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.

Getting Rid of Beach Vitex

Getting Rid of Beach Vitex

Yep,

We are still trying to remove this invasive plant from our area.  For those who are not familiar with it, beach vitex (Vitex rotundifolia) is a category I invasive plant in Florida.  It is current listed as “invasive, not recommended”.  This means you can still purchase it but recommend you do not.

Vitex growing at Gulf Islands National Seashore that has been removed. Photo credit: Rick O’Connor

Why is that?

Well, being an invasive species, it reproduces at a high rate, has few consumers, and causes an environmental issue wherever it grows.  It has the potential to cause economic issues as well.  Beach vitex is from Asia and was brought to the United States as an ornamental plant.  In upland landscapes, it does not seem to be a problem.  However, when first used in coastal dunes it began to show its ugly head.  Vitex begins as a low growing vine and becomes a shrub over time.  It produced a beautiful lavender blossom in spring but then produces millions of seeds in late summer and fall.  The seeds are spread by birds and are viable in seawater for several months.  Dispersed in this way, the plant spreads across coastal beaches of our barrier islands.

 

Once established it forms a taproot with above ground rhizomes extending as far as 20 feet.  It is allelopathic, meaning it produces chemical compounds that kill nearby plants and spreads to cover this new territory.  This includes the common sea oat.  Sea oats have a fibrous root system which are good at trapping sand and forming dunes.  These dunes can protect properties during storm surge.  Beach vitex, having a taproot system, are not as effective.  Though we are not aware of any beach vitex growing on the fore dune in the panhandle, if it does it could impact sea turtle nesting.  We are also not sure whether the local beach mice will eat these seeds.  Thus, displacing sea oats could impact beach mice.

Beach Vitex Blossom. Photo credit: Rick O’Connor

We currently know of one site in Ft. Pickens, two properties in Gulf Breeze, two in Navarre, four on Perdido Key and Perdido Bay, 24 within Naval Live Oaks in Gulf Breeze, and 38 on Pensacola Beach; 70 properties total in the Pensacola Bay area.  One of the properties in Gulf Breeze, and nine on Pensacola Beach (14%) have been removed or treated and have not returned.  One property in Gulf Breeze, one in Ft. Pickens, two on Perdido Key and Perdido Bay, 20 on Pensacola Beach, and 24 in Naval Live Oaks (68%) have been removed or treated but have returned; re-treatments are required and are being conducted.  And one property in Gulf Breeze, two in Navarre, two on Perdido Key or Perdido Bay, and nine on Pensacola Bay (20%) have not been removed or treated at all.  In each of these cases, the plants are on private property.  We hope that these property owners would consider removing the plant and replacing with native dune plants from this area.

 

Elsewhere in the panhandle we are aware of only two locations, one in Okaloosa County and one in Franklin.  We believe the property in Okaloosa has been treated and are not sure of the status in Franklin.  If is very possible that this plant is in the coastal areas of other counties in the panhandle.

 

Recently, volunteers from the Pensacola Beach Advocates and Americorp removed 315 m2 of beach vitex from public land on Pensacola Beach.  That now means all beach vitex on public lands in Escambia County have been removed or treated.  Research shows that repeated treatments may be required for up to five years to completely eradicate the plant from that property, but PBA and Americorp plan to assist Sea Grant with removing this plant from the area.

 

If you believe you have this plant and would like to learn how to manage it.  Contact Rick O’Connor at the Escambia County Extension Office.  (850) 475-5230 ext.111.

Vitex beginning to take over bike path on Pensacola Beach. Photo credit: Rick O’Connor

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.

The Marshes, they are a-changin’

The Marshes, they are a-changin’

Red mangrove growing among black needlerush in Perdido Key. Photo credit: Carrie Stevenson, UF IFAS Extension

Discovering something new is possibly the most exciting thing a field biologist can do. As students, budding biologists imagine coming across something no one else has ever noticed before, maybe even getting the opportunity to name a new bird, fish, or plant after themselves.

Well, here in Pensacola, we are discovering something that, while already named and common in other places, is extraordinarily rare for us. What we have found are red mangroves. Mangroves are small to medium-sized trees that grow in brackish coastal marshes. There are three common kinds of mangroves, black (Avicennia germinans), white (Laguncularia racemosa), and red (Rhizophora mangle).

Black mangroves are typically the northernmost dwelling species, as they can tolerate occasional freezes. They have maintained a large population in south Louisiana’s Chandeleur Islands for many years. White and red mangroves, however, typically thrive in climates that are warmer year-round—think of a latitude near Cedar Key and south. The unique prop roots of a red mangrove (often called a “walking tree”) jut out of the water, forming a thick mat of difficult-to-walk-through habitat for coastal fish, birds, and mammals. In tropical and semi-tropical locations, they form a highly productive ecosystem for estuarine fish and invertebrates, including sea urchins, oysters, mangrove and mud crabs, snapper, snook, and shrimp. 

Interestingly, botanists and ecologists have been observing an expansion in range for all mangroves in the past few years. A study published 3 years ago (Cavanaugh, 2014) documented mangroves moving north along a stretch of coastline near St. Augustine. There, the mangrove population doubled between 1984-2011. The working theory behind this expansion (observed worldwide) is not necessarily warming average temperatures, but fewer hard freezes in the winter. The handful of red mangroves we have identified in the Perdido Key area have been living among the needlerush and cordgrass-dominated salt marsh quite happily for at least a full year.

Key deer thrive in mangrove forests in south Florida. Photo credit: Carrie Stevenson, UF IFAS Extension

Two researchers from Dauphin Island Sea Lab are planning to expand a study published in 2014 to determine the extent of mangrove expansion in the northern Gulf Coast. After observing black mangroves growing on barrier islands in Mississippi and Alabama, we are working with them to start a citizen science initiative that may help locate more mangroves in the Florida panhandle.

So what does all of this mean? Are mangroves taking over our salt marshes? Where did they come from? Are they going to outcompete our salt marshes by shading them out, as they have elsewhere? Will this change the food web within the marshes? Will we start getting roseate spoonbills and frigate birds nesting in north Florida? Is this a fluke due to a single warm winter, and they will die off when we get a freeze below 25° F in January? These are the questions we, and our fellow ecologists, will be asking and researching. What we do know is that red mangrove propagules (seed pods) have been floating up to north Florida for many years, but never had the right conditions to take root and thrive. Mangroves are native, beneficial plants that stabilize and protect coastlines from storms and erosion and provide valuable food and habitat for wildlife. Only time will tell if they will become commonplace in our area.

If you are curious about mangroves or interested in volunteering as an observer for the upcoming study, please contact me at ctsteven@ufl.edu. We enjoy hearing from our readers.

Coastal Erosion–a problem with new solutions

Coastal Erosion–a problem with new solutions

Life on the Gulf Coast can be beautiful, but has its share of complications. Photo credit: Carrie Stevenson, UF IFAS Extension

Life on the coast has tremendous benefits; steady sea breezes, gorgeous beaches, plentiful fishing and paddling opportunities. Nevertheless, there are definite downsides to living along it, too. Besides storms like Hurricane Harvey making semi-regular appearances, our proximity to the water can make us more vulnerable to flooding and waterborne hazards ranging from bacteria to jellyfish. One year-round problem for those living directly on a shoreline is erosion. Causes for shoreline erosion are wide-ranging; heavy boat traffic, foot traffic, storms, lack of vegetation with anchoring roots, and sea level rise.

 

Many homeowners experiencing loss of property due to erosion unwittingly contribute to it by installing seawalls. When incoming waves hit the hard surface of the wall, energy reflects back and moves down the coast. Often, an adjacent homeowner will experience increased erosion and bank scouring after a neighboring property installs a seawall. This will often lead that neighbor to install a seawall themselves, transferring the problem further.

Erosion can damage root systems of shoreline trees and grasses. Photo credit: Carrie Stevenson, UF IFAS Extension

Currently, south Louisiana is experiencing significant coastal erosion and wetlands losses. The problem is compounded by several factors, including canals dredged by oil companies, which damage and break up large patches of the marsh. Subsidence, in which the land is literally sinking under the sea, is happening due to a reduced load of sediment coming down the Mississippi River. Sea level rise has contributed to erosion, and most recently, an invasive insect has caused large-scale death of over 100,000 acres of Roseau cane (Phragmites australis). Add the residual impacts from the oil spill, and you can understand the complexity of the situation.

 

Luckily, there are ways to address coastal erosion, on both the small and large scale. On Gulf and Atlantic beaches, numerous coastal communities have invested millions in beach renourishment, in which offshore sand is barged to the coast to lengthen and deepen beaches. This practice, while common, can be controversial because of the cost and risk of beaches washing out during storms and regular tides. However, as long as tourism is the #1 economic driver in the state, the return on investment seems to be worth it.

 

On quieter waters like bays and bayous, living shorelines have “taken root” as a popular method of restoring property and stabilizing shorelines. This involves planting marsh grasses along a sandy shore, often with oyster or rock breakwaters placed waterward to slow down wave energy, and allow newly planted grasses to take root.

 

Locally in Bayou Grande, a group of neighbors were experiencing shoreline erosion.  Over a span of 50 years, the property owners used a patchwork of legally installed seawalls, bulkheads, rip rap piles, private boat ramps, piers, mooring poles and just about anything else one can imagine, to reduce the problem. Over time, the seawalls and bulkheads failed, lowering the property value of the very property they were meant to protect and increasing noticeable physical damage to the adjacent properties.”

 

Project Greenshores is a large-scale living shoreline project in Pensacola. Photo credit: Carrie Stevenson, UF IFAS Extension

In 2011, a group of neighboring property owners along the bayou decided to take action. After considering many repair options, the neighbors decided to pursue a living shoreline based on aesthetics, long-term viability, installation cost, maintenance cost, storm damage mitigation and feasibility of installation. By 2017, the living shoreline was constructed.  Oyster shell piles were placed to slow down wave energy as it approached the transition zone from the long fetch across the bayou, while uplands damage was repaired and native marsh grasses and uplands plants were restored to slow down freshwater as it flowed towards the bayou.  Sand is now accruing as opposed to eroding along the shoreline.  Wading shorebirds are now a constant companion and live oysters are appearing along the entire 1,200-foot length.  Additionally the living shoreline solution provided access to resources, volunteer help, and property owner sweat equity opportunities that otherwise would have been unavailable.  An attribute that has surprisingly appeared – waterfront property owners are now able to keep their nicely manicured lawns down to within 30 feet of the water’s edge.  At that point, the landscape immediately switches back to native marsh plants, which creates a quite robust and attractive intersection. (Text and information courtesy Charles Lurton).

 

Successes like these all over the state have led the Florida Master Naturalist Program to offer a new special topics course on “Coastal Shoreline Restoration” which provides training in the restoration of living shorelines, oyster reefs, mangroves, and salt marsh, with focus on ecology, benefits, methods, and monitoring techniques.  Keep an eye out for this course being offered near you. If you are curious about living shorelines and want to know more, reach out to the Florida Department of Environmental Protection Ecosystem Restoration section for help and read through this  online document.

 

 

Sea Turtles of the Panhandle: 2016 Nesting Numbers and Notes

Sea Turtles of the Panhandle: 2016 Nesting Numbers and Notes

There are five species of sea turtles that nest from May through October on Florida beaches. The loggerhead, the green turtle and the leatherback all nest regularly in the Panhandle, with the loggerhead being the most frequent visitor.  Two other species, the hawksbill and Kemp’s Ridley nest infrequently.  All five species are listed as either threatened or endangered under the Endangered Species Act.

Due to their threatened and endangered status, the Fish and Wildlife Conservation Commission/Fish and Wildlife Research Institute monitors sea turtle nesting activity on an annual basis. They conduct surveys using a network of permit holders specially trained to collect this type of information.  Managers then use the results to identify important nesting sites, provide enhanced protection and minimize the impacts of human activities.

Statewide, approximately 215 beaches are surveyed annually, representing about 825 miles. From 2011 to 2015, an average of 106,625 sea turtle nests (all species combined) were recorded annually on these monitored beaches.  This is not a true reflection of all of the sea turtle nests each year in Florida, as it doesn’t cover every beach, but it gives a good indication of nesting trends and distribution of species.

If you want to see a sea turtle in the Florida Panhandle, please visit one of the state-permitted captive sea turtle facilities listed below, admission fees may be charged. Please call the number listed for more information.

  1. Gulf Specimen Marine Laboratory, 222 Clark Dr, Panacea, FL 32346 850-984-5297 Admission Fee
  2. Gulf World Marine Park, 15412 Front Beach Rd, Panama City, FL 32413 850-234-5271 Admission Fee
  3. Gulfarium Marine Adventure Park, 1010 Miracle Strip Parkway SE, Fort Walton Beach, FL 32548 850-243-9046 or 800-247-8575 Admission Fee
  4. Navarre Beach Sea Turtle Center, 8740 Gulf Blvd, Navarre, FL 32566 850-499-6774

To watch a female loggerhead turtle nest on the beach, please join a permitted public turtle watch. During sea turtle nesting season, The Emerald Coast CVB/Okaloosa County Tourist Development Council offers Nighttime Educational Beach Walks. The walks are part of an effort to protect the sea turtle populations along the Emerald Coast, increase ecotourism in the area and provide additional family-friendly activities. For more information or to sign up, please email ECTurtleWatch@gmail.com. An event page may also be found on the Emerald Coast CVB’s Facebook page: facebook.com/FloridasEmeraldCoast.