Snakes on Our Barrier Islands

Snakes on Our Barrier Islands

Over the last two years I have been surveying snakes in a local community on Perdido Key.  The residents were concerned about the number of cottonmouths they were seeing and wanted some advice on how to handle the situation.  Many are surprised by the number of cottonmouths living on barrier islands, we think of them as “swamp” residents.  But they are here, along with several other species, some of which are venomous.  Let’s look at some that have been reported over the years.

The dune fields of panhandle barrier islands are awesome – so reaching over 50 ft. in height. This one is near the Big Sabine hike (notice white PVC markers).

In the classic text Handbook of Reptiles and Amphibians of Florida; Part One – Snakes (published in 1981), Ray and Patricia Ashton mention nine species found on coastal dunes or marshes.  They did not consider any of them common and listed the cottonmouth as rare – they seem to be more common today.  In a more recent publication (Snakes of the Southeast, 2005) Whit Gibbons and Michael Dorcas echo what the Ashton’s published but did add a few more species, many of which I have found as well.  Their list brings the total to 15 species.  I have frequently seen four other species in Gulf Breeze and Big Lagoon State Park that neither publication included, but I will since they are close to the islands – this brings the total 19 species that residents could encounter.

 

Leading us off is the one most are concerned about – the Eastern Cottonmouth (Agkistrodon piscivorous).  Though listed as “rare” by the Ashton’s, encounters on both Pensacola Beach and Perdido Key are becoming common.  There is more than one subspecies of this snake – the eastern cottonmouth is the local one – and that the water moccasin and cottonmouth are one in the same snake.  This snake can reach 74 inches in length (6ft).  They are often confused with their cousin the copperhead (Agkistrodon contorix).  Both begin life in a “copper” color phase and with a luminescent green-tipped tail.  But at they grow, the cottonmouth becomes darker in color (sometimes becoming completely black) while the copperhead remains “copper”.  The cottonmouth also has a “mask” across its eyes that the copperhead lacks.  Believe it or not, the cottonmouth is not inclined to bite.  When disturbed they will vibrate their tail, open their mouth showing the “cottonmouth” and displaying their fangs, and swiveling their head warning you to back off.  Attacking, or chasing, rarely happens.  I find them basking in the open in the mornings and seeking cover the rest of the day.  Turning over boards (using a rake – do not use your hand) I find them coiled trying to hide.  MOST of the ones I find are juveniles.  These are opportunistic feeders – eating almost any animal but preferring fish.  They hunt at night.  Breeding takes place in spring and fall.  The females give live birth in summer.  As mentioned earlier, they seem to be becoming more common on our islands.

 

Eastern Cottonmouth with distinct “mask” and flattened body trying to intimidate.
Photo: Rick O’Connor

This year, while surveying for cottonmouths, I encountered numerous Eastern Coachwhips (Masticophis flagellum).  These long slender snakes can reach lengths of 102” (8ft.), move very fast across the ground – often with their heads raised like a cobra – and, even though nonvenomous, will bite aggressively.  They get their name from their coloration.  They have a dark brown head and neck and a tan colored body – resemble an old coachwhip.  They like dune environments and are excellent climbers.  They consume lizards, small birds and mammals, and even other small snakes.  They are most active during the daylight, but I usually find them beneath boards and other debris hiding.  They have always been on the islands but encountered more often this past year.  They lay eggs and do so in summer.

 

Their close cousin, the Southern Black Racer (Coluber constricta) is very similar but a beautiful dark black color.  They can reach lengths of 70” (6ft.) and are also very fast.  Like their cousin, they are nonvenomous but bite aggressively – often vibrating their tail like cottonmouths warning you to stay back.  They are beneficial controlling amphibian, reptile, and mammalian animals.  They are also summer egg layers.

The southern black racer differs from otehr black snakes in its brillant white chin and thin sleek body.
Photo: Jacqui Berger.

There are a few freshwater snakes that, like the cottonmouth do not like saltwater, but could be found on the islands.  These are in the genus Nerodia and are nonvenomous.  There are two species (the Midland and Banded water snakes) that could be found here.  They resemble cottonmouths in size and color and are often confused with them.  They differ in that they have vertical dark stripes running across their jaws and have a round pupil.  Though nonvenomous, they will bite aggressively.  One member of the Nerodia group is the Gulf Coast Salt Marsh Snake (Nerodia clarkii clarkii).  This snake does like saltwater and is found in the brackish salt marshes on the island.  It is dark in color with four longitudinal stripes, two are yellow and two are a dull brown color.  It only reaches a length of 36” (3ft.), is nocturnal, and feeds on estuarine fish and invertebrates.

This banded water snake is often confused with the cottonmouth. This animal has the vertical stripes extending from the lower jaw, which is lacking in the cottonmouth.
Photo: University of Georgia

Other species that the guides mention, or I have seen, are the small Crowned Snake, Southern Hognose, Pine Snake, Pine Woods Snake, and the Rough Green Snake.  I will mention here species I have seen in either Gulf Breeze or Big Lagoon State Park that COULD be found on the island:  Eastern Coral Snake, Eastern Garter Snake, Pigmy Rattlesnake, Eastern Hognose, and the Corn Snake (also called the Red Rat Snake).  Only two of these (Eastern Coral and Pigmy) are venomous.

 

Last, but not least, is the Eastern Diamondback Rattlesnake (Crotolus adamateus).  This is the largest venomous snake in the United States, reaching 96” (8ft.).  It is a diurnal hunter consuming primarily small mammals, though large ones can take rabbits.  They prefer the dry areas of the island where cover is good.  Palmettos, Pine trees, and along the edge of wetlands are their favorite haunts.  Despite their preference for dry sandy environments, they – like all snakes – are good swimmers and large rattlesnakes have been seen swimming across Santa Rosa Sound and Big Lagoon.  They tend to rattle before you get too close and you should yield to this animal.  The have an impressive strike range, 33% of their body length, you should give these guys a wide berth.  I have come across several that never rattled, I just happen to see them.  Again, give them plenty of room when walking by.

Eastern diamondback rattlesnake swimming in intracoastal waterway near Ft. McRee in Pensacola.
Photo: Sue Saffron

It is understandable that people are nervous about snakes being in popular vacation spots, but honestly… they really do not like to be around people.  We are trouble for them and they know it.  Most encounters are in the more natural areas of the islands.  Staying on marked trails and open areas, where you can see them – and be sure to look down while walking, you should see them and avoid trouble.  For more questions on local snakes, contact me at the county extension office.

 

References

 

Ashton, R.E., P.S. Ashton. 1981. Handbook of Reptiles and Amphibians of Florida; Part One – Snakes. Windward Publishing, Miami FL. Pp.176.

 

Gibbons, W., M. Dorcas. 2005. Snakes of the Southeast. University of Georgia Press, Athens GA. Pp. 253.

The Rattlesnakes are Still Around

The Rattlesnakes are Still Around

This seems like a strange title… of course they are still around. However, it is referring to the number of encounters beach residents in the Pensacola Beach have had this year.  The first report was of a large individual coiled beneath a palm tree near a condominium unit by the gate of Ft. Pickens.  Park officials relocated that snake.  Soon after, another individual was found swimming in the surf of the Gulf of Mexico within the national seashore (honest… that is a strange place to find a rattlesnake).  A third was photographed snake crawling near the gate at Johnson’s Beach on Perdido Key, again within the national seashore.  I found a small individual coiled in the hollow space of a live oak tree at Naval Live Oaks in Gulf Breeze, again – within the seashore.  And last week I was driving through the Ft. Pickens area and saw another crossing the road near Battery Worth; it safely made it across the road.

Diamondback rattlesnake near condominium construction site Pensacola Beach.
Photo: Sawyer Asmar

Some would say, “Safely made it across the road? I would not worry about safely making it across the road” – but most of you know I am a fan of snakes and do not wish them ill will. Others feel similar but would rather they stay away from people.  I get that.  Some would have tried to run over the snake so that it was not a threat to others in the park.  I understand that thought process also but, as had been said before by many, snakes are beneficial to the ecosystem – benefitting us by controlling disease-carrying rodents, and rarely approaching people – it is usually the other way around.  Besides, this is a national park – you cannot run over snakes there.

 

So what’s up with all the recent encounters?

Is the island overrun with snakes?

 

This question came up last spring over on Perdido Key when a community was frequently encountering cottonmouths. It would obviously take a population assessment by a qualified herpetologist to determine the density of snakes per acre; but no such study is being conducted – nor are there plans for one anytime soon.  They tend to avoid people and, typically, become more visible when they are pushed from their hiding places.  They are also more visible during breeding season, which for the eastern diamondback rattlesnake is late summer and fall.

 

There is concern for safety when discussing the rattlesnake. So let’s learn a little more about this animal.  To know them better is to learn how to avoid problems with them.

Eastern diamondback rattlesnake crawling near Ft. Pickens Campground.
Photo: Shelley Johnson

The Eastern Diamondback Rattlesnake (Crotalus adamanteus) is the largest venomous snake in North America, reaching lengths of eight feet and 4-6 lbs. (though some have weighed as much as 15 lbs.).  They prefer high dry ground, such as the dune fields of barrier islands, feed on a variety of rodents, and have a particular fondness for rabbits.  Word is, if there are rabbits – there may be rattlesnakes.

 

When small, they have numerous predators including raptors, mammals, and even bullfrogs. To defend themselves, they lie beneath vegetation cover during the summer months and within burrows and stump holes in the winter.  Unlike the cottonmouth, rattlesnakes prefer to hunt during the daylight hours.

 

They breed in the fall just before the first cold temperatures and then settle into a burrow for the winter. They will have 12-24 young, delivered live, and the females will stay with the young until they shed their first skin, at which time the young are on their own.

 

They tend to avoid human contact and rarely venture into our territory unless (a) we have provided good habitat for their prey, (b) we have reduced their preferred habitat to a point they have no choice. Locally, all recent encounters (less one) have been within the National Seashore.  One encounter was in the dune fields near Big Sabine.  These are all natural habitats far from people – which is a good thing.

 

Rattlesnake venom is potent, and people should keep a respectful distance for this animal. My college professor said their venom is “expensive” and meant for killing prey.  What he meant by “expensive” was in terms of the energy and compounds to produce it.  That said, they would inject venom if their life depended on it.  One encounter I read about on a barrier island in Georgia involved a large eastern diamondback.  He said the head was close to 4 inches and the coiled body was large enough to cover a manhole.  He was not sure how long the snake was, but needless to say – it was a large snake.  He was actually a herpetologist who works with snakes and was searching for them.  He had a steel snake tong with him.  He used that to cover his leg and walked past the snake.  The snake never made an attempt to strike convinced it was camouflaged and did not need to.  He looked back after walking a few feet and the rattlesnake remained in the coiled position awaiting a rabbit.  Snakes that are annoyed will often rattle and lift into the S-shape strike position.  You should give an animal doing this plenty of room, their strike range is 2/3 their body length.

Eastern diamondback rattlesnake swimming in intracoastal waterway near Ft. McRee in Pensacola.
Photo: Sue Saffron

Despite our fears, these are fascinating and beneficial animals. There is a variety of reasons we may be seeing more on our barrier islands, but understanding them will help reduce negative encounters.

 

 

References

Gibbons, W. M. Dorcas. 2005. Snakes of the Southeast. University of Georgia Press. Athens GA. pp. 253.

 

Graham, S. 2018. American Snakes. John Hopkins University Press. Baltimore MD. pp. 293.

Roadkilled Reptiles: What a Shame

Roadkilled Reptiles: What a Shame

Roadkilled scarlet kingsnake in hand

This beautiful scarlet kingsnake was run over near the author’s home

Snakes are some of the coolest animals on the planet but I’ll admit to something right up front; when a snake surprises me, I still jump, often. Even if I seem composed on the outside, something inside me almost always jumps. It does not matter if it is a venomous species or not. In spite of my basic understanding of and great appreciation for reptiles, snakes connect with a primal instinct that shouts “lookout” at some subconscious level. This human character trait is most-often the undoing of many an innocent serpent, happily going about its business when, WHAM, lights out. When a snake dares touch the human subconscious, our first emotion is often shock or fear; then perhaps anger; and in the end, payback for the offense. Many a good snake has met a very bad end when it has surprised a person.

Shock and fear are powerful emotions and I can almost (not totally) understand the outcome described above when someone is honestly shocked by a snake’s unexpected appearance. Nevertheless, even my wife, during a shocking encounter with a 5-foot oak snake while collecting eggs in the chicken house, was able gather her wits and shoo the critter out of the coop with a stick, rather than kill it. She did have me go the next evening to get the eggs though.

The one thing I have no empathy for however is when folks go out of their way to kill a snake that is trying to cross one of our roadways. About 90% of the dead snakes I see on the road are so close to the edge of the pavement that they were easily avoidable. C’mon people, that should be a “snake-safe” zone. These animals are likely never to encounter a human as they go about their business, performing important ecological functions in their natural habitat. Their great misfortune was that they had to cross an asphalt corridor used by humans. How about providing the same courtesy that most folks do when they see a turtle on the highway.

I see my share of cottonmouths smashed on the road (and that’s a shame too in my book) but other flattened species I’ve encountered include mud snakes, rat snakes, garter snakes, ribbon snakes, water snakes, racers, scarlet kingsnakes, green snakes, and many more; all harmless creatures. Recently, I stopped to look at a nice 4-foot coachwhip; a beautiful specimen, except for the fact that it was dead.

I get a thrill in seeing a living snake and having the chance to marvel at its form, function and beauty. If you ever have the chance to look closely at a pygmy rattlesnake in the wild (hopefully not in your turkey blind) you will be blown-away by its magnificent beauty. Black, velvety blotches on a gray background, with a rusty stripe running down the middle of its back. Same thing for a large diamondback rattlesnake (from a respectable distance). These have been some of my favorite natural encounters in the woods of North Florida, where we are truly blessed with a diversity of amazing animals and yes, super-amazing snakes. We should always use common sense of course when roaming the woods and enjoying our wild encounters, i.e. don’t ever catch venomous snakes (not worth the thrill), keep your hands out of hidden places, and watch where you put your feet. Oh, and work on cultivating a “live and let live” attitude when it comes to our scaly friends on the highway. They will oblige likewise.

What’s Up With the Rattlesnakes?

What’s Up With the Rattlesnakes?

In the past week, three eastern diamondback rattlesnakes were encountered near the Ft. Pickens area on Pensacola Beach. The first was at a condominium unit near the park gate where construction work was occurring, the second was found swimming in the surf of the Gulf of Mexico within the national seashore, and the third was in the national seashore’s campground.  This is an animal we rarely encounter on our barrier islands – but that is the keyword… encounter… they are there, but tend to avoid us.

Eastern diamondback rattlesnake crawling near Ft. Pickens Campground.
Photo: Shelley Johnson

 

Report on rattlesnake in Gulf surf –

https://www.pnj.com/story/news/local/2018/09/26/snake-rescue-pensacola-beach-shocks-visitors/1430731002/

 

The eastern diamondback rattlesnakes (Crotalus adamanteus) is the largest venomous snake in the United States.  An average snake will reach six feet and five pounds, but they can reach eight feet and up to 15 pounds.  Because of their large bodies, they tend to move slow and do not often try to escape when approached by humans.  Rather, they lie still and quite hoping to be missed.  If they do feel you have come to close, they will give their signature rattle as a warning – though this does not always happen.  If they are considering the idea of striking – they will raise their head in the classic “S” formation.  Know that their strike range is 2/3 their body length – larger than many other native snakes – so a four foot snake could have a three foot strike range.  Give these snakes plenty of clearance.

 

Eastern diamondback rattlesnakes prefer dry sandy habitats, though they are also found in pine flatwoods (such as Naval Live Oaks north of highway 98 in Gulf Breeze). They are quite common in the upland sandhills of longleaf pine forests.  They spend the day in tree stump holes and gopher burrows and hunt small mammals and birds in the evenings.  They are particular fond of rabbits.  The dunes of our barrier islands are very similar to the sandhills of the pine forest further north.  They are actually good swimmers and saltwater is not a barrier – distance is.  They have been seen numerous times swimming from Gulf to Pensacola Beach or the opposite.  Again, they tend to avoid encounters with humans and are not often found on lawns etc.

 

Diamondbacks give birth to live young around August. The females will find a dark-cool location to den and give birth several young.  Anywhere from four to 32 offspring have been reported.  The female remains with the young for about 10 days until they have their first molt (skin shedding) and then she leaves them to their fate.

Diamondback rattlesnake near condominium construction site Pensacola Beach.
Photo: Sawyer Asmar

So what’s up with three encounters in a relatively small location within one week?

 

My first inclination is two possibilities – maybe a combination of the two.

  1. We have had a lot of rain this year – and then T.S. Gordon came through. Snakes like to be on high dry ground as much as anyone else and they tend to move closer to human habitats because they are built on higher ground.
  2. Breeding season for eastern diamondbacks is late summer early fall. This time of year, the males are on the move seeking interested females – so they are encountered more.

As far as finding one in the surf of the Gulf of Mexico. I am not sure.  I have never seen this and the newspaper account suggested it was not doing well when found.  Again, I have seen plenty swimming the Intracoastal but this is a first for the Gulf.  I would say it had wondered the wrong way.

 

They are actually fascinating animals and are not a threat unless you approach too close. Give them room and feel lucky if you get to see one.

 

 

References

 

Eastern Diamondback Rattlesnake. Natural History. Center for Biological Diversity.  https://www.biologicaldiversity.org/species/reptiles/eastern_diamondback_rattlesnake/natural_history.html.

 

Krysko, Kenneth L., and F. Wayne King. 2014. Online Guide to the Snakes of Florida. Florida Museum of Natural History, University of Florida, Gainesville, FL, USA. [Online: September 2014] Available at: http://www.flmnh.ufl.edu/herpetology.

https://www.floridamuseum.ufl.edu/herpetology/fl-snakes/list/crotalus-adamanteus.

It is March and Snakes are on the Move

It is March and Snakes are on the Move

Most people know that snakes are ectothermic and the environment is what regulates their body temperature. However, many do not know that they like to maintain their temperature close to 98 F like us.  To do this they must move to locations where they can either warm (like basking in the sun or lying on warm asphalt) or cool (like under rocks or logs).  Unlike us, their temperature can rise to above 100 F or down close to 30 F with few health problems.

Eastern Diamondback Rattlesnake swimming across the Intracoastal Waterway near Pensacola Beach.
Photo: Andy Barnes

When environmental temperatures become colder, their heart and breathing rates slow significantly. Their blood oxygen levels decrease, and they become very slow and sluggish – a condition we call torpor.  There are some advantages to this, such as not having to hunt for food for several weeks or months, but when the air temperatures begin to climb they become more active… Moreover, their hungry.

 

In the last two weeks, I have had numerous reports of snakes moving around in yards. There have been three records of diamondback rattlesnakes in the Pensacola Beach area alone.

 

Should I be concerned about doing outdoor activities?

 

No, not really – but you should be aware. As it warms, snakes will become more active early in the morning and late in the evening.  Pit vipers, like rattlesnakes and cottonmouths, actually prefer hunting at night.  However, when the temperatures are cool enough for mid-day movement, they will.  Food and reproduction (for some species) are on their mind this time of year.

 

Stay on the trails – snakes typically do not like to be in the open because of predators but they do have to bask to increase their body metabolism; so they may be along the edge. If I am hiking, I tend to look down along the trail when walking.  If I want to observe something in the trees, I stop.

 

These snake movements happen every year, and very people have problems, but with the recent increase in encounters it is could to be aware. I actually think snakes are pretty cool.  I enjoy seeing them, especially ones that are not viewed very often like coral snakes and rattlesnakes.  You should still go out and enjoy the Pensacola Bay area.  It is a great time of year to do it.