Miami is ground zero for invasive species in this state. But the Florida panhandle is no stranger to them. Where they are dealing with Burmese pythons, melaleuca, and who knows how many different species of lizards – we deal with Chinese tallow, Japanese climbing fern, and lionfish. The state spends hundreds of thousands of dollars each year battling and managing these non-native problem species. By definition, invasive species cause environmental and/or economic problems, and those problems will only get worse if we do not spend the money to manage them. Those who work in invasive science and resource management know that the most effective way to manage these species is to detect them early and respond rapidly.
Invasive species have made their way to the coastal waters and dunes of the barrier islands in the Florida panhandle. Beach vitex, Brown anoles, and Chinese tallow are found on most. Recently on Perdido Key near Pensacola, we found a new one – cogongrass.
Cogongrass (Imperata cylindrica) was accidentally introduced to the Gulf coast via crates of satsumas entering the port of Mobile in 1912. It began to spread from there and has covered much of the upland areas of the southeastern U.S. It has created large problems within pasture lands, where livestock will not graze on it, and in pine forest where it has decreased plant and animal biodiversity as well as made prescribed burning a problem – it burns hot, hot enough to actually kill the trees. The impacts and management of this plant in that part of the panhandle has been known for a long time. The Department of Agriculture lists it as one of the most invasive and noxious weeds in the country.
Two years ago cogongrass was discovered growing around a swimming pool area at a condo on Perdido Key. To be considered an invasive species you must (a) be non-native to the area – cogongrass is certainly non-native to our barrier islands, (b) have been introduced by humans (accidentally or intentionally) – strike two, we THINK it was introduced by mowers. This is a common method of spreading cogongrass, mowing an area where it exists, then moving those mowers to new locations without cleaning the equipment. We do not know this is how it got to the island, but the probability is high. Third, it has to be causing an environmental and/or economic problem. It certainly is north of the I-10, but it is not known what issue it may cause on our barrier islands. Could it negatively impact protected beach mice and nesting sea turtle habitat? Could alter the integrity of dunes to reduce their ability to hold sand and protect properties. Could it overtake dune plants lowering both plant and animal diversity thus altering the ecology of the barrier island itself? We do not know. What we do know is that if we want to eradicate it, we need to detect it early and respond rapidly.
According to EDDMapS.org – there are 75 records of cogongrass on the barrier islands, and coastal beaches of the Florida panhandle. This is most likely under reported. So, step one would be to conduct surveys along your islands and beaches. Florida Sea Grant and Escambia County of Marine Resources are doing just that. EDDMaps reports five records on Perdido Key and four at Ft. Pickens. It most likely there is more. A survey of the northeast area of Pensacola Beach (from Casino Beach east and north of Via De Luna Drive) has found two verified records and two unverified (they are on private property, and we cannot approach to verify). Surveys of both islands continue.
The best time to remove/treat cogongrass is in the fall. The key to controlling this plant is destroying the extensive rhizome system. In the upland regions, simple disking has been shown to be effective if you dig during the dry season, when the rhizomes can dry out, and if you disk deep enough to get all of the rhizomes. Though the rhizomes can be found as deep as four feet, most are within six inches and at least a six-inch disking is recommended. Depending on the property, this may not be an option on our barrier islands. But if you have a small patch in your yard, you might be able to dig much of it up.
Chemical treatments have had some success. Prometon (Pramitol), tebuthurion (Spike), and imazapyr have all had some success along roadsides and in ditches north of I-10. However, the strength of these chemicals will impede new growth, or plantings of new plants, for up to six months. There are plants that are protected on our islands and on Perdido Key any altering of beach mouse habitat is illegal. We certainly do not want to kill plants that are holding our dunes. If you feel chemical treatment may be needed for your property, contact the county extension office for advice.
Most recommend a mixture of burning, disking, and chemical treatment. But again, this is not realistic for barrier islands. Any mechanical removal should be conducted in the summer to remove thatch and all older and dead cogongrass. As new shoots emerge in late summer and early fall herbicides can then be used to kill the young plants. Studies and practice have found complete eradication is difficult. It is also recommended not to attempt any management while in seed (in spring). Tractors, mowers, etc. can collect the seeds and, when the mowers are moved to new locations, spread the problem. If all mowing/disking equipment can be cleaned after treatment – this is highly recommended.
Step one would be to determine if you have cogongrass on your property, then seek advice on how to best manage it. For more information on this species, contact your local extension office.
“I can’t do what? – because of a mouse? – it’s only a mouse.”
This was a comment made by many who lived on Perdido Key when a small beach mouse found only there was added to the endangered species list. It is a comment heard often when many species are listed. A major reason most species begin to decline and become endangered is loss of habitat. We enter and change the habitat to suit our needs. Much of this includes construction of buildings and altering landscapes to a more artificial setting and much of the local wildlife is lost. So is the case with this little mouse.
The Perdido Key beach mouse (Peromyscus polionotus trissyllepsis) is one of seven subspecies of beach mice found in Florida, five of those found in the Florida panhandle. Beach mice are a subspecies of the Old-Field mouse (Peromyscus polionotus). They are small, about 5 inches long, with tails that have hair (which are an additional 2 inches). Beach mice typically have a brown/gray color on top and a lighter white underbelly allowing them to blend into their environment very well. The difference between the subspecies is the extent of the coloration.
The subspecies status, and genetic isolation, is part of the reason these mice are listed. Members of a population who are genetically isolated from others can undergo a process called speciation where the genetic changes that occur in one isolated group cannot/do not flow through the gene pool of the other isolated group. Over time, the genetics, and morphology, of one isolated group becomes different enough that a new subspecies, or even species, develops. This is the case with the Perdido Key beach mouse. It is isolated on Perdido Key, a barrier island, and does not interbreed with their closest neighbors – the Alabama beach mouse (P.p. ammobates) and the Santa Rosa beach mouse (P.p. leucocephalus). Because of this, ALL of the Perdido Key beach mice in the world live on Perdido Key. Their population is small and vulnerable.
These mice are dune dwellers living in small burrows. They prefer the primary dunes (closest to the Gulf) which are dominated by the grasses whose seeds they like to feed on. They forage at night (nocturnal) feeding on the seeds of the sea oat (Uniola paniculate), panic grass (Panicum amarum), and blue stem (Schizachrium maritimum) usually in the secondary dunes. Highly vegetated swales (low wet areas between the primary and secondary dunes) are used to move between these habitats, and they are also found in the tertiary dunes (on the backside of the island where trees can be found) where their burrows are more protected from storm surge during hurricanes. During periods when seeds are not available, beach mice will turn to small invertebrates to support their diet. Their foraging range averages around 50,000 ft2.
Breeding takes place in the winter, though can occur anytime of year if enough food is available. They are monogamous (males pairing with only one female for life) with the females giving birth after 23 days to four pups. New members of the family can move up to half a mile in search of a foraging range for themselves. It is understood that with limited available habitat on an isolated island, the carry capacity of the beach mouse would be low. Owls and snakes are some of the predators they face, but the beach mice have evolved to deal with few predator issues.
The increase of humans onto the barrier islands has negatively impacted them. The leveling of dunes for houses, condos, swimming pools, and shopping centers has significantly reduced suitable habitat for them as well as reduced the seed food source. Introduced feral and free roaming domestic cats have also been a large problem. Bridges connecting these islands to the mainland have allowed foxes and coyotes to reach, and increase pressure on, them. With these increased pressures, and small populations, these mice are now listed under the Endangered Species Act.
Conservation measures have included, predator control, building and landscaping restrictions, translocation (moving mice from large populations to those that are smaller), and reintroduction (releasing mice into areas where they once existed but no longer do). There has been success with the Choctawhatchee beach mouse in the Grayton Beach area, as well as the Perdido Key beach mouse in Gulf Islands National Seashore. Things that beach residents can do to help beach mice populations include keeping your pets inside at night, plant native grasses in your landscape, reduce night lighting, do not walk over dunes – use the cross walks.
Things seem to be improving for beach mice, but the development pressure is still there. Hopefully we will have these creatures as part of our panhandle barrier island communities for many years to come.
Beach Mouse Fun Facts. Gulf Islands National Seashore. U.S. Department of Interior.
For better or worse, tropical storms are exciting. Besides the energy and tension around the mystery of where a storm will make landfall, the combination of powerful waves coming ashore, intense wind gusts, and driving rain really heighten all the senses. Most long-time Floridians don’t flinch too much at a Category 1 or 2 hurricane. But once we cross the threshold of a Category 3+, things change. If you have lived through a storm like Frederic, Ivan, or Michael, you know the damage and heartache these stronger storms can bring. Even Category 2 storms like Hurricane Sally just three years ago had serious lasting impacts, particularly affecting the under-construction Pensacola Bay Bridge.
Post-covid, with the economy (sort of) back in full swing, we are averaging just over 1,200 people a day moving to Florida. From July 2021-July 2022, nearly half a million people arrived, compared to 185,000 in the same timeframe the previous year. While some of these new residents may come from storm-prone locales, many have zero experience with hurricane season on the Gulf. If you are among those new to hurricanes, or know neighbors who could benefit from information, please share these tips with them.
Tip 1: Have the right insurance. The vast majority of insurance companies will not issue new policies when there’s a storm in the Gulf. Officially, hurricane season begins June 1. So, if you don’t have enough coverage for your investments, you should go RIGHT NOW and look into it, before the storm season really heats up in late summer. In addition, different types of policies cover different types of damage. Homeowners’ insurance (fire, theft, etc.) in Florida requires a separate windstorm policy, which includes damage from hurricanes and high winds (always confirm by reading your policy). And these are both separate from flood insurance. Performing certain types of windstorm mitigation, such as wind-rated garages, strong roof to wall connections, and obtaining shutters, can significantly reduce your overall costs for windstorm insurance.
Flood insurance is available through the National Flood Insurance Program (NFIP) and can be reasonably priced for people living outside of a flood zone. Those within designated flood zones will be required to purchase it, and rates vary widely depending on location and any prior flood impacts.
As for which policy pays for storm impacts, it will become a game of “whodunit” afterwards, with adjustors making determinations of your damage based on the specific characteristics of each storm. These may include the direction of the incoming storm, the windspeed, amount of rain, and where any water damage actually originates from.
Tip 2. Create a disaster kit. Whether you are hunkering down and riding out the storm or getting out of the fray, it’s important to have a disaster kit with certain necessities. I always recommend a waterproof tote bin, to protect important documents from rain or floodwater. Items for a kit include medication, flashlights and batteries, shelf-stable food that can be eaten without heating or refrigeration, gallons of water, pet food, cash (since ATMs won’t work), portable phone chargers, a list of emergency contacts, and insurance paperwork. Comprehensive disaster kit lists can be found at floridadisaster.org. Another benefit of keeping these materials in a portable container is that if you do have to leave your home in a hurry, everything is in one place.
Tip 3. Come up with an evacuation plan. Talk with your immediate and distant family about your plans for a storm. If you plan to evacuate, look at the direction of an incoming storm and find a place to stay that is out of the immediate cone of impact. Sometimes this means moving east or west along the coast; other times it’s best to head inland. It’s important to let others know you’re leaving, in case there are serious impacts to your home from flooding or wind and rescuers are in the neighborhood.
During the spring and early summer beach vitex is not in seed and this is a good time to remove this invasive plant from your property. This time of year, the leaves have their unique blueish-green coloration, allowing them to stand out from other plants on your lawn, and soon will also have their lavender flowers. It will appear as a series of vines running across the surface of the sand extending from a central taproot.
To remove it you begin at the end of the vine away from this central point and slowly, carefully pull it from the sand, cutting it into two-foot sections to make it easier to bag. The vine may have smaller secondary roots extending from it that you have to carefully remove as well. If you are lucky, and the plant is relatively small, you may be able to pull all of the vines and the taproot with no tools. But if the plant is more established, the texture of the vine may become more woody and you will need to use loppers (or clippers) to remove it. The same is the case with the taproot, you may have to use a shovel to get it completely out. If you cannot remove all of the taproot, you may have to spray the remaining section with an herbicide. All cuttings should be double bagged before disposing to reduce the chance of spreading by fragmentation.
Beach vitex (Vitex rotundifolia) was brought to the United States from Asia in the 1950s as an ornamental plant. In the 1980s the states of North and South Carolina used in dune restoration where it exposed its invasiveness. The plant quickly spread, killing off native vegetation, such as sea oats, and forming dense monocultures on the dune. As the plant matures it becomes more of a woody shrub and much more difficult to remove. The shrub blocks sunlight not allowing the germination of other plants and the vines can extended onto the beach impacting sea turtle nesting. We are not sure at this time how it may impact the beach mice found in Florida.
We are not sure when it was first introduced to Pensacola Beach, but it was first found in 2014. Since then, Florida Sea Grant has been able to identify 2 sites in Gulf Breeze, 1 at Ft. Pickens, 24 in Naval Live Oaks, and 57 sites on Pensacola Beach where the plant exists (or did exist). One Pensacola Beach, 54 of the 57 sites are east of Casino Beach. 22 of the 57 sites are on public lands, and with permission from the Santa Rosa Island Authority, Florida Sea Grant uses local volunteers to manage those. However, 35 are on private property and we hope those homeowners will take the initiative to remove the plant to help stop its spread.
If you have questions on identification or methods of management, contact Rick O’Connor at the Escambia County Extension Office – email@example.com, (850-475-5230 ext.1111).
No one species has altered the land, sea, and sky – as well as decreased the overall biodiversity of the planet in such as short time as has Homo sapien. Since we have arrived on this planet we have slowly dispersed across all continents, oceans, and even the polar regions. In our wake we have changed the landscape. Altering forests and changing waterways. We have built communities and cities and, in recent years, increased the amount of waste we produce to impact the land, water, and even change the climate. Our planet has encountered major changes in climate and habitats before – but not at the rate it is currently happening, and many are not able to adapt fast enough. Wildlife over much of the planet has declined due to our activities – and barrier islands are not an exception.
Humans first arrived in the Florida panhandle a little over 10,000 years ago. Most of them built communities along our riverways and deltas. As with much of coastal wildlife, barrier islands were difficult places to inhabit. There is little freshwater, selected game to hunt (though an abundance of seafood – which they did seek), intense heat in the summer and cold in the winter, and tropical storms – where there were few places to hide. It appears humans did visit the islands but did not settle there. The early European colonists tried, but unsuccessfully – they had to moved inland.
In the Pensacola Bay area, the first settlements that were successful were fortifications placed there by the U.S. Army to protect the communities where people lived. These were brick fortifications that held up well against the storms, all built with large cisterns to collect freshwater for the troops stationed there. Soldiers accessed them using ferries.
In the early 20th century locals from Pensacola built a casino at what is now Pensacola Beach. There were casinos, boxing, and food vendors for those who made the day trip by ferry to visit the location.
Much of this early human activity had little impact on the island wildlife. Humans were concentrated in specific locations and did not / could not venture very far from them. But when automobiles became more commonplace with people, bridges soon followed, and things did begin to change. More cars meant more people, and the need for roads. These roads bisected the dune system and altered how they naturally progressed with wind and waves. Not only did dune dynamics change but dunes began to disappear with the new homes and hotels that were built.
Homes, cars, and roads made life for several island creatures tough. Most of the shorebirds using the islands as nesting areas lay their nests on the sand. The white/speckled eggs blend in well with the white sand and the warm sand helped incubate them. There were fewer predators on these beaches and so, protection of the chicks was achieved more by driving off any potential threat by “dive bombing” them. This did not work with humans, nor their cars. The roads became hazards for them, and small chicks were often hit by cars. Today some species are threatened and have been given federal protection.
In recent years beaches houses have become true homes, with lawns and gardens. This alters the natural landscape even more. Along with the altering of the dune systems, this impacted many dune creatures like the beach mice. The species on Perdido Key is now considered endangered, and also has federal protection.
Additional housing, development, and roads led to additional needs in lighting in the evening. Many barrier island creatures need “dark skies,” but notably are the nesting sea turtles. In recent years 50-60% of sea turtle nests on our islands have had adults and hatchlings “disorient” towards the artificial lighting instead of the moon/star light that reflects off of the Gulf. This, along with other human related impacts like structures left in the sand at night, have caused a decline in these turtles and they too are now federal protected.
You could not mention impacts by the human presence without mentioning solid waste – marine debris. Modern humans produce a wide variety of plastic products which we bring to the beach, and some of it ends up in the environment. Sea turtles, shore birds, and even manatees have been found either entangled in it or having ingested it. Much of this marine debris is problematic for the wildlife there.
Recently there has been an increased issue of pet cats that are allowed to roam the island at night. These pets (some strays) are known for the impact they can have on small wildlife like birds.
We were lucky in Escambia County during the 1970s to have the National Park purchase about 50% of the island as a National Seashore. This has provided a space for the island creatures and a great nature/cultural tourism destination.
No one moves to the beach with the intent of harming wildlife, but our sense of changing things when we arrive – which we have been doing for some time – does impact them. The answer to this problem is to learn how to live, and develop, with the wildlife on the islands. The islands play a crucial role in protecting the mainland from storms and providing habitat for several unique species. Many of these species are beneficial to our lives by playing an ecological role in maintaining the island. It can be done.
I hope you have learned something new in this nine-part series on barrier island wildlife. If you have, please let me know by emailing firstname.lastname@example.org. I hope you get a chance to explore our islands and maybe see some of these neat creatures.
The definition of an invasive species used by the University of Florida IFAS has three parts.
It is not native to the area.
Was brought to the area by humans; either intentionally or accidentally.
Is causing an environmental or economic problem, or somehow lower the community’s quality of life.
Florida is famous for its invasive species problems. Actually, every state in the country is battling this issue. In 2005 the estimated economic cost of invasive species in the United States was $137 billion annually. Looking at the Invasive Species Curve (below) you can see the most effective method of managing is to prevent them from coming in the first place. Easier said than done. International travel and commerce by plane and boat enters Florida every day, who knows what these are bringing with them. There is the legal trade, illegal trade, and the accidental hitchhiker. Though there are efforts in each state trying to prevent invasive species from entering, they do enter. Once they have arrived, resource managers move into what we call Early Detection Rapid Response (EDRR) in hopes of eradicating the species but at the very least containing them. It is a constant battle.
Though separated from the mainland, our barrier islands are not immune to this threat. Humans travel to and from our islands all year round; we live on many of them. With us comes non-native species we both intentionally and accidentally bring. Some of these become invasive and can threated the wildlife of our islands. The state is divided into 15 Cooperative Invasive Species Management Areas (CISMAs). The western panhandle is under the Six Rivers CISMA, the eastern panhandle is under the Apalachicola Regional Steward Alliance (ARSA). Both CISMAs have developed a EDRR list for their area. As a member of the Six Rivers CISMA, I helped developed ours and below are the species considered the biggest threats to our island wildlife.
Beach vitex (Vitex rotundifolia)
Beach vitex is native to the Pacific coast of Asia and was intentionally brought to the United States as an ornamental/landscape plant. It does well in open sunny areas, dry soils, along the coast – perfect for barrier islands. In the 1980s it was used for dune restoration in the Carolinas and that is when its invasive nature was first seen. Like all invasive species, there are few predators and disease, and so reproductive success is high. The species multiples and spreads rapidly, basically uncontrolled. Beach vitex is allelopathic, meaning that it creates an environment that can kill nearby plants and thus take over that area; sea oats are one species this occurs with. Its impact on wildlife could include the loss of required habitat and food source. It appears to have already impacted sea turtle nesting in the Carolina’s, and that threat exist here as well. It could also impact the ecology of the listed beach mouse.
I was first made aware of the presence of this plant in the Pensacola area in 2013. It was discovered on the shoreline of a private property on the Gulf Breeze peninsula in Santa Rosa County. It was suspected to have come from nearby Santa Rosa Island. A survey of the Pensacola Beach area found 22 sites where the plant existed. One was quite large, covering about 70% of the property. The others were small individual plants. Some were part of a homeowner’s landscape; others were on public land. At the time, beach vitex was not listed as an invasive species in Florida. Today it is and has also been declared a state noxious weed. A database search indicates there are currently 118 records in the state of Florida found in six counties. Four of those counties are in the Florida panhandle and include Escambia, Santa Rosa, Okaloosa, and Franklin. More in-depth surveys of the coastal areas, and islands, of the remaining counties in the panhandle may find more records of the plant. There are active projects in the Escambia/Santa Rosa area to manage it.
Cogongrass (Imperata cylindrica)
Cogongrass is native to Central and South America. It was brought to the United States accidentally through the Port of Mobile. It quickly spread across the landscape covering much of south Alabama, northwest Florida, and Mississippi. It now can be found in most of Alabama, a large portion of Mississippi, much of Louisiana and Georgia, some of the Carolina’s, Tennessee, and Virginia, and in every county of Florida. It is not only listed as an invasive species in these states, but also as one of the nation’s worst noxious weeds. It quickly covers pastureland. Being serrated and having silica with the grass blades it is not palatable to livestock, you can lose good pastureland when this invades. In natural areas and private timberland, it quickly covers the understory where it burns too hot during prescribed burning efforts and creates a situation where the valuable management method cannot be used. It is not a good plant to have on your land.
In 2020 we were made aware the plant was growing on Perdido Key in Escambia County. We are not sure how it got there but most likely from landscaping equipment that was not cleaned after working an inland area where the plant was present – this is a common method of dispersing the plant. Currently there are 456 records along the coast of the Florida panhandle. 404 of these are on coastal beaches and 52 are on our barrier islands. 44 of the island records are on Santa Rosa/Okaloosa Island, 4 at St. Andrew’s State Park, 1 on Cape Sand Blas, and 1 on St. Vincent Island.
What impact this plant will have on barrier island wildlife is not fully understood. But we know that it has not been beneficial within inland habitats and the potential of having a negative impact is there. Locally we will begin to survey for exact locations on the islands in Escambia County in 2023 and begin a management plan for those, as well as education outreach to reduce potential sources.
Giant Salvinia (Salvinia molesta)
This is a new invasive species to our area and, until recently, was only found within our state in the panhandle. There are now 19 records found in 7 counties across the state; 10 of the 19 records are in Escambia County. This is a freshwater species that prefers quiet backwaters with high levels of nutrients. In our county the plant is concentrated in the upper arms of Bayou Chico. Though an estuary, Bayou Chico has relatively lower salinities than most of our other bayous – the plant is doing well there. The Florida Fish and Wildlife Conservation Commission (FWC) began management of this area a few years ago, but it is still there and seems to have spread to a nearby retention pond. The best guess as to method of dispersal were beavers seen moving back and forth between the water bodies. We plan to conduct surveys of other nearby retention ponds in 2023.
Though relatively new to Florida, it has had a large impact on the freshwater systems of Texas and Louisiana. I witnessed firsthand that impact at a lake near Shreveport LA where I was camping. This plant is a small one that floats on the surface of the water. It resembles duckweed but the leaves are larger. It had completely covered the surface of the lake and was kept out of the swimming area by using booms. There was no way to fish in the lake and moving through with a paddle craft would have been difficult. It is similar to water hyacinth covered waters. Though the swimming area was clear, the bottom had become “mucky”, and no one was swimming. All water recreation had stopped. The thick canopy covering the surface of the lake blocks sunlight so no submerged grasses can grow, the dead plant material decomposes and draws down the dissolved oxygen levels which could create fish kills.
Knowing this, FWC has a team focused on eradicating this plant from our state before such situations occur here. Though it will not reach our barrier islands by floating there (because of its dislike of salt water) if it DID reach any of the retention ponds near the homes, hotels, and condos, via landscaping equipment used on inland ponds, or some other method, it could be a real problem. And, as we have seen in Bayou Chico, wildlife could move it to the natural freshwater ponds on the island. We will begin surveys of all ponds on Perdido Key and Santa Rosa Island in 2023.
The Brown Anole (Anolis sageri)
This small lizard from Cuba (also known as the Cuban anole) has been in Florida for some time. It most likely reached our shores accidentally by hitchhiking on a boat. With south Florida’s tropical climate, the lizard did quite well and began to disperse north.
I first encountered the creature on campus in Gainesville. Along west side of Ben Hill Griffin Stadium (The Swamp) are trees that are enclosed in wooden boxes – a sort “raised bed” look. When I looked in one of them there were numerous brown lizards scattering everywhere. I checked the next tree and found the same. I found the same in each of the tree boxes along that road. I then began to see them at the rest stops on I-10 between Pensacola and Gainesville. You would step out of the car and as you walked you would see numerous small brown lizards scattering everywhere. The same ones as in Gainesville – the brown anole. I then received a call from a resident on Innerarity Point Road near Perdido Key. She wanted to know what type of lizard she was now seeing in her yard. They were small, brown, had white spots (diamond-like patterns) on their backs and were EVERYWHERE. I asked for a photo, and eventually made a site visit, they were the brown anole. I then began to receive calls from other residents near Perdido Key, then from Gulf Breeze, then from the East Hill area of Pensacola. All the same. The brown anole had made it to Pensacola. Interestingly, when I was speaking to a garden club about invasive species, and was discussing this one, residents from the north end of the county had no idea what I was talking about. They had never seen them. They apparently were invading near the coast. Between 2018-2021 I was conducting a cottonmouth survey on Perdido Key for a Homeowners Association who was encountering a lot of them. At first the brown anoles were not there. Then, during the second year of surveying, I began to see them. The brown anole had reached the barrier island.
It is believed that the mode of dispersal is the same as how they reached Florida in the first place – hitchhiking. Most likely on landscape plants that were grown in south Florida, transported up here, and delivered to you. It is not quite clear how they may impact barrier island wildlife. We know where they show up the native green anole (Anolis carolinensis) begins to decline. Some studies show that the green anoles move higher up in the trees and shrubs where needed resources are limited, and the population will most likely not survive. I have watched green and brown anoles battle it out on my front porch (yes – I have brown anoles in my yard also). I have seen green anoles win these battles – but they seem to have lost the war. I seldom find them anymore. What changes may happen to wildlife on the barrier islands we will learn with time. Though I have not personally seen one on Santa Rosa Island, I am sure they are there – and probably on your barrier island also.
Cuban Treefrog (Osteopilus septentrionalis)
As with the brown anole, it is believed the Cuban treefrog reached our state hitchhiking on a boat. They too have been in the state for quite some time. But records in the Florida panhandle were non-existent. It was believed that the winters here too cold for them. But that appears to be changing.
I have had occasional calls about this frog over the last few years. In each case it was a single individual, hanging on their windows and glass doors, shortly after the homeowner had purchased new plants for landscaping. As with the brown anole, we believe this is a common method for spreading them. But as we mentioned, there was not much concern because our cold winters would keep this invasion at bay. Then there was a report of several Cuban treefrogs at a location on Tyndall AFB in Panama City. They appeared to be breeding and also appeared that they had overwintered. Dr. Steve Johnson (of the University of Florida) later confirmed this to be the first recorded breeding group in the panhandle. And the “love had begun to spread”. More accounts were being reported in the western panhandle. One community in Santa Rosa County found over 100 over the course of a year. Again, we think they are spreading with landscaping plants, or hitchhiking by other methods.
The issue with the animal is similar to that of the brown anole. It is much larger than our native treefrogs and likes to devour them. They are large enough to eat small native lizards and snakes as well. They produce a mild toxin in their skin that can irritate your eyes, nose, and even trigger asthmatic attacks. They have been found in toilets and are known to even plug the plumbing. They have also been found in electrical power boxes and have caused power outages. Overall, they are pain to deal with.
There are currently 28 records in the Florida panhandle. Though some have been found along the coast of our estuaries, there have been no reports on our barrier islands. Maybe we can educate the public on the hitchhiking issue and possibly keep them off the islands. We will be initiating a citizen science effort to monitor their locations on Pensacola Beach and Perdido Key beginning in 2023.
Invasive species, by definition, are a problem for barrier island wildlife. But another problem they are facing is the increase in humans. That will be the topic in part 9.