One of the programs I do with Florida Sea Grant is Restoring a Healthy Estuary. There are four focus areas within this program: improving water quality, restoring habitat, managing invasive species, and enhancing wildlife. For those who know me, they know that enhancing wildlife is near and dear to me. My major in college was vertebrate zoology and I have been monitoring and teaching about vertebrates for 40 years.
I have found that the articles I write on this topic are my most popular, particularly snakes. And I get that. Whether you love them or hate them, snakes are interesting to read about. As we roll into 2024, I thought I would do a series of articles on vertebrates I encounter as I conduct hikes/surveys on our barrier islands. From a biogeographic view, barrier islands are interesting in understanding first, how some of the animals reached the island, and second, how they survive in a sandy/dry environment that is in many ways similar to deserts.
The white quartz sand beaches of the barrier island in the northern Gulf of Mexico.
Photo: Molly O’Connor
My first hike was just after the new year on the western end of Santa Rosa Island. Wintertime is cold and the ectothermic vertebrates (amphibians and reptiles) are hard to find, most going dormant this time of year. But, on sunny days when the wind is low, they can find places where they bask and stay warm. If you encounter them, they will most likely not move quickly (they are still cold) and this provides a better opportunity to view them, though their coloration is very cryptic with the environment and, with little motion, you may miss them. For the endothermic vertebrates (birds and mammals) this is their time.
On this warmer sunny January day, we spent several hours out. There was not much movement other than a variety of songbirds. Then we heard rustling in the woods under some live oak trees – it was an armadillo.
The common nine banded armadillo scurrying across the lawn.
Photo: Les Harrison
Many of us have encountered this interesting mammal. You may not have recognized it as mammal, but it is. As a lifelong resident of Pensacola, I know that prior to Hurricane Ivan there were fewer armadillos on Pensacola Beach. They were there but in low numbers. What was common at that time were striped skunks. Since Ivan I have not seen a skunk. I have asked park rangers at the Gulf Island National Seashore, and they have not seen them either. But the number of armadillos immediately increased. It seems the skunk left a niche open, and this animal took it. Some say the armadillo may have increased in population whether the skunks were there or not – that is just armadillos. So, who is this “new kid on the block” that has become so common on our islands?
Armadillos are native to central and south America. They are a smaller mammal in the Order Cingulata and related to anteaters and sloths. Mammals are divided into orders based on their dental formula (what type, and how many teeth they have). In this sense armadillos are unique. They have around 30 peg like teeth which they use to feed on insects, their larva, arachnids, snails, small vertebrates, and eggs – though reports of them raiding shorebird nests are rare. They do eat cockroaches, which many people appreciate. They acquire their food by digging into loose soil with their large claws. This is one reason they do so well on our beaches and why many homeowners dislike them – they can destroy a yard to find prey. Though they have poor eye site and hearing, which is noticeable when you encounter one, they have an excellent sense of smell.
Armadillos move relatively slowly seeking prey but when disturbed they can run quickly and swim well. They dig round burrows, which I have found many on Santa Rosa Island. Because they often share habitats with gopher tortoises, the burrows are often confused. Armadillo burrows differ in that they are completely round. With gopher tortoises the entrance is usually flat across the bottom and dome shaped across the top. Armadillos usually spend the daytime in these burrows, foraging at night with more activity near dawn and dusk (crepuscular).
One secret to their success is their reproductive rate. They breed in summer but hold off development of the embryo to allow a late winter birth. They only have one litter each year but is almost always four identical young of the same sex. This is because they develop from the same fertilized egg.
Diseases and parasites in armadillos are few compared to native mammals, rabies has not been documented. Leprosy has been documented in armadillos in Texas, Louisiana and Mississippi, but there have been no reports of infected ones in Florida.
The dispersal of armadillos from central to north America most likely occurred crossing the isthmus in Panama. But there are reports of the animals being released in eastern Florida beginning in the 1920s. It was noted that they were able to cross the Mississippi River in the 1920s when people began to build bridges for this new thing called the automobile. Eventually the Florida and Texas populations merged. They are dispersing north towards the Ohio Valley but are not fans of cold weather and this has been a barrier for further dispersal north. We will see what climate change will do to their range. They most likely reached our barrier islands by crossing bridges, though there are locations where the Intracoastal Waterway is narrow enough, and dredge spoil island frequent enough, they could have swam/island hoped their way over. Either way they are here.
Many dislike this creature and would like to see them gone. Some consider it an invasive species and needs to be managed. Others find them cool and enjoy seeing them. It was the only non-bird creature moving that day, despite the warmer weather, we will see what the next hike/survey will bring.
Florida has a love-hate relationship with this animal. Some find them cute and adorable, others find them a pest and a nuisance, either way there is no ignoring this guy. They are everywhere and yes – they can make a mess of your lawn and garden. So, for those who are not so in love with the creature – what can be done?
Let’s first meet the animal.
There are about 20 species of armadillo found in Central and South America but there is only one in the U.S., the Nine-Banded Armadillo (Dasypus novemcinctus). The Nine-Banded Armadillo is originally from South America and there were several different species of armadillos that made the trek from South to North America prior to the ice age. But after the ice age it seemed no armadillos were present in the U.S. After the ice age, the Nine-Banded Armadillo expanded north into Mexico, but it seems could not cross the Rio Grande. That is until Americans began to settle the area. Prior to American settlement, armadillos were hunted for food, and the land on both sides of the river was regularly burned. The American settlers ceased the burning and the Native Americans declined in numbers, so hunting pressure declined as well. Many armadillos were probably brought across intentionally, but others who managed to swim across, and armadillos can swim, now found suitable habitat with the decreased burning. They had arrived and began expanding both east and west across the southern U.S. However, the Mississippi River presented another barrier they could not deal with.
The common nine banded armadillo scurrying across the lawn.
Photo: Les Harrison
The introduction in Florida was a different story. Apparently in the 1920s and 30s they were released by humans. One release appeared to be an escape from a small zoo. Another was from a circus. There are reports of armadillos riding cattle cars on trains from the west and this allowed them to cross the Mississippi. In the 1920s bridges were built across the river for a new invention called the automobile. All of this led to the invasion and the animals are now here, they are also expanding north.
Armadillos like warm/wet climates. They prefer forested areas or grasslands and, again, can swim small rivers and creeks easily. It has been reported they can hold their breath up to six minutes and have been seen literally walking along creek bottoms.
They feed primarily on a variety of small invertebrates such as grubs, snails, beetles, and even cockroaches (many of you will like that). They like to feed in wet areas or loose sandy soils where digging is easier. Unfortunately, your lawn is a good place to hunt. They rarely, but do, feed on small reptiles and amphibians and eggs.
They breed in the summer but delay egg implantation so that birth is in the spring. They typically give birth to quadruplets. The armor of the young is not hard at first but hardens over time and does provide protection from large predators like panthers, bears, and alligators. They typically live 12-15 years, but some have reached the age of 20.
So… now you know the animal… for those who do not want them, what can be done?
Based on an article from UF IFAS Extension, not a lot. Typical methods of deterring wildlife have not worked. Poisons, smells, and even using firearms has not relieved the homeowner of the problem. One study looked at trapping and found that in general it is hard to get them to enter. In this study they caught one armadillo every 132 trap nights – low percentages. Another study looked at baits and found crickets and worms worked best, but the smell of other armadillos in the trap also lured them. One colleague mentioned the need for solid wood traps and he baits them with nothing but the shells of roadkill as had good success. He mentioned the designs of these wooden traps are online. You can get plans to build them, and you can also purchase pre-made ones. Once captured they can be relocated but the trapper should be aware that armadillos have many peg-like teeth and very sharp claws for digging. HANDLE WITH CARE. It is also known that armadillos can carry leprosy, though cases of leprosy being transmitted to humans are rare. None the less, handle with care.
For more information on this animal, contact your county extension office.
The common nine banded armadillo scurrying across the lawn. Photo: Les Harrison
The first light of morning can reveal random pockmarks in what had been the perfect lawn the previous evening. The culprit is not likely the neighborhood teenager with a reputation for inappropriate practical jokes.
The offender usually is the nine-banded armadillo, sometimes referred to as a Florida-speed-bump or Possum-on-the-half-shell. In addition to manicured landscapes, they also encroach in natural areas and destroy sensitive habitats.
Armadillos eat adult insects and larvae, but also quail and turtle eggs. They incessantly dig holes in their search for food, many times uprooting plants in their food search. Their foraging holes are approximately one to three inches deep and three to five inches wide.
Using insecticides in landscapes to decrease the armadillo food supply is not guaranteed, but may help reduce the digging. In cases where there is a large, and always ravenous, armadillo population this reduction of food may increase digging activity as they search more diligently for a smaller food supply.
Another consideration is all chemical treatments have to be reapplied on a permanent basis for long term control. Always read and follow label instructions for safe use of insecticides.
Armadillos rest in a deep burrow during the day and are usually active after dark. Burrows openings are approximately seven to eight inches in diameter, about the size of a one-gallon plastic jug, and up to 15 feet in length.
This exotic invasive may burrow under driveways, foundations and patios potentially causing structural damage. Additionally, their burrows in pastures pose a potential leg-injury hazard to large wildlife and livestock.
Several live-trapping techniques can be used to capture armadillos as they exit of their burrows. Because armadillos are nocturnal, trapping techniques designed to capture them as they emerge from their burrows should be applied late in the afternoon and checked several hours after darkness.
Fencing is another option to discourage the presence of armadillos. Relocating captured animals is illegal and not recommended because it only transfers the problem elsewhere and can spread this problem species.
Fossil records indicate the armadillo’s ancestors were as large as modern-day rhinos. One can only imagine what front yards would look like if they still existed.
