Variation in abundance and hatch date of Prairie Chub Machrybopsis australis in the upper Red River basin

Abstract

Understanding multi-scale population and life history relationships is key to informing management decisions. Abundance and life history relationships can provide insight on a species' status, population dynamics, recruitment requirements and guide fine scale conservation efforts. Life history strategies are often associated with a specialized habitat, connectivity and predictable flow patterns. These associations may vary across space and time. The Prairie Chub Machrybopsis australis is endemic to the upper Red River basin of Oklahoma and Texas. The Prairie Chub is of conservation interest due to uncertainty about its life history and status. Prairie Chub distributions are related to coarse scale flow metrics and are truncated by fragmentation. The goal of my thesis was to examine fine scale relationships to Prairie chub life history and abundance. For my first objective, I modeled the relationship between Prairie Chub hatch success and environmental variation. For my second objective, I estimated abundance and modelled the relationship between adult and juvenile Prairie Chub abundance and environmental variation. My findings help build upon known occurrence relationships and provide management agencies with a more complete picture of factors and potential threats influencing Prairie Chub populations and persistence.