In this sss-cintillating guest blog, photographer John Cancalosi delves into the fascinating, communal behaviors of timber rattlesnakes in Pennsylvania and Maryland. Through years of intimate observation and photography, Cancalosi reveals their complex social interactions, offering readers a unique glimpse into the lives of these often-misunderstood reptiles.
Text & images by John Cancalosi
A Lifelong Passion
Being a snake lover since early childhood, and a widely traveled wildlife photographer as an adult, it should come as no surprise that I have spent years photographing them. It IS surprising that fate brought me back to photograph snakes in the mountains of Pennsylvania and Maryland where I began my life and my affinity for these fine reptiles. Here my workplaces or “offices” are timber rattlesnake communal birthing sites known as “rookeries” where residents lead a surprisingly social existence.
Communal Birthing
There are two basic color morphs, yellow and black that mix harmoniously. I have seen as many as 40 pregnant females together at one site. They are living incubators, keeping themselves at the optimum temperature for their young to develop inside their bodies. Depending on the conditions, they either bask alone or form piles of serpentine spaghetti to help them keep their “ovens” at the right temperature. If it is too hot or too cold, they retreat to the shelter of their nearby rock refuges. Large groups presumably provide some protection from predators and there are likely other social benefits from such aggregations that aren’t fully understood. The young are born alive in late summer, and the “pups” stay in the company of their mothers and other adult females for 10-15 days until they shed their skins for the first time. DNA studies have shown the rattlers at the rookeries tend to be closely related. Because females only breed every three years or so, there are different groups in attendance every year.
Social Interactions & Communication
Although many question whether rattlesnakes have intelligence or emotions, after years of observing them, I would say that they have both. Of course, they are famous for telling us to back off with their rattles. In this case, there can be no mistaking their message. In other contexts, however, rattlesnakes don’t reveal themselves in human ways though facial expressions, or vocalizations. Instead, they use other means of communicating, such as laying down chemical cues in the form of scents that other snakes detect and follow. I have seen these gregarious serpents intimately entwined not only with other rattlesnakes, but also with garter snakes and copperheads. They appear to be coming together by choice rather than necessity, because there are plenty of basking sites. On other occasions I have seen them in less cuddly moods; a pregnant female flicking off a newborn crawling across its head, or adults shrugging off other adults that came too close. Once I saw a whole group of snakes “run” for cover when a raptor swooped low. It is doubtful that all the snakes saw the potential danger. Most must have been taking their cues from those that did, which is another form of social communication.
New Discovery
Recently, while going through video footage that I’d taken at a rookery in Maryland, I observed an interesting behavior that I didn’t notice in the field. I watched a pregnant rattlesnake vibrate her cheeks in a distinctive way while she was resting atop a copperhead’s neck. It lasted only a second, but the motion was strong enough to make the copperhead’s head vibrate as well. To see if I had missed this behavior on other occasions, I reviewed footage that I shot several years before at a rookery in Pennsylvania. Bingo! Again, a pregnant female did the same head vibration, this time on the body of a newborn pup, which appeared to change the direction that it was moving. I now had two examples of this fascinating behavior from two sites in different states! When I spoke to a well-known evolutionary ecologist, Dr. Gordon W. Schuett about this phenomenon, I found out why I never heard about it… it has never been reported! Could this be some form of subtle social communication? Hopefully more research will answer that question. Dr. Schuett and I plan to publish a scientific note on what we are calling “head muscle quivering”.
Habitat Challenges
During the two plus decades that I have visited one rookery in Pennsylvania I have experienced a lot of adventures. I have seen a progressive growth of the understory which has made it harder to reach my sacred site, a lichen covered sandstone slab where pregnant females congregate. I could cut a trail through this brush, but I don’t want anyone to find the site. I prefer to travel like a local bear, just bumbling my way along. There are faint trails at points, but I sometimes lose these and find myself bashing through thickets of mountain laurel, known affectionately in the south as “laurel hells.” To my credit, I always found the site even when my GPS stopped working. Fortunately, what I lack in directional skills and technological aids, I make up with sheer determination. The bears must have a good laugh at the same stupid human shin-smashing, camera-dumping and somersaulting his way through the forest year after year.
The gradual increase in forest vegetation isn’t just a problem for me. It also cuts off the precious sunlight that the rattlesnakes need to warm their bodies. Widespread clearing or burning could easily give the snakes the light that they need. However, a recent study showed that a more open canopy subjects rattlers to more avian predation, of which I have seen plenty of evidence. Besides the raptor-fleeing snakes described earlier, I have seen other snakes bearing dramatic scars from raptor encounters. Because of the trade-off of light versus predation, proper habitat management for timber rattlesnakes is a fine balance between open and closed canopy which can be attained only through site-specific, finely targeted clearing and or prescribed burning.
Coexistence and Respect
These snakes are large, possess potent venom and hence are one of the most dangerous snakes in North America. However, contrary to popular belief, they prefer to be left alone. When I am with them I am far more worried about me disturbing them than the other way around. Since they can be long-lived, up to fifty years or more, I would like to think that they might even recognize me given the time that I have spent in their company. They don’t do anything in a hurry and in order to photograph them you need to slow way down and be happy with your own company and the company of insects. While whiling away the hours waiting on the snakes and the weather to cooperate, I devote time to nourishing the local mosquitos and gnats which are a constant presence. I have involved my son in this project since he was very young. I took him with me, clad in hockey shin guards and he valiantly stayed for days, braving the rugged conditions. I gave him the camera and tripod once and he proceeded to take photos that won him a prize in the prestigious British Wildlife Photographer of the Year competition, at the ripe old age of 6!
Courting and Combat
For years all of the observations and photography at my rookeries were of females and their young. That all changed two weeks ago when a group of males came to “town” at my favorite Maryland site. Suddenly, there was love in the air and courtship abounded. The males jerk their heads up and down the bodies of the females in distinctive fashion while their tails wrap around the female’s tail hoping for consummation. After bouts of intense activity, the males often move a short distance away to take a break in the action. The females remain aloof and unmoved and this courtship can go on for days unrewarded. One female I watched gave herself away and followed the male as he moved further and more forcefully away than normal during one of his “breaks” and lured him back to their original courtship spot, a location that will have other significance later in this story.
There is a spot near the top of the rookery that I call “action central” because it is a preferred basking and sheltering site for both rattlesnakes and copperheads, While filming a courting couple at “Action Central” I noticed a huge, spectacular, yellow male, cruising purposefully across the boulders below. He zigged and zagged across the rocks constantly tasting the air with his tongue. He seemed to be working his way in my direction. He then disappeared under the boulders for fifteen minutes or so and I focused my attention on my original subjects. Then he suddenly appeared and the formerly amorous male moved off instantly thirty meters or so to a spot that he occupied for the next couple of days. Meanwhile “Old Yeller” began courting the same female. When I returned the next day, he and the female were still at “Action Central” when something amazing happened! Without warning, a modestly sized black rattler moved in from above and he and “Old Yeller” entered into intense combat! What the black snake lacked in size, it made up for with heart. They coiled their bodies and began an S – shaped wrestling competition, pushing and shoving each other across the rocks, eventually tumbling down the hill, out of sight.
Filming male combat in rattlesnakes had been my holy grail for decades. How did I respond when this scene magically unfolded directly in front of me? First of all my jaw dropped to the ground and next I started fumbling with my camera and cursing the fact that I didn’t have the right lens on. Fortunately, I was lucky enough to get some nice footage in the few minutes that I had before they dropped out of sight. What a magical experience, well worth the wait.
Snakebite!
The last time that I visited the site there was a light drizzle, but it was to clear and make for ideal conditions, intermittent sun and clouds with temperatures in the 70’s. While I waited for the rain to let up, I surveyed the scene and saw what looked like the original, medium sized male at “Action Central”. (“Old Yeller” had moved out on my last visit, allowing the smaller male to reoccupy the sweet spot). I returned to the scene of the last courtship that I filmed and saw nothing. That was until I saw a small black snake move under a rock at my feet. Curious to know what that snake was, I turned the rock over…and Whammo!!!…I knew exactly what happed…Snakebit!!!
At that point I paused, to ask myself how someone who had been photographing the many rattlesnakes and copperheads in this area for years and has enough intelligence to tie his shoes, could stick their hand under that rock. My answer to myself involved several obscenities that can’t be repeated here. In any case, having turned the rock carelessly and received the consequences, I needed to act. Was it a rattlesnake or copperhead? I hadn’t seen a thing, so I turned the rock over more carefully and saw a large adult copperhead staring at me. My attention now turned to my thumb, which was oozing blood from a (fortunately), single fang mark! While I sucked my thumb, I decided what to do.
My first thought was to keep photographing since many bites are “dry bites” where no venom is injected. I wisely chose to not stay on site after a few minutes of debate. Then, I looked up copperhead bite on my phone and the first article that I saw said to get to the hospital pronto! Based on the experience that I had with a rattlesnake bite as a teenager, I wanted to avoid that option. I walked the mile or so to the car quite comfortably. I had an ace up my sleeve: I would call none other than one of the leading experts on copperheads, my coauthor on the paper previously mentioned, Dr. Gordon Schuett! What did Gordon say?… Go to the hospital! Isn’t it possible to tough it out at home and avoid the problems associated with hospitals I asked? Turns out that he is a veteran of 14 venomous snake bites, only one of which landed him in hospital. Music to my ears, and with his coaching I drove the hour back home with no pain or problem other than the traffic. Then the honeymoon period ended and the pain set in and my hand swelled to the size of a boxing glove over the next couple days. Staying calm and resting while keeping the arm elevated as well as cautious use of ice is my treatment plan and after five days, I may be ready to hit the field tomorrow, this time in a less rock-turning mood.
Secret Snake Behaviour
No two days are exactly alike at a rattlesnake rookery. There is always some quirk in the weather or behavior that keeps things interesting. Things can start boring and suddenly the snakes reveal another hard-won secret. Such was the case this August at one of my Maryland rookeries. The day started with a single large snake, that I believed to be male, coiled under the overhanging rock at Action central. From its milky blue eyes, I saw that it was “in shed”, which is a period when they lay low for the most part, so I wasn’t expecting much action. Then the sky darkened and the first of three rainstorms moved through. I believe that crafty serpent was not positioned by chance. Most of his body was sheltered, but as the rain ran down the sloped, slick rock in front of him, he began drinking copious amounts of life-giving water off of the rock itself, the lichens covering the rocks and even his own body. These imbibing sessions are crucial for a snake’s survival in an area with no permanent surface water.
Seasonal Movements and Winter Habits
As winter approaches the snakes leave the rookeries and move to nearby overwintering sites. The young usually end up overwintering in the same places as their mothers or close relatives by following the scents laid down by the adults. For whatever reason, prior to retreating underground for the winter, timber rattlesnakes have been observed out late at night in October around the entrances to their wintering sites, bathed only in moonlight. Once they make their final descent, they wind down metabolically and remain subterranean for the next six months or so before emerging the following Spring to resume their above ground lives.
Conservation and Future Hopes
There is reason to believe that many of these Timber rattlesnake rookeries and winter dens may be used for hundreds or even thousands of years. Unfortunately, they now face increasing pressure from humans in the form of development, wanton killing, collecting and road mortality. The sheer remoteness and rugged nature of these places protects them to some extent. However, they need our help in terms of proper habitat management, increased public awareness and appreciation as well as enforcement of existing laws protecting them. These regal reptiles and the places that they inhabit have become sacred to me and it is my ardent hope that they will survive for many centuries to come.
