Cumberland Piedmont Network Cave Crickets Monitoring

Helf, Kurt

Natural stressors that affect foraging cave crickets’ ability to access primary productivity on the surface, such as contingent climatic conditions, can alter the amount of nutrient subsidies they provide dependent subsurface communities. Stressors foreign to the cave ecosystem, such as cave entrance configuration altered by management actions, can also alter nutrient subsidy flow into caves via their effects on cave cricket foraging behavior and population structure. Long-term monitoring of cave cricket entrance populations will provide park managers with an early warning system for cave ecosystem health and contribute significantly toward managing and protecting their populations. Objectives addressed by this protocol are: 1. To determine the status and trend of cave cricket entrance population size, life stage, and sex ratio among 15 developed and undeveloped cave entrances at Mammoth Cave National Park during biannual visits. 2. To determine effects of management decisions at Mammoth Cave National Park on cave cricket populations within selected developed caves. 3. To determine if a correlation exists between cave temperature, relative humidity and air flow trends, surface temperature, relative humidity and precipitation trends and trends in cave cricket entrance population size, life stage, sex ratio, and their spatial distribution within 15 developed and undeveloped cave entrances in Mammoth Cave National Park using biannual and continuous automated sampling. Our method exploits cave crickets’ tendency to roost in clusters, and consists of digital images of clusters intersected by randomly located strips perpendicular to a transect extending the length of the cave entrance. Analysis of the digital images yields count data which enable us to estimate total cave cricket entrance population size at a given cave entrance. Our design partitions cave cricket entrance population size into components of cluster size and numbers of clusters which will be used to assess temporal changes in population size and habitat use within and between developed and undeveloped cave entrances. Meteorological data will be collected from local subsurface and surface habitats. Opportunistic grab sampling uses handheld sensors to measure cave air temperature, relative humidity, and air flow at roosting clusters. Continuous sampling uses automated dataloggers to collect cave air temperature and relative humidity measurements in all 15 sampled cave entrances. Surface temperature, relative humidity, and precipitation are continuously collected by a local automated weather station. These meteorological data will be used to assess whether correlations exist between trends in surface and/or subsurface meteorological conditions and cave cricket entrance populations and habitat use. Long-term data contribute to the development of informative models of relationships between cave cricket entrance population dynamics and key environmental factors and management actions by resource managers.

Cumberland Piedmont Network Cave Crickets Monitoring

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