Use of a Camera Trap to Monitor Male Mating Territories of the Imperiled Callophrys irus (Lycaenidae)

Abstract

Camera trap technology is now commonly used to monitor rare and cryptic species of animals. In this study, we present the first use of a camera trap to monitor the imperiled frosted elfin (Callophrys irus Godart). We placed camera traps at two male mating territories (hereafter, ‘territory’) in north Florida 25 m apart to determine 1) the efficacy of camera traps for use in determining C. irus occupancy and 2) if camera traps can be used to monitor presence of individuals within territories. We marked 15 C. irus, seven females and eight males using a colored permanent marker to identify individuals in and around two territories. After 28.9 and 30.2 trap hours across six days, only one camera detected C. irus. This camera recorded 125 instances where C. irus continually remained within range of the camera trap. Of these, 31 observations included marked individuals, 41 events contained unmarked individuals, and 53 events contained C. irus that were unable to be verified as marked or not. Individuals remained within view of the camera for an average of 95.2 seconds (± 13.93 SE). Of 15 color-marked C. irus, two were observed via camera trap, two by human observers, and one by both camera and human observer. The mean Euclidean distance of resighted individuals was 110.25m (range: 16.4–207.08 m; number of resights ranged from 1–5). This evidence suggests that cameras are unlikely to capture all C. irus activity at a patch due to their limited field of view. Human observers therefore may be necessary to augment monitoring of host plant patches. However, the utility of camera traps demonstrated here offers a valuable tool in C. irus monitoring.