Potential Distribution of Colonizing Nine-Banded Armadillos at Their Northern Range Edge

Carly J Haywood,Clayton K Nielsen,F Agustín Jiménez

doi:10.3390/d13060266

Abstract

The nine-banded armadillo (Dasypus novemcinctus) has become a recent addition to the local fauna of Illinois as a response to habitat alteration and climate change. This range expansion has resulted in the presence of armadillos in areas not predicted by earlier models. Although these models have been revised, armadillos continue to move north and have reached areas of heavy agricultural use. We identified conditions that favor the presence of armadillos and potential corridors for dispersal. Identifying the distribution of the armadillo in Illinois is a vital step in anticipating their arrival in areas containing potentially sensitive wildlife populations and habitats. Armadillo locations (n = 37) collected during 2016–2020 were used to develop a map of the potential distribution of armadillos in southern Illinois. Environmental data layers included in the model were land cover type, distance to water, distance to forest edge, human modification, and climactic variables. Land cover type was the most important contributing variable to the model. Our results are consistent with the tenet that armadillo activity and dispersal corridors are centered around riparian areas, and that forested cover may provide corridors an agricultural mosaic.

Highlights

The nine-banded armadillo (Dasypus novemcinctus) has colonized much of the southernUnited States in less than 200 years [1]
Temperature and precipitation are thought to limit northern expansion to the 40th parallel north [3], armadillos have successfully adapted to a broader range of environmental conditions [4] and surpassed thresholds from previous models thought to be too cold to support the establishment of a new population, with records as far north as Nebraska and Indiana [3,5]
We modeled the influence of several environmental variables on potential distribution of armadillos in southern Illinois

Summary

Introduction

The nine-banded armadillo (Dasypus novemcinctus) has colonized much of the southern. United States in less than 200 years [1]. The current distribution of armadillos includes 15 states, and is expected to expand farther northeast [2,3] This range expansion has led to management concern about which factors facilitated their colonization, and what will limit establishment. The southern half of Illinois is surrounded by the Mississippi and the Ohio Rivers and sustains a robust population of armadillos This region of the state is covered with fragmented forest that connects the major river valleys with the corn belt. Biologists, health officials, and wildlife managers can use knowledge of habitat preferences and other environmental factors to forecast areas of potential armadillo colonization using species distribution models (SDM) [26,27,28]. We anticipated armadillo presence would increase with increased temperature of the wettest quarter and precipitation of the wettest quarter, as both temperature and precipitation limit colonization [2,3], but did not expect these climate variables to contribute to the model as much as annual precipitation, as annual precipitation has already been found to be of high importance in previous SDMs [2,3,25]

Study Area

Armadillo Presence

Environmental Variables

Findings

Potential Distribution