The Rise of Armadillos: Understanding Their Migration in Tennessee
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Chapter 1: The Journey of Armadillos
Armadillos can now frequently be spotted along the hiking trails of David Crockett State Park in Tennessee. This article, initially published in the Winter 2020–2021 edition of Tennessee Wildlife magazine under the title “Northern Migration,” has been slightly revised for clarity.
Dead armadillos have increasingly become a common sight on the roads of Tennessee. Unlike their South American relatives, the three-banded armadillo, the nine-banded armadillos cannot curl up into a ball when threatened. Instead, they tend to leap into the air out of fear, often resulting in fatal encounters with vehicles. While Tennesseans are now accustomed to seeing nine-banded armadillos, they were not always part of the landscape.
Section 1.1: The Arrival of Armadillos in Tennessee
Historically, armadillos were first spotted in Texas in 1854 and have been gradually migrating north and east for over a century. In the early twentieth century, some were accidentally released in Florida, which facilitated their spread.
Reports of armadillos in Tennessee began surfacing during the 1970s and 1980s. Today, it is believed that these creatures inhabit every county in the state; however, they were not present in certain regions until more recently. For instance, a study published in June 2012 by the Journal of the Tennessee Academy of Science stated that armadillos were absent from East Tennessee. The Tennessee Department of Transportation (TDOT) first noted deceased armadillos on highways in the Cookeville and Chattanooga areas in 2017. Biologist Roger Applegate from the Tennessee Wildlife Resources Agency expressed surprise at the swift spread of these animals, stating, “Fifteen years ago, I wouldn’t have imagined we’d be sitting here right now with armadillos virtually in every county in the state.”
Video Description: This video highlights the increasing sightings of armadillos across East Tennessee, showcasing their habitats and behaviors.
Section 1.2: Factors Behind the Migration
Scientists have proposed several theories regarding the migration of armadillos. One significant factor is climate change. Armadillos lack substantial fat reserves and do not hibernate, making them vulnerable to cold winters. Warmer temperatures have allowed them to survive farther north than before. Additionally, human activities, such as land clearing and irrigation, have rendered habitats more suitable for armadillos. As urban development has progressed, the decline of large predators may have also contributed to their success.
The construction of transportation networks may have facilitated their movement. Dr. Brian Flock from TWRA noted that the Mississippi River once posed a barrier to armadillos, but new bridges have lessened this impediment. Furthermore, humans may have transported armadillos to new areas, either intentionally or accidentally, as evidenced by reports of armadillos escaping from cattle cars in Mississippi during the 1950s.
Chapter 2: Armadillo Density Across Tennessee
The Tennessee Wildlife Resources Agency (TWRA) publishes annual reports on wildlife captures by county. The highest concentrations of captured armadillos are found in Williamson, Maury, Davidson, and Shelby counties. For example, Williamson County recorded 269 captured armadillos from July 2019 to June 2020, while Maury County had 195, Davidson County had 89, and Shelby County had 32. The numbers in Williamson and Davidson counties have notably increased since the first reports in July 2016.
Complete Animal Removal (CAR), a wildlife removal service in Middle Tennessee, receives more requests for armadillo removal in Williamson County than anywhere else. Isaiah Phillips, who schedules these jobs, mentions that calls about armadillos have surged, particularly in areas like College Grove, Nolensville, Franklin, and Brentwood, while reports of dead armadillos have also risen in Middle Tennessee.
Video Description: This video discusses how the migration of armadillos to the northern US is linked to climate change, featuring expert insights.
Section 2.1: Environmental Implications of Armadillo Presence
Armadillos are adept diggers, foraging for insects, invertebrates, and plants. While their digging may aid in decomposing forest debris and controlling pests, it is often perceived negatively.
Phillips notes that the signs of armadillo activity are distinct; rather than creating tunnels like moles or voles, armadillos leave behind scooped-out patches of dirt in search of food. Their digging can lead to substantial damage, especially in gardens. He states, “One armadillo can wreak havoc in a yard with multiple mulch beds.”
Fortunately, structural damage to homes is rare. Phillips estimates that only about 25% of his clients experience burrowing issues. Even when burrows are located near residences, they typically do not compromise structural integrity.
Section 2.2: Health Concerns and Armadillos
Beyond the physical impacts, there are health concerns regarding armadillos. Both armadillos and humans are known hosts of the bacteria that causes leprosy (Hansen’s Disease). However, it is essential to note that 95% of the human population is naturally resistant to this disease.
Dr. Ramanuj Lahiri, a leading researcher at the National Hansen’s Disease Program, emphasizes the low risk of transmission from armadillos. He advises people to avoid handling them but if necessary, to use gloves and wash hands thoroughly afterward. He also cautions those consuming armadillo meat to take similar precautions.
He reassures, “The chance [of infection] is small; every time you’re taking these precautions, you’re reducing it further.”
Section 2.3: Future Research and Considerations
Several questions remain unanswered regarding the ecological role of armadillos in Tennessee. For instance, do they disrupt the habitats of local salamander species? Are they competing with other wildlife for food resources?
As the armadillo population continues to rise, these questions may gain importance. Currently, humans represent the primary threat to armadillos, and there is limited attention or funding allocated for their study. Dr. Applegate notes, “We don’t have unlimited resources... there’s going to be very little incentive to try to deal with it.”
In conclusion, while the full extent of their impact remains uncertain, it is clear that armadillos are here to stay in Tennessee.