Thursday, July 16, 2015

World Snake Day

To celebrate World Snake Day I thought I would share with you one of my personal favorites, the black rat snake (Pantherophis obsoletus). This particular species is the most widely distributed of all rat snakes in the United States. They are found throughout the Eastern United States, west to Texas, Lousiana, and Mississippi and north into small portions of Southern Canada. In Missouri this is probably the most commonly encountered snake we have, second only to garter snakes. They are found in a wide variety of habitats from rocky hillsides that they share will timber rattlesnakes, to farmlands, backyards, parks, prairies and woodlands. Of these habitat occurrences woodlands is the preferred home of these snakes. They adept at climbing and are often seen high in trees.

Their diet is highly variable, and includes rats, mice, voles, bunnies, birds, and bird eggs, including chicken eggs, which has earned them another common name of Black Chicken Snake.

I've often heard blue jays and other birds raising a loud ruckus in the trees and when I investigate I almost always see a black snake causing all the commotion. I've witnessed on more than one occasion birds pecking at snakes trying to protect their eggs and nestlings from being eaten by this hungry predator. I also know these snakes will frequently invade bird houses for the eggs and nestlings hidden within. While this can be very upsetting to those who love birds and who invite birds into their yards by feeding them or providing housing. I personally find it hard to be mad at the snake. They are only trying to survive and find food like any other animal, and when that food presents itself in such an easily accessible location as a bird house how can we fault the snake for doing what instinct drives it to do? We also raise chickens and once in awhile we encounter a black snake within the nesting boxes feeding on the eggs. Generally we are drawn to the chicken coop by loud clucking and panicked commotion going on inside the coop. I remember a couple of years ago my husband (who is not a fan of snakes) came and got me and told me he needed my help.

I followed him to the hen house and he pointed to a nest box. There was a gorgeous black rat snake feasting on the chicken eggs. I found the situation a little humorous, much to my husbands irritation who just wanted the snake gone. I picked up the snake and placed her outside, after snapping a photo. As soon as I placed her on the ground she turned around and slithered right past my husband and straight into the hen house again!! She disappeared into a crack in the wall inside and wasn't seen again. My husband just looked at me and rolled his eyes and said "Well, that was helpful!"
I'm sure the snake was hanging out in the hen house after the mice who hang out there feeding on the chicken feed. Once in the hen house it discovered the eggs and decided that meal was much easier to catch than a nervous, fast moving mouse that fights back by biting.

Black snakes, like all snakes hibernate over the winter and will often use hibernation sites occupied by rattlesnakes and copperheads. This communal hibernation habit earned them another common name of Black Pilot Snake, because it was believed by many that the black snake led, or piloted, the copperheads and rattlesnakes to the hibernation den. We of course know this is not true, they simply share the same locations.

Several years ago black snakes began using a crawl space in our basement for a hibernation site. Each spring I remove from 5 to 8 black snakes, yellow-bellied racers and garter snakes from the basement and put them outside. I assume they get turned around when trying to find their way back outside and end up in our laundry room where the opening of the crawl space is located. It is not unusual for me to be doing laundry and find a snake peeking back at me.

It is also rumored that black snakes will eat rattlesnakes, and there are videos on the internet claiming this to be true. Black snakes are not known to favor eating other snakes and the video's in question are showing black kingsnakes or indigo snakes which choose snakes as their primary food source. Another rumor involving rat snakes and rattlesnakes is that they will cross breed and create hybrid offspring of both species, this simply is not biologically possible. They are too far removed on the evolutionary scale to accomplish something like that in natural settings.

Black snakes mate in the early spring and lay their eggs sometime in June or July. They often share the same location as other black rat snakes to lay their eggs, creating a rookery of many different clutches. I have such a location in my back yard. Many years ago we cut down a large maple tree that was in danger of falling on our house. We used the stump for many years as an over-sized planter until eventually it began rotting away to such a degree that we could no longer plant flowers in there. Bugs had worked on the stump and it was in an advanced stage of decay. It was at this point it seemed like a preferred site for black snakes to use for a place to lay their eggs. A few years ago I noticed two black snakes laying their eggs under the loose soil around this stump. Two months later I noticed a shed skin of a baby snake on the stump and wondered if the snakes were beginning to hatch and emerge. I dug around in the dirt and found the eggs and they were indeed hatching. Imagine my excitement to witness something like that!!!

All told there were 57 babies that hatched from those eggs. That sounds like a lot of baby snakes, but only about 10% of those babies will survive. While snakes are excellent predators they are also prey for many animals. Foxes, raccoons, coyotes, other snakes, birds and even your house cat will all eat snakes. Juvenile snakes tend to be much more defensive in their behavior and much more apt to bite when faced with a predator, including a human who may want to capture one. This super defensive behavior is in response to the fact that when you are a baby snake everything wants to eat you.

Juvenile rat snakes look entirely different than they do as adults. As juveniles they have a gray or brownish background color with darker blotches or spots along the length of their body. This acts as camouflage to protect them to some degree from predators. The pattern breaks up their shape making them harder to see. Some even speculate that it is also a form of mimicry, because they superficially resemble rattlesnakes. If you look like something venomous it could be assumed a predator might think twice about trying to eat you.

 A couple of weeks ago I discovered the stump was being used again by the black snakes. This time I counted 7 females using the stump over the course of a week all laying eggs. One night there were three snakes at once laying eggs. I was fascinated by them and sat by the stump for over 3 hours watching them. 
Short video of black snakes in the stump.

If two snakes from a few years ago succeeded in leaving 57 or more eggs, I can only imagine the amount of eggs that 7 snakes will leave behind. If they average 20-25 eggs per clutch that's a lot of babies! 

  Predation by animals is not the only thing snakes have to fear in the struggle to survive. Humans are notoriously prone to kill snakes and I've heard uttered on more than one occasion by intolerant people "the only good snake is a dead snake!" This attitude frustrates me and even angers me to some degree. Snakes are excellent rodent control and we all know rodents carry diseases. Just Google Hantavirus! Not to mention rodents are host to ticks which spread many types of deadly diseases to humans and our pets. Snakes help control those disease by controlling the rodents.  Roads and deadly drivers also take a huge toll one snakes. Rodents are also estimated to be responsible for up to 30% of house fires, caused from their habit of chewing on wiring. 

I know many drivers go out of their way to run over snakes, I've witnessed people purposely crossing the dividing line on a highway to run over a snake. Not only are they risking an accident, they are killing an innocent animal using the road as a basking location or as means to get from one location to another. Did the snake deserve that? 

Humans also use glue traps to catch rodents, bugs, spiders and even snakes in their homes. These traps do not kill their captors quickly, instead the animal dies a slow agonizing death by starvation. They cannot move or escape, and they feel fear, hunger and thirst before perishing. These traps are cruel and in my opinion should not be used.
Several times a year people will bring glue traps into my office with a still alive snake attached to it wanting me to ID the snake. Their fear is often that the snake is venomous. So far there has never been a venomous snake brought in, nearly always it is black rat snakes. Once the person leaves I spend sometimes as much as an hour painstakingly and gently removing the snake from the glue board. This involves a lot of dawn dish soap, Avon Skin-so-soft and patience. Once removed then I release them in the timber behind our building.

Another problem is litter. Humans are very messy creatures and we often leave behind trash that we don't give a second thought about. As evidenced by the following pictures. My daughter found this young black rat snake near our back door three years ago. It had somehow slithered through a piece of PVC pipe when it was a juvenile and became stuck. We know we had hired a plumber a few years prior to this and we assume the plumber left behind some small pieces of PVC that he had cut, then the snake unwittingly found them and carried this bracelet around with it for quite some time. Had we not found it when we did, it most likely would have died. My husband helped me and we sawed the plastic off which took about 30 minutes and resulted in the snake biting me, but we were able to release the snake.
Over the years I've often wondered what became of this snake and if it survived and that question was answered this year when I found those snakes laying eggs by the stump. One of them had the tell-tale scar from the PVC pipe it had once worn. I was so happy to know that snake had not only survived, but thrived and went on get bred and leave behind her offspring. She is a true survivor.

Here is the snake with the PVC pipe scar 3 years after her ordeal. 

When I was a kid every black snake we encountered was glossy black with a white belly. That isn't so much the case anymore. I find snakes with red, yellow, white and some orange coloration between the scales and a strong pattern visible more often than not now. This coloration varies from a lot to a little depending upon the specimen and the location. The ones at my house seem to have a lot of color, whereas other locations only a small amount. But I have not seen a completely black black rat snake for many years.
I'm not certain what this color change indicates, or why it has been happening over the past few decades. Is it an adaptation for future survival? Is it a fluke of breeding that produced this color and now breeding is selecting for this as a dominant feature? I don't have the answers, but I can attest to the fact that they are different now.
Notice the red and white coloring between the scales
Many people fear snakes and this fear usually comes from well meaning adults telling children that snakes are nasty, dangerous or will bite. While it is true that a snake will bite, but that is no reason to fear something. Most any animal will bite if threatened or afraid and it cannot escape. Bites happen when we try to handle the snake, or accidentally step on one or inadvertently put our hand on one, like in the hen house when gathering eggs. These bites are not offensive, they are DEFENSIVE. Snakes will not chase you down with the intention of biting or harming you. Snakes are not nasty, vile creatures. They aren't known to spread disease, instead they help control animals that do. The only snakes that could be considered dangerous are the venomous variety, and once again bites only occur when the snake is protecting itself or if you accidentally touch one or step on one. Bites are rare by these snakes, and death is even more rare. We should strive to be more tolerant of all wild animals, especially snakes. They are our friends and provide free rodent control.

1 comment:

  1. I have been startled coming upon them in a crawl space, and laugh at myself since we both were in fear.I would like to see where they lay eggs.