By Gene Carver, Wildlife Biologist
Armadillos were first noted in Alabama in the 1940s. Now, armadillos are found throughout the southern two thirds of our state. Human-armadillo conflicts usually arise from the animal’s habit of digging and rooting for insect larvae and grubs in nutrient rich soils--often in lawns, flower beds or gardens. Damage is usually localized in nature. The armadillo’s feeding habits in the wild have not previously been found to be detrimental to native populations of plants or animals. But in the past few years evidence has been mounting that armadillos are becoming a nest predator to Alabama’s ground nesting birds.
The nine-banded armadillo (Dasypus novemcinctus) is a distant relative of anteaters and sloths of South America. First seen in south Texas in the mid 1800s, they migrated north and east as far as the Mississippi River. Armadillos in Alabama probably came from Florida, where populations were started from accidental releases from zoos and animals unintentionally transported from Texas by truck and railcar.
Armadillos are mammals. They have hair (sparse belly hair only) and give birth to live young. The nine-banded name comes from the nine hard, horny bands between its armored shoulders and rump. They have large, strong claws on each foot and are very good at digging for food and digging burrows. The northern range of the armadillo is restricted by its lack of body hair insulation. An average temperature much below freezing limits their ability to survive. Hard, clay packed and rocky soils also limit their ability to dig for food and burrows. Armadillos prefer shrubby or tree-covered habitat where vegetation is dense.
Armadillos feed mainly on animal matter. Insects, ants, spiders, termites and other invertebrates make up the majority of their diet, particularly west of the Mississippi River. Quail and turkey eggs have been documented in armadillo stomach contents, but only in a few cases. Armadillos have been known to disturb and destroy quail and turkey nests in Alabama. Most data indicated this was incidental to the animal digging and rooting for food in the area of nests and not a result of direct predation of eggs.
The miniaturization of video surveillance equipment along with infrared lighting has allowed researchers to document nocturnal predation of quail nests. An armadillo was found to be one of the nest predators caught on video. The armadillo ate the eggs without digging in the nest. Turkey nest predation has been observed in Texas with all the eggs consumed by an armadillo. Nest predation by armadillos on threatened and endangered sea turtle nests has been documented in Florida. The armadillos dug up the underground nests and ate the eggs. These behaviors are believed to be recently learned feeding habits and not instinctive. Armadillos appear to be adapting to available food sources.
The destruction of quail and turkey nests by armadillos is now known to be fact. The potential as a limiting factor in these birds’ reproductive success, particularly in areas with high armadillo densities, is not known. Further research is needed. Elevation of the armadillo’s status from a nuisance critter to a predator of quail and turkey nests may not be as far fetched as first thought.