Academic journal article
By Hudgins, Rhonda; Norment, Christopher; Schlesinger, Matthew D.; Novak, Paul G.
The American Midland Naturalist , Vol. 165, No. 2
The goal of this study was to determine ecological, behavioral and environmental factors that would facilitate a management plan for the rare cobblestone tiger beetle (Cicindela marginipennis). We used a mark - recapture study to document dispersal distances of the cobblestone tiger beetle along the upper Genesee River in western New York and binomial logistic regression models to compare habitat characteristics measured during occupancy surveys. Cobblestone tiger beetles occupied cobble bars with approximately twice the interior area and difference between minimum and maximum elevation, and higher shrub cover, than unoccupied cobble bars. Beetles occasionally dispersed distances greater than the maximum distance between cobble bars in our study area. In order to preserve cobblestone tiger beetles and riparian habitats along the upper Genesee River, habitats should be managed to reduce impacts from recreational activities and sand/gravel mining.
Anthropogenic changes to natural waterways resulting in altered flow patterns and pollution can lead to loss of riverine invertebrates (Allan, 1995; SaintOurs, 2002; Bates et al, 2007). Lotie inhabitants face threats from land development and agricultural practices that include changes to water temperature, pesticide concentration, nutrient regimes, storm water discharge and flow due to impoundments and irrigation practices (Allan, 1995; SaintOurs, 2002; Bates et al, 2007). In New York State, loss of biodiversity and changes to riverine ecosystems are major management concerns (Pfankuch, 1975; Novak, 2006).
Tiger beetles (Cicindela spp.) are useful for tracking environmental change within riverine and riparian systems. They act as models for understanding, managing and conserving biodiversity and ecosystems (Rodriguez et al, 1998; Pearson, 2006), as they possess all or most of the seven criteria required for bioindicator species (Pearson and Cassola, 1992). Ideally, indicator species should (1) be in a well-known and stable taxon, with species easily and reliably defined; (2) have well-understood biology and life histories; (3) be easily monitored in the field by observers with differing skill levels; (4) occur across a wide geographical range in a broad number of habitats; (5) be narrow habitat specialists and sensitive to habitat changes; (6) have distributional patterns observed in other taxa; and (7) have potential economic importance that can be used to influence scientists and politicians to dedicate resources to relevant studies. Studies on speciation, extinction and ecology of tiger beetles have shown their usefulness as bioindicators in understanding complex habitats and environments (Pearson, 2006). One potential indicator species of natural habitat in New York State is the cobblestone tiger beetle (Cicindela marginipennis Dejean), a rare species adapted to natural river disturbances that maintain its required habitat, cobble bars.
Tiger beetles are variously considered a distinct family, Cicindelidae or a subfamily within the Carabidae, and nearly 2700 species have been described worldwide; most are similar in shape, proportion and behavior, and differ primarily in size and coloration (Pearson and Cassola, 2005). In the United States, 111 species of tiger beetles occur, 40% of which are habitat specialists (Pearson and Cassola, 1992). Eight species of tiger beetles, including the cobblestone tiger beetle, have been identified as "Species of Greatest Conservation Need" in New York State's Comprehensive Wildlife Conservation Strategy (New York State Department of Environmental Conservation, 2006) because they are scarce, occur only in small localized areas, with identified threats to their populations (Graves and Brzoska, 1991; Novak, 2006).
In New York State, the cobblestone tiger beetle occurs in at least two watersheds and is possibly extirpated from a third watershed (NatureServe, 2009; New York Natural Heritage Program, 2010). …