Spatio-temporal trends in armadillo diurnal activity and road-kills in central Florida

Armadillos (Dasypus novemcinctus) are one of the mammals most commonly found dead along Florida highways. Thus, they may serve as a mode to study which factors are affecting wildlife road-kills. Armadillo diurnal activity and road-kills were examined along a 168.9-km stretch of the Ronald Reagan Turnpike in Florida. We conducted 49 surveys during a 13-month period (3-5 surveys/month), with 143 road-kill incidents and 173 observations of active armadillos. Activity and road-kills were spatially and temporally correlated with several factors. Rate of armadillo road-kill was from interactions among temperature, vegetation coverage, and traffic volume. During winter (November-March), armadillos are more diurnal and generally less active, thus they are less likely to be killed by vehicles. Armadillo activity in these months was concentrated near habitat with dense woodlands. In summer, armadillos are predominantly nocturnal and apparently more active. Consequently, their road-kill rates nearly doubled and were highly correlated with traffic volume, but not with vegetation. Of all the traffic-volume data sets, mean nighttime traffic generated the only significant correlation with road-kills. Traffic did not affect armadillo diurnal activity. Our study demonstrated how the relative importance of the factors affecting road-kill changed temporally. Spatial analyses suggested that armadillos are more dispersed during summer.