Spawning phenology and habitat use in a Great Plains, USA, stream fish assemblage: an occupancy estimation approach

Abstract

Knowledge of basic life-history attributes, paired with unbiased estimates of species distribution, is critical for the effective conservation of sensitive fish species. We quantified the spawning phenology, habitat use, and detectability for larvae of an assemblage of threatened Great Plains, USA, stream fishes using new occupancy estimation methods. Spawning by six Great Plains fish species occurred from April through July, and was likely initiated by changes in water temperature and photoperiod. Habitat size and type were important factors influencing the occupancy of larvae in spawning habitats. Detectability of larvae differed among species and over time, and was influenced by habitat depth and fish size. Our models indicated that multiple samples from individual habitats within a season are needed to adequately detect and predict occupancy by stream fish larvae. Conservation efforts for imperiled Great Plains fish assemblages should focus on sustaining flows that maintain a sufficient density and size of habitats needed for successful spawning and recruitment. The occupancy estimation and modeling methods employed here will be useful in developing comprehensive, unbiased programs to monitor the reproductive success of Great Plains stream fishes.