Life History:
The newest member of our wildlife community on Seabrook Island is the armadillo. Armadillos are a non-native species in the United States. There are 20 species of armadillos found in Central and South America but only the nine-banded armadillo is found in the United States. This species originates from central America, first appearing in Texas in the 1880s. Since that time, they have continued a range expansion eastward and northward, arriving in parts of South Carolina as early as the 1980’s but not appearing on Seabrook until very recently. It is predicted that they will extend their range north at least as far as eastern Virginia.
Preferred habitat is dense, shaded cover with loamy or sandy soils near water – sounds like Seabrook Island! Their home range is generally less than ten acres. They routinely wade shallow water areas and are capable of swimming, so the fact that we are an island has not deterred their migration. Preferred foods are grubs, earthworms, ants, beetles and similar insects. Armadillos have one litter of young per year and always produce identical quadruplets derived from a single fertilized egg.
In tropical climates, armadillos are generally nocturnal but as they move north, they become diurnal during cooler months. As a result of their armored shell, they lack the hair/fur associated with most mammals and, therefore, have difficulty regulating their body temperature. At Seabrook, they will generally be seen from dusk to dawn but during our colder months we will likely frequently see them during daylight hours.
Potential Impacts to Seabrook:
Although the armadillo is a unique and interesting addition to our diverse wildlife community, their arrival here may have some impacts on residents. The primary damage done by armadillos relates to their digging. They dig holes for dens much like groundhogs, the difference being that a single armadillo may have up to 15 burrows. This may not be a significant problem if those dens occur in dense cover but often, armadillos will dig dens in lawns, under walkways and along foundations. We have seen a number of examples of this recently at Seabrook. More of a problem may be their foraging for food. Almost all their diet consists of worms, burrowing insects and insect larva. They have a great sense of smell and are capable of smelling a grub or earthworm up to 6 inches below ground. They can destroy lawns, landscape areas and golf courses by digging hundreds of holes up to 6 inches deep.
Golf courses across the south have suffered from armadillo damage. The extent of that damage depends on the pest management program for each course. On Seabrook Island, our courses are routinely treated to control those species of grubs and other burrowing insects that cause damage to our turf. By treating those pests, it is likely that most of the invertebrates that would attract armadillos would also be controlled. Since our greens and fairways are routinely treated, digging may be limited to mulched areas along the fairways.
For homeowners, it will be difficult to control armadillos digging in lawns and landscape areas. Most homes here have limited lawns but most do have mulched landscape plantings. These mulch areas are attractive to worms, grubs and other invertebrates that make up the bulk of an armadillo’s diet so it is these areas that will likely see the most impact. We have also been seeing homes where armadillos have buried under the house or paved areas.
There have been some reports of armadillo predation of ground nesting bird eggs. Most of these reports have not been proven but some researchers speculate that nests are sometimes destroyed by the random digging of armadillos. Stomach analysis has shown that diet is over 90% insect with no vertebrate remains. However, monitoring of quail nests have shown armadillos breaking and licking out the contents of eggs and a Georgia study has shown a 25% destruction of quail nests by armadillos. There appears to be no consensus on the impact of armadillos on ground nesting birds.
Population Control:
Like most newly introduced species, it is likely that the armadillo population will expand rapidly in our ideal habitat. In addition, they have no known predators in the United States since they are uniquely armored and none of our predators have evolved with them. Certainly, bobcats, alligators and birds of prey will take an occasional armadillo but they are not ideal prey and any population control due to predation will be negligible.
It has been reported that armadillos can be trapped using cage traps. Although that is true, its not like luring a raccoon or opossum into a cage trap with a can of sardines. Armadillos cannot be lured by bait and are uninterested in most food not found underground. Armadillos have very poor eyesight so the method of trapping them is to set a cage trap in an area where armadillos are actively feeding and use “wingwalls” made of boards radiating from the trap to guide a feeding armadillo into the waiting trap. It’s a hit or miss approach that is not very effective. A Georgia trapping study used both baited and un-baited traps as well as traps with wingwalls. Bait had no impact and their average number of trap night to capture one armadillo was 132! With that lack of success, it would be cost prohibitive to use this method for damage control. However, for those homeowners who have armadillos burrowing under their homes, there are several more efficient methods that animal control agents can use when they are dealing with an active burrow.
Another more adventurous method of removing an armadillo is to use a sturdy net and just catch them. They are slow moving and very easy to walk right up to but once netted they thrash wildly for several minutes so are difficult to handle. Armadillos are considered a nuisance species in South Carolina and, therefore, it is legal for residents to catch and dispose of problem animals. However, be aware that if you do catch one alive, it is not legal to relocate it and you must have it euthanized.
It is obvious that none of these capture methods are going to provide any widespread population control. So, it looks like we are stuck with co-existing with our newest wildlife species. Let’s enjoy our interactions with this unique invader from the south and we’ll work together to minimize any negative impacts.
-Submitted by Jaime Geiger, Chair of the Environmental Committee at SIPOA, written by Larry Mohn
(Image Credit: http://www.onlyinyourstate.com)