Automated telemetry and spot-mapping reveal similar space use in male and female Setophaga chrysoparia (Golden-cheeked Warbler)

Abstract

Studies that elucidate spatial and temporal patterns of space use are fundamental to avian ecology, and provide critical data to inform survey design, habitat management, and conservation planning. Advancements in tracking technologies have allowed researchers to locate and monitor individuals more reliably over time, thereby overcoming some inherent limitations of traditional methods (e.g., spot-mapping). We used an automated radio telemetry system (ARTS) to quantify home range size (i.e., the entire area traversed to obtain food and mates), spatial overlap (i.e., home range overlap between pairs, males, and females), and extraterritorial forays (i.e., movements outside the 95% kernel home range) for male and female Setophaga chrysoparia (Golden-cheeked Warbler). We also used spot-mapping to quantify territory size (i.e., the area defended by an individual), spatial overlap, and forays for male and female S. chrysoparia. Males and females had similar home range and territory sizes. Males conducted more forays than females; however, the number of forays per day, duration of each foray, and maximum distance of each foray were similar between the sexes. The territory sizes we estimated via spot-mapping were similar to previous studies and as expected, smaller than home ranges we estimated via automated telemetry. Automated telemetry improved our understanding of the spatial ecology of male and female S. chrysoparia. More broadly, our study demonstrated that ARTS designs can be used to investigate the spatiotemporal ecology of small (<30 g) birds, particularly females, which are typically more difficult to detect and monitor during the breeding season.