Friday, September 6, 2019

Zombie Lizard and "Hearty" Snakes!

Yesterday my colleague Dr. Charley Knight posted a photo of a "zombie" lizard to Twitter, which I retweeted, then posted to Facebook, where it quickly went viral. The photo shows a short-horned lizard (Phrynosoma hernandesi) on Mt. Lemmon in Arizona that is missing the skin and muscles along one side of its back, such that its ribs and internal organs are exposed.

I initially assumed it was dead, but on further inspection of its posture (as well as Charley's post saying it was "scampering about") I realized it was actually alive. It had likely been captured by a predator, perhaps a bird, that ripped off its tissue but dropped it.

What is the prognosis for this lizard? Well, as many have conjectured online, it may have been alive when observed, but would likely be dead soon.

This got me thinking. Why do we assume that this lizard won't make it? The answer is that we inevitably think about what we happen if WE were subject to a predatory blow that removed our skin and muscle, exposing our organs. We would certainly die rapidly, if not from infection then from dehydration.

But a reptile? In my opinion, if it could survive the loss of water through the wound, it actually could potentially heal and survive such a gnarly injury. Why? Because reptiles have crazy immune systems that we are just beginning to understand.

The evidence I have for this comes from the many reptiles I have seen in the field who are alive despite having incredible scars or wounds that should have killed. Many people reported similar observations on the zombie lizard post on social media. Here are just a few examples of healed herps that I have seen.

This is Tripod, an adult male chuckwalla (Sauromalus ater) that my Herpetology class has recaptured at least three different years in the Mojave National Preserve.

Three-legged chuckwalla captured and released by permit from National Parks. Photo by Jason Wallace.

Tripod likely lost his leg when he was young, healed up nicely, and appears to be a healthy, dominant male.

Now check out Ecto, a subadult Desert Kingsnake (Lampropeltis splendida) that my Herpetology class found hit by a car on Foothills Rd. near the Chiricahua Mountains in Arizona. The car had apparently clipped him such that his chest and pericardium opened, with his heart beating away on the outside of his body (the technical term for this is a cardiocoel). Now you see why the students named him Ecto (and yes, they gave him a Twitter account).

I planned to humanely euthanize Ecto, but the students begged me to try to save his life. We gave him water and after he lasted through the night, we slipped his heart back inside his body, gave him antibiotics, sewed him up, and we took him back to California.

Ecto lived with a student in the class for almost three years, eating well and growing into a nice adult, before eventually dying. His owner took him to a vet for a necropsy and the cause of death was hyper-calcification of his pericardium, with the area completely surrounded by scar tissue from the injury years before. What a tough little noodle. (By the way, his owner took him back to Arizona to bury him where he was collected. Awwww!)

Speaking of tough noodles, this one might be my favorite. Years ago, my lab was conducting a radio-telemetry study on local Southern Pacific Rattlesnakes (Crotalus oreganus helleri). We found one of our large males with a huge wound across his underside, again possible from a bird like a raptor. When we anesthetized him, we discovered that the skin and muscle were completely ripped open, with the wound occurring just over the heart.


We gave him antibiotics, sewed him up, and let him go. We also removed his radio-transmitter, so unfortunately I don't know how he fared, but he was a big healthy snake and very likely survived.

I hope I've convinced you that these animals are absolutely incredible!