An especially beautiful Central American Eyelash Viper that I found in Costa Rica last year on a family vacation.

An especially beautiful Central American Eyelash Viper that I found in Costa Rica last year on a family vacation.

Close up with a Black Headed Calico Snake, a harmless mimic of the Hemphrich’s Coralsnake which also lives in the area. Found a couple of years ago in Peru.

An orange Southwestern Speckled Rattlesnake making good on its name. While its bands are still visible, the chaotic distribution of colors can make this animal very difficult to see in context. This one lives near quite a few people with hundreds hiking right past it every weekend, but bites nobody.

Southwestern Speckled Rattlesnake
(Crotalus pyrrhus)https://rattlesnakesolutions.com/SpeckledRattlesnake
New Mexico Ridge-nosed Rattlesnake, Crotalus willardi obscurus

A young Blacktailed Rattlesnake from the southeastern mountains of Arizona. When they are this age, they’ll often have subtle grey and black banding in the tail. This usually darkens to a solid black with age, but not always. Of the species of rattlesnakes in the state, coming across babies of this species out and about may be the least frequent for me.

A Western Diamondback Rattlesnake in ambush in a sandy wash on a very hot night.
This sand is much cooler than the surrounding rock, with smaller particles that lose energy more quickly. While it’s easy to think of reptiles as ectotherms always looking for sources of heat, they’re just as often looking for ways to lose it. Thermoregulating is more like a behavioral thermostat, and areas like this help.

One of the eyelash vipers we found on a family vacation to Costa Rica a year ago. It spent days in almost the same spot, only making a short move in the daytime to move under the nearest clump of moss.

An Arizona Ridgenosed Rattlesnake from the southeastern corner of the state. This is also our state reptile.

Quiz time: This subspecies of ridgenosed rattlesnake is only found in Arizona and Mexico. There are two other rattlesnakes that are also only found in Arizona and Mexico. What are they?
cerastesA Sonoran Sidewinder that had just crossed a road west of Phoenix. These small specialist rattlesnakes are abundant in the right conditions. This is the reason that hikers will almost never come across one … the flat sandy habitat they need is nobody’s hiking destination.

Leavitt, D. J., & Grimsley, A. A. (2019). Density, recapture probability, biomass, productivity, and population structure of Sidewinders (Crotalus cerastes) in the Sonoran Desert of Arizona. Herpetology Notes, 12, 427–435. https://www.researchgate.net/publication/332802062
A young Arizona Black Rattlesnake resting outside its den, where several larger adults have yet to emerge for the day. In time, it will darken and its pattern will fade to be the familiar dark black with yellow bands common in the region.
This same little snake, a year prior and a lot smaller, was what first gave this spot away as a rattlesnake den. Females stay at or near winter dens all year to give birth there, so a chance sighting of a neonate in August was an indication there was more to be found. Since then, I have found dozens more Arizona Black Rattlesnakes, as well as Western Diamondback Rattlesnakes and Blacktailed Rattlesnakes sharing the same den.
