Gopher Snake!

[woodsorrel]

This is the rare case when I saw the snake before it saw me. Are there gopher snakes in the UK? I would think not because their peculiar behavior seems adapted to the US. This Pacific Gopher Snake (Pituophis catenifer) is five feet long:

The coloration of this one is unusual to my eye. I was 200 miles south of my home territory and this snake looks a bit darker than the ones near me.

Gopher snakes are constrictors that eat rodents, birds, eggs, insects and smaller reptiles. They are diurnal, so it is not uncommon to see them. I routinely notice them in grassland, mixed forest, and chaparral.

One of the most fascinating things about this snake is its defensive behavior. It looks very much like our venomous rattlesnakes. When it feels threatened, it becomes the master of impersonation. It coils like a rattlesnake and flattens its head to look like the pit viper. But that is not all! It shakes its tail back and forth to mimic the rattlesnake. The tail may rub on leaves to create a buzzing sound. The snake also hisses at an unusually loud volume. This hiss sounds much like the buzz of a rattlesnake. This snake would make a terrific poker player!

How can I tell that it is a gopher snake and not a venomous rattlesnake? The pupil in the eye is round and a “mask” runs across its forehead between its eyes, like a raccoon’s. It is just barely visible in the close-up picture.

What I find intriguing about this snake is its behavior. I can picture how the color adaptation would evolve over time. Snakes looking like rattlers would not be predated as often. But I can’t fathom how the behavioral mimicry evolved. What mechanism produces a snake that can mimic another so perfectly? It’s not like this snake graduated university. I find it simply amazing.

Are there snakes like this in the UK? Are there similar examples near you of behavioral mimicry?

- Woodsorrel

 

[Countryman]

In mainland UK we have only 3 species of snakes which are quite rare to see but In Ireland none at all.
We see Grass Snakes, Smooth Snakes and the Adder. We also have Slow Worms which look like a snake but are a legless Lizard.
Of these I believe the only one indigenous to Scotland is the Adder.
None of them, to my knowledge, do any mimicry.


Sent from my iPhone using Tapatalk

 

[Adze]

What mechanism produces a snake that can mimic another so perfectly? It’s not like this snake graduated university. I find it simply amazing.

Evolution. It's a numbers game. The ones which didn't sound like rattlers got eaten and didn't procreate as much as the ones which did.

 

[woodsorrel]

What you say makes sense, Adze. But I find it hard to believe that the first practitioners had the fully developed impersonation. So I wonder how the roots of the behavior could have kept them from being eaten. Maybe predators were dumber back then?

I guess it's also possible that a common ancestor had the behavior and then one snake kept it even though it was not venomous.

- Woodsorrel

 

[Toddy]

You could just as easily ask how the rattle snake grew it's rattle in the first place too
Which came first ? the venom or the rattle ?

cheers,
Toddy...who finds herself very glad that the only snakes she's ever seen in the wild in Scotland are adders and grasssnakes.

 

[mrcharly]

Could be parallel evolution rather than mimicry. 'puffing up', hissing, screeching are all common behaviours to deter attackers. Maybe both gopher snakes and rattlesnakes did this and the rattlenakes gradually evolved a 'rattle'.

 

[Adze]

What you say makes sense, Adze. But I find it hard to believe that the first practitioners had the fully developed impersonation. So I wonder how the roots of the behavior could have kept them from being eaten. Maybe predators were dumber back then?

- Woodsorrel

Not necessarily dumber... but some predators are definitely more cautious than others. In certain cases it's a great survival trait, witness the brown rat and it's reluctance to eat significant amounts from any one source.

Quite probably the earliest antecedents of the modern gopher snake didn't sound like a rattler's rattle... but those which sounded most like it fooled more predators, or at least fooled those predators more cautious than others and over time, a lot of time, the trait was reinforced in the offspring.

Not all predators of proto-gopher snake needed to be so easily fooled... as little as one predator species would probably be sufficient to give an advantage over competing proto-gopher snake species.

 

[JonathanD]

You've all got it all backwards, the Rattler is evolutionarily younger than the gopher snake. It all started with using the tail as a lure to attract prey. The gopher snake is less advanced than any viper, especially the pit vipers and rattlesnakes.

Now I'd be interested to see what conclusions people make based upon that

 

[Adze]

Ah... a popular misconception that evolution has ended and everything is already fixed.

Yes viperidae are a more recent development than colubridae, but the evolution of the two did NOT cease and still hasn't.

 

[JonathanD]

Quite right. So originally the tail was used as a lure to attract prey by primitive species like the gopher snake

Rattlesnakes use the same tail wiggle to warn predators off.

Gopher snakes, despite being evolutionary older than the rattlesnake, now use the tail as a deterrent to ward off predators.

But it's not even that simple, as vipers and even some colubrids and elapids wiggle their tails to look for anchor points to either aid in propelling the body forwards to strike or to back into vegetation. Defence and escape, all evolving with the same movements.

So did the primitive gopher snake develop the tail 'rattle' to ward off predators after finding it effective whilst using it as a lure for prey.... and then the rattler evolving the strategy from that? Or did the gopher develop the movement after hanging out with its rattler mates? Are constrictors and live eating colubrids the dead end of the snake evolutionary ladder, or are they still evolving and the catalyst for the viper evolutionary step forward?

 

[woodsorrel]

Wow, these are very interesting thoughts.

Many snakes seem to wave their tails when excited. But the Gopher Snake does much more than that. It flattens its head to look like a venomous snake. It coils like a rattlesnake. It also makes a loud hissing sound that is very similar to the sound of a rattlesnake's rattle. This strikes me as a quite complex behavior. It also just happens to resemble the rattlesnake in color and markings.

To me, it is fascinating that the snake has such a high quality act. I would love to have insight into the history that produced such an academy award winning performance.

- Woodsorrel

 

[Fraxinus]

This snake would make a terrific poker player!

- Woodsorrel

I almost spat my beer out!

Nice pics, btw, seeing as it is a constrictor does that mean it is harmless to humans?
I have a healthy dislike of snakes but I like gators and crocs....weird huh!

Rob.

 

[JonathanD]

Nice pics, btw, seeing as it is a constrictor does that mean it is harmless to humans?

A constrictor that size... yes. One this size... no.

 

[Fraxinus]

I hope he got belly ache I was under the impression that some constrictors have a venom too, or is that another hollywood myth propagation.

I have only seen a grass snake here in the UK, it was swimming across the River Medway in Kent while we were canoeing and raised its head to get a better look at us before speeding off to the other bank but saw two Adders (at least I am fairly sure they were) while working in the olive groves on Crete. Other than that my, self imposed distanced view, was at a place in Florida that had several species and a few demonstrations by a handler. While the speed of the Rattle Snakes strike was impressive, I hold a dislike of teasing an animal into aggressive behaviour with a balloon on a stick! (Maybe I don't dislike the snake as much as I think, or just not happy with bullies )

Rob.

 

[JonathanD]

I hope he got belly ache I was under the impression that some constrictors have a venom too, or is that another hollywood myth propagation.

A very small amount of venomous snakes can use constriction, but as a general rule constrictors are non venomous. Non of the python or boa family are venomous. That is Hollywood myth.

 

[Fraxinus]

A very small amount of venomous snakes can use constriction, but as a general rule constrictors are non venomous. Non of the python or boa family are venomous. That is Hollywood myth.

Cheers JonathanD, that was a heck of a quick reply, and appreciated.

Rob.

 

[santaman2000]

A very small amount of venomous snakes can use constriction, but as a general rule constrictors are non venomous. Non of the python or boa family are venomous. That is Hollywood myth.

I can't even recall a single film that ever portrayed them as venomous.

 

[santaman2000]

...... While the speed of the Rattle Snakes strike was impressive......

I believe I've heard that the fastest was the Bushmaster? JD could you confirm or correct that please?

 

[woodsorrel]

Nice pics, btw, seeing as it is a constrictor does that mean it is harmless to humans?
I have a healthy dislike of snakes but I like gators and crocs....weird huh!

Rob.

Yes, Rob, this snake is not a threat to humans. It can bite if provoked, but it does not do serious damage.

I don't find it weird to dislike snakes more than gators or crocs. Snakes have always made me uncomfortable. Yet, I have willingly walked within ten feet of a female alligator sitting on her nest. I can't explain it because it is not rational.

I have had several close encounters with venomous snakes in the US, and with their more aggressive relatives abroad. I find that if I learn about the particular snake, I tend to fear it less (most of the time). A herpetologist told me recently that fear of snakes did have an evolutionary purpose. It kept us safe from snakes that might hurt us. But what people feared were specifically the dangerous snakes. He thinks that with most people now it is "fear of the unknown." Since people spend much less time outdoors, there is a vacuum of knowledge. Without knowledge, fear of the unknown takes over. He does not dismiss that fear. But tries to educate people about snakes.

- Woodsorrel

 

[mrcharly]

But what people feared were specifically the dangerous snakes. He thinks that with most people now it is "fear of the unknown." Since people spend much less time outdoors, there is a vacuum of knowledge. Without knowledge, fear of the unknown takes over. He does not dismiss that fear. But tries to educate people about snakes.

- Woodsorrel

That makes sense to me. I grew up in rural western australia, in areas frequented by Dugites and Tiger Snakes, both venomous (tiger snakes particularly so and quite aggressive). Snakes make my flesh creep - but not so much constrictors and I've handled a largish python.

Dugites are pretty passive and I've walked (barefoot) within a couple of feet of them without much worry - they weren't displaying 'threatened' behaviour and I didn't threaten them. I wouldn't willingly walk within 10ft of a Tiger snake.