Interesting rattlesnake news

How well do rattlesnakes tolerate surgically-implanted transmitters?

As I have discussed before, there is a long (20+ years) history of telemetry studies of rattlesnakes in which individual animals tolerate the transmitters for years, enduring periodic surgeries to replace the radios. The animals thrive, repeatedly producing offspring and growing at the same rate as rattlesnakes without transmitters.

I bring this up because of a phone call last weekend from the landowner where I conducted my El Dorado County field study. He had just encountered the first Northern Pacific Rattlesnake I ever marked and telemetered, still identifiable by the yellow-over-yellow paint remaining in his rattle. He is now an exceptionally large male with twelve rattle segments – but in 2009, he was a young animal with a tapered unbroken rattle. He eventually endured four annual surgeries to implant and replace transmitters, followed by a fifth surgery in 2013 to remove his last radio.

Here is a PowerPoint slide of Male 01
Here is a PowerPoint slide I use to illustrate how marking the rattles helps to judge growth and shedding frequency. The photos are of my Male #1. It also demonstrates how the rattle breaks over time. According to my friend, the 2011 paint is now just two segments from being lost but the snake is big,  healthy, and thriving. You can see that, once the early tapered segments are gone, the rattle offers little insight into the age of the snake.

Male 01 being sighted alive and healthy is just more evidence that the surgical protocol and other study methods used by me and many of my rattlesnake-researcher colleagues is well tolerated by the animals we seek to learn more about.

Rattlesnake intelligence?

Despite my frequent admonition that we often tend to give rattlesnakes and similar animals too much credit for cognitive thought, friends at San Diego State University recently published some compelling evidence that rattlesnakes may learn from experience and apply those lessons to anticipate and mitigate problems during future similar circumstances. Bree Putman and Rulon Clark have spent years studying rattlesnake predation tactics by setting up video cameras on hunting rattlesnakes and recording their predatory encounters with small mammals. (This works because rattlesnakes are ambush hunters that sit still for long periods of time, waiting for prey to wander by.)

While reviewing 2000 hours of video, Bree and Rulon discovered two examples of rattlesnakes using their heads and necks to move foliage out of the way that might otherwise interfere with a strike when prey wanders close (click here for video). The animals involved were Northern Pacific Rattlesnakes – the same species as we have in the Sacramento area. Similar behavior has been reported a couple of times in the past, once involving a Prairie Rattlesnake (Crotalus viridis) and once involving an Arizona Blacktail Rattlesnake (Crotalus molossus); both these incidents were witnessed by observers but not recorded.

Thus, evidence continues to accumulate that rattlesnakes are likely more social and maybe more intelligent than previously thought – although many habits are undoubtedly genetically programmed by natural selection. The new report by Putman and Clark is contained in the current issue of The Southwestern Naturalist (volume 60, number 4; December 2015).

For more interesting videos of natural predatory behavior by rattlesnakes, go to Rulon’s YouTube page.

2 thoughts on “Interesting rattlesnake news”

  1. Amazing, I rescued three rattlers. Two western diamondbacks and a great basin. My male Western Diamondback has seemed to pick up on many things i tried to teach him. After six years of having him he follows my finger along the terrium glass to the hiding mouse he struck that got away and hid. He seems to know im guiding him to the food source via my finger, its amazing to watch but took along time for him to figure it out. He also would assume the strike posistion if i spooked him on accident, my response has been to put up both hands as if to say stop. Then i would approach the terrium glass while turning my head from him to the side as if i wasn’t afraid of him nor was i a threat. Amazingly after a few years of this i would pretend he spooked me, one time he was face to face with me through tbe glass and sneezed, scared the crap out of me.. but once he saw me jump back from being startled he did the same thing i would do, he suddenly turned his head away from me to the side and quit rattling. I set him up a few times and he did the same thing over and over just like i use to. Im not sure what it means but he surely has learned i dont want to be a threat. He now waits for me to come home then comes out of his cave to curl up against the terrium with me. ( They have a very large terrium that has seperate terriums with tubes linking them, one of those is next to my pillow hence he has alot of human interaction. The great basin i rescued for a pet store that ended up with it was just a baby but watched me and the male westerns interaction now seems to be just as tolerant of me and has caught on to alot of our interactions and repeats them. This is by no way formal or controlled testing but rather just the dumb things humans try with animals for no real reason but i still find it interesting to say the least. They seem to learn from experiance in the male westerns case and by sight from the baby great basin. Pretty neat. I grew up rescuing catching rattlesnakes as a kid and have even been bit three times at once and spent a few weeks in I.C.U. and have been fascinated with them ever since. I wish they were in the wild, i dont belieave in “pet” rattlesnakes but they are rescues so i have taken then in and given them an amazing home with many terriums and differant features they get to explore. I hate having them in captivity but at least they have a very good healthy interactive life. They also like watching late night t.v. very interesting creatures and im thinking there more intelligent then tbere given credit for.

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