (28 species, 13 in the U.S.) belong to the genus Crotalus (Smith et al. 2001). Western pygmy rattlesnakes are not really a western U.S. species, but rather the westernmost subspecies of this southeastern U.S. species (with subspecies miliarius and streckeri occupying the northeastern and southeastern portions, respectively, of its range). In Missouri, it is not nearly as common as the timber rattlesnake (Crotalus horridus), occurring only in the extreme southern Ozarks along the border with Arkansas and up into the St. Francois Mountains of the eastern Ozarks (Johnson 1997). Although no known human deaths have ever been caused by this species, known locally as the “ground rattler,” it is nevertheless poisonous and worthy of respect. I must admit to having been lulled a little bit by its calmness – much like the juvenile copperhead I photographed in May – and found myself tempted to approach ever closer for photographs. The photograph below represents the closest that I was able to get before it began “striking” at me – whether these were bluff strikes intended to frighten or actual attempts to bite I do not know. Suffice it to say that I “got the message” and ended my attempts to get even closer. Daughter Madison watched in nervous amazement as all this was going on, and afterwards I tried to impress upon her young, virgin mind what a rare and wonderful experience we’d just had. Perhaps I succeeded, as this was the first story she told to her head-shaking mother upon our return home the following evening!
Photo details: Canon 100mm macro lens on Canon EOS 50D, ISO 100, 1/250 sec, f/9-10, MT-24EX flash 1/2 power through diffuser caps.
Johnson, T. R. 1997. The Amphibians and Reptiles of Missouri. Missouri Department of Conservation, Jefferson City, 368 pp.
Smith, H. M., E. D. Brodie, D. M. Dennis and S. Barlowe. 2001. Reptiles of North America: A Guide to Field Identification. Golden Field Guide from St. Martin’s Press, New York, 240 pp.
Copyright © Ted C. MacRae 2009