Summer habitat use and partitioning by two reintroduced rare madtom species

摘要

Habitat use by smoky madtoms (Noturus baileyi ) and yellowfin madtoms (Noturus flavipinnis ) was quantified in lower Abrams Creek within the Great Smoky Mountains National Park during the summers of 2007–2010. Variables were measured at both macrohabitat and microhabitat spatial scales within locations where each species was present. Reach-level macrohabitat data were analyzed using principal component analysis to identify variables associated with each species’ presence within a reach. Classification trees were developed to describe microhabitat use for each species and to compare differences in microhabitat use between species. Distributions of both species were similar in lower Abrams Creek with each becoming more abundant within downstream reaches. Smoky madtoms predominantly used riffle and run microhabitats with gravel and cobble basal substrates, while yellowfin madtoms used pool microhabitats away from riffles with low velocity and cobble-sized cover rocks. Neither species was ever encountered within the same microhabitat, suggesting summer habitats were partitioned. Models developed in this study can be used to identify potential reintroduction zones or to assist in conservation efforts.