Sometimes field work doesn’t always go as planned. Snakes can actually be incredibly difficult to find. In June 2019, I (Rhett Rautsaw, PhD student) traveled to southeast Arizona to learn this lesson…again.
The goal of my trip was sample venom and blood from three rattlesnake species which are only found in the mountains of Arizona and Mexico. The species I was after are the Rock Rattlesnake (Crotalus lepidus), the Ridge-nosed Rattlesnake (Crotalus willardi), and the Twin-spotted Rattlesnake (Crotalus pricei). For my dissertation, I am looking to test whether a famous evolutionary theory known as character displacement extends to venom. The theory goes like this…when two species live in the same place, they will evolve divergent traits in order to avoid competition over resources (like food). When the two species live in separate places, they will evolve very similar traits since there is no competition. In southeast Arizona and northern Mexico, there is a mountain range containing each unique combination of these three species. The Santa Rita and Huachuca Mountains have all three species present, while the Pinaleño mountains only have Twin-spotted Rattlesnakes, the Patagonia Mountains only have Ridge-nosed Rattlesnakes, and the Hatchet Mountains only have Rock Rattlesnakes. Don’t worry, there’s also mountain ranges for all other possible combinations of two as well.
My trip began with a flight to Arizona and meeting up with Parkinson Lab’s newest graduate student, Tristan Schramer, and University of Michigan Ph.D. student, Taylor West. Tristan and Taylor are always posting great science/snake education on Twitter/Instagram, so you can follow them @Natricine_Nerd and @WildWildTWest.
We started in the Santa Rita Mountains just south of Tucson. We stayed with a good friend and fellow herpetologist – John Murphy (thanks John!). We were here for several days hiking the trails up and down the mountain. Unfortunately for us, we quickly learned that the rainy/monsoon season that normally brings the snakes crawling out of their hiding places would not be coming early this year. No matter, each day we continued to hike up steep mountain trails, flipping and replacing rocks and logs looking for hiding snakes. The hike up to Mt. Wrightson was a 5 mile hike up 4000 feet in elevation, but still no luck finding snakes. It was just too dry, but the views at the top of the mountain were spectacular.
However, the Santa Rita Mountains didn’t leave us empty-handed – unlike many of the mountain ranges to follow. After several more hikes through the canyons and hillsides, we were able to find some beautiful Mountain Kingsnakes (Lampropeltis pyromelana knoblochi). Not our target, but a nice surprise given that these snakes are not easy to find.
The kingsnakes provided us with the hope that we needed. By the end of our time in the Santa Rita Mountains, we found 3 gorgeous Ridge-nosed Rattlesnakes. Ridge-nosed Rattlesnakes – along with both Twin-spotted and Rock Rattlesnakes – are protected in the state of Arizona because they are frequently poached and their limited distributions on the mountains make the vulnerable to extinction. All of my research (permitted by Arizona Game and Fish) is catch-and-release to ensure I do not harm any populations. We collected the snake, milked it’s venom, drew blood, measured the snake, and released it back exactly where we found it.
After the Santa Rita Mountains, we headed to the Patagonias. Sadly, we didn’t have any luck here finding rattlesnakes, even after several days of searching. We did find another baby kingsnake wedged deep in a rock crevice. Next, we headed to the Huachuca Mountains where we camped at about 7,000 ft elevation and hiked the surrounding areas. From our campground we hiked up to Carr Peak looking for Twin-spotted Rattlesnakes, but still no luck. Although we did find a bathtub near the top?
Feeling worn down and defeated, we got ahold of the Huachuca Area Herpetological Association (HAHA) and they gave us some great advice for places to look. We ended up finding two more kingsnakes along with a single (beautiful) Ridge-nosed Rattlesnake and Rock Rattlesnake (Crotalus lepidus).
After the Huachuca Mountains, we headed north to the Pinaleños. We only spent a couple days here, but we had no luck finding our target Twin-spotted Rattlesnakes. Frustrated, we left for Tucson and searched the lowlands for fun. We were able to find one of the coolest rattlesnake species (biased opinion) – the Sidewinder (Crotalus cerastes). These snakes are difficult to catch because their movement is nearly unpredictable! Recently, our lab has published a couple papers on Sidewinder venom variation (or lack thereof). You can check out the papers here and here.
We ended our trip with The Biology of the Pitvipers 3 Meeting in Rodeo, New Mexico. Most of the rest of the lab met Tristan, Taylor, and I out there and we picked up Dr. Parkinson from the airport. At the meeting, myself, Erich Hofmann (Ph.D. Student), Erin Stiers (M.S. Student), Matt Holding (Postdoctoral Parkinson Lab Alumnus), and Dr. Parkinson gave presentations while Jason Strickland (Postdoc), Andrew Mason (Ph.D. Candidate), and Miguel Borja (Visiting Scientist) gave poster presentations. In addition, Dr. Parkinson’s first Ph.D. student Dr. Todd Castoe was also attending the meeting (see lab-family picture below). Overall, although field work was rough and we didn’t find many snakes, it still turned out to be a great trip.
Number of Miles Driven: ~2,000 miles
Number of Miles Hiked: ~100 miles
Hiking Elevation Gain: ~18,000 ft
Rocks flipped: countless, but probably less than Erich on his Africa trip
Number of times my cot fell out from underneath me while I was sleeping: 4
Number of love ballads sang with modified lyrics to try and draw snakes out of hiding: 5
Number of lizards caught to make ourselves feel better about our love ballads not working: ~20
Number of “good luck” packs of twin-snake gummies eaten: 5
Number of “good luck” Circle K Polar Pops drank: a lot
Number of “good luck” jackalope antlers found: 2
Amount of actual luck actually achieved by any of the previous methods: 5 snakes