Confronting incomplete detection to address questions about distribution and reproductive season for four imperiled stream fishes

Abstract

Geographical and ecological restrictions are the primary drivers of freshwater fish imperilment within the southeastern United States. To effectively manage existing populations and implement regulatory mechanisms of protection, information on the ecology and distributional patterns of imperiled taxa is needed. In this study, reproductive aspects including spawning behavior, microhabitat use and phenology were recorded for four imperiled percid taxa of the Upper Etowah watershed: the Etowah and Amicalola holiday darters (Etheostoma sp. cf. E. brevirostrum A and B), the Etowah darter (Etheostoma etowahae), and the bridled darter (Percina kusha). While accounting for incomplete detection, the occurrence of the spawning events was modeled according to visit characteristics to determine the duration of the spawning season. Additionally, patterns of spatial variation of the two holiday darter species were studied in an attempt to refine the known geographic range of these species and to identify factors influencing variations in occupancy and detection.