Cave Crickets Monitoring

Because food is scarce, cave crickets (Hadenoecus subterraneus) may consume whatever they find, including other cave crickets. Note the contrast in size between the juvenile cricket’s hind legs and the adult leg on which it is feeding.

NPS Photo

Cave crickets (Euhadenoecus and Hadenoecus sp.) are commonly found roosting just inside cave entrances throughout the southeastern United States. By feeding on the surface, cave crickets deposit nutrients in the form of guano, eggs, and carcasses between the surface and subsurface, and several cave communities are dependent upon these nutrients. Natural stressors that restrict cave crickets’ ability to forage on the surface, such as contingent climatic conditions like extremes in temperature and precipitation events, can alter the amount of nutrients they transfer to dependent subsurface communities. Stressors foreign to the cave ecosystem (for example, cave entrance configuration altered by management actions) can also affect the flow of organic matter into caves due to their effects on cave cricket foraging behavior and population structure.

Given the importance of cave crickets to subsurface ecosystems, the monitoring of their entrance populations over the long-term will provide park managers with an early warning of issues with cave ecosystem health, and contribute significantly toward managing and protecting the cave cricket populations. The network will focus long-term monitoring efforts on determining status and trends of cave cricket entrance population size, life stage, and sex ratio among 15 developed and undeveloped cave entrances at Mammoth Cave National Park during bienial visits. The network will also attempt to determine the potential effects of park management decisions on cave cricket populations within selected developed caves. Finally, the network will look for correlations between cave temperature, relative humidity and air flow trends, surface temperature, relative humidity and precipitation trends.

For more information contact Kurt Helf, Ecologist with the Cumberland Piedmont Network, at [phone] or via email.