Monday, July 5, 2010

Timber Rattlesnakes

 This impressive snake is the Timber Rattlesnake (Crotalus horridus). Don't you just love the species name? Horridus? Hinting at how horrible this snake has the potential to be? This is one of five venomous snakes in Missouri. The other four are the 1.) Western Pgymy Rattlesnake (Sistrurus miliarius streckeri), 2.)Eastern Massasauga Rattlesnake (Sistrurus catenatus catenatus), 3.) Osage Copperhead (Agkistrodon contortrix phaeogaster), and the 4.) Western Cottonmouth (Agkistrodon piscivorus leucostoma).

The timber rattler in the first picture was photographed a few weeks ago at a farm we own. It was approximately 3 feet long and had 5 rattles. It was very calm and showed no signs of aggression. We could only manage to make it rattle when I reached down and touched it's tail. We watched it for about 45 minutes and I managed to get 70 pictures of it. She slithered away to hide under a pile of wood. Once she was safely hidden she started rattling. We found that rather odd, and assumed it must be a nervous reaction to us bothering her.

Scientist are finding out that these snakes are not rattling to warn of their presence. They instead remain hidden and quiet. To rattle is to advertise your presence and ultimately leads to your death. In parts of Oklahoma where these snakes are harvested during rattlesnake roundups field tests were done, and the results  showed that the snakes in areas that were heavily harvested were mostly silent. In areas where little to no harvesting is done, they rattled more often. This could indicate the evolution of a more silent rattlesnake. They are certainly adapting and learning to change their ways. The rattlesnakes developed the rattle to protect them on the great plains from being stepped on by great hoofed animals like buffalo. Now this rattle is a calling card to death.

The timber rattlesnake is the largest of all the venomous snakes in Missouri, reaching lengths up to 5 feet. The largest recorded specimen in Missouri was 47 inches long. The all time record for this species is one recorded in Alabama, at a length of 6 feet 2 1/2 inches and weighing in at 5.5 pounds. That would be one seriously large timber rattler. They are a thick bodied snake and often times have a girth the size of a grown mans forearm. These are a beautiful snake, and they are highly variable in their coloration. They can have a base color of yellow, gray, tan, or brown with dark brown to blackish markings. The markings are like bands or v-shaped lines along the mid-body. Often there will be a rust colored dorsal stripe running the entire length of the body.The tail is black. The top of the head is gray, light tan or yellow and unmarked. As with all pit vipers they have deep pits on either side of their head. These pits are sensory pits and used to hunt prey. They feed on mostly mammals, but will also eat birds, frogs and other snakes. While they are capable of eating other venomous snakes they typically eat garter snakes. These are potentially one of the most dangerous venomous snakes in North America, largely due to their very large fangs and copious amounts of venom. Thankfully they are generally mild tempered and usually give plenty of warning before striking. The one pictured below that is very well camouflaged was found on our farm in Fillmore Missouri. Last year my husband and I were there so I could do some bug hunting. We are aware that rattlesnakes reside on this farm and were being very careful as we walked through the tall grasses. I walked by a tree that had a small pile of yellow limestone rocks near it. It looked like a good spot for a snake to sun itself after a cool night like we had the night before. I noticed nothing. My husband walked right behind me, and said "There is a snake" I turned around and noticed he was pointing to the rock pile I was just near. I went back to the pile and sure enough there was small timber rattler laying in the grasses near the rocks. These snakes have amazing camouflage. I walked within 2 feet of him and never spotted him. He was about 2 feet long. Joey got a stick and gently nudged him so we could see where his head was, and it took off behind the tree and disappeared. He showed his head for about 1.1 second, certainly not long enough to get a picture. I at least got a picture of how cryptic their coloring is, and I found out how very easy it is to walk right past one and not know it is there. He did not rattle at any time, nor did he show any aggression.

 Unfortunately these snakes are in sharp decline in much of their range, and have disappeared entirely from numerous counties throughout Missouri. Largely this is due to loss of habitat and persecution by people who fear being bitten. They are state protected and should be left alone. While I would not want to find one in my back porch, I certainly can appreciate them in the wild where they belong. I often try to educate people about their importance to an ecosystem and that losing them could cause untold amounts of devastation. Fear of snakes is so deeply rooted in many people that they feel the only good snake is a dead snake, and this tends to be doubled when it comes to the venomous variety. I could find no records of any deaths in Missouri due to this snake or any other venomous snake. UPDATE: I have since learned of a recorded death in 1933 due to this species. Apparently there is no other deaths attributed to this species. It is difficult to gauge an exact tally of deaths due to venomous snakes before the 1960's as records were not kept. Instead deaths of this nature were lumped together as poisonous reactions and could be anything from bee stings, wasp stings to snake bites.  Many bites occur in men ages 18-25. My guess is alcohol is involved. If you are inebriated, and out messing with a creature that you KNOW has the potential to bite and kill you, you deserve to be bitten! Leave them in peace and they will leave you alone. Above all else, if you want to see one of these snakes in the wild, leave the alcohol at home! However the biggest majority of bites actually occur when someone tries to kill the snake. The best option is to leave the snake alone. If you are in a situation where that is not an option then try to find someone who is capable of relocating it. Killing the snake should always be a last option. In the United States there are less than 10 deaths a year attributed to venomous snakes, you are far more likely to die of a dog bite!

Often times people ask me how to age a rattlesnake. The tail grows a new rattle each time it sheds, but this is not an accurate indicator of age as the snake may shed up to 3 or 4 times a year depending on how plentiful food is. Often times rattles get brittle and break off or they become damaged and fall off. 

I am working with a professor of herpetology at MWSU in St. Joseph doing a rattlesnake study on our farm in Fillmore, MO. What we hope to learn from this study is:
1.) How many snakes are on this farm?
2.) Are they breeding and how many young are there?
3.) Where are they hibernating?
4.) How far are they traveling away from the den site?

It should be an interesting study, and will hopefully gain us much knowledge about these often feared and hated, but environmentally essential animals. We met Dr. Mills, and two of his students at the farm last week. We walked the farm for around 2 hours and were about to give up without sighting a single snake of any kind. As we headed back to the cars, my brother-in-law shouted that he found one. We went to investigate his find, and noticed there was a nice sized rattle snake hidden under a large rock. Dr. Mills pulled the rocks away and exposed the snake. It was about 2 1/2 feet in length, and once again did not rattle. Not even when held down with a snake stick did it get irritated and warn us with that all to familiar Cicada-like noise of the tail. This one has 6 rattles and a button. The tail is visible in this photo below.

If one can look past their own fears, to the beauty of these misunderstood creatures, they would see an animal that is fascinating in its creepiness and beautiful in its lethalness.