The energy regime in small Texas (U.S.A) caves differs significantly from many caves of the better studied eastern United States in that surfaceforaging cave crickets (Ceuthophilus spp.) are major contributors to these systems. The federally listed endangered cave invertebrates of central Texas are dependent on these crickets to transport energy from the surface to the cave environment. Using stable isotope analysis in combination with in-cave counts of animal life we examined cave invertebrate communities in nine caves chosen based on their low, medium, and high levels of human impact. Surface foraging cave crickets do not utilize the same food resources as the invasive red imported fire ant (Solenopsis invicata). The trophic position of the entire cave invertebrate community differed significantly between all three levels of human impact, for both δ13C and δ15N. Numbers of individuals of all cave taxa, including Ceuthophilus spp., are correlated with the level of human impact. As the percentage of impervious cover and percentage of impacted area increased, the total number of cave taxa decreased. This trend held true when either 11.2 or 90 acres around the cave entrance were considered in scoring the level of impact. Additionally, the total number of individuals of other taxa recorded from the caves was strongly correlated with the total number cave crickets. Maintaining land in a natural state within the foraging range of cave crickets (C. secretus and C. species B), and controlling the fire ant, S. invicta, are therefore important considerations in the management of Texas’ federally listed endangered cave invertebrates.
|Original language||English (US)|
|Title of host publication||19th International Conference on Subterranean Biology|
|State||Published - 2008|