Habitat prefrence modelling for the endangered Northeastern Beach Tiger Beele, Cicindela dorsalis dorsalis: Implications for rising sea level
The Chesapeake Bay serves as a case study for conditions that estuarine environments may experience in the future due to the rise in ocean levels as a function of global climate change. The Northeastern Beach Tiger Beetle (Cicindella dorsalis) is a federally threatened shore species that previously had a range from the coasts of Virginia to Massachusetts, but is currently only found along the Virginian portion of Chesapeake Bay and Martha’s Vineyard, Massachusetts. The primary threats to C. dorsalis are erosion and human traffic. The objective of this study is to determine the current habitat preferences and predict where future habitats due to climate change. We use a current distribution map (http://www.fws.gov/northeast/Endangered/tiger_beetle/pdf/Tigerbeetle2_92711.pdf) and measured the beach width at each known site in Google Earth using latitude and longitude coordinates then imported these into ArcMap. We used MAXENT modeling to predict the potential habitat range using environmental layers (precipitation, temperature, beach width), which contain known locations C. dorsalis. The objective of this study is to model and predict the potential habitat range of C. dorsalis; this information could be used to help relocate C. dorsaliswith poor habitat and strengthen metapopulations.
The initial results shows that the potential range of C. dorsalis to be extended into the Maryland portion of the Chesapeake Bay and along the eastern coasts of Virginia, Maryland, Delaware, and New Jersey. Some portions of the known locations have small beach width and it is suggested that these beetles either be relocated to a new beach or relocated to a University where they can be bred to further increase other populations. The MAXENT output shows the quality of locations for C. dorsalis. The relocation(s) for metapopulations must avoid beaches with high foot traffic because these attempts would be futile. Knowledge of the habitat preferences and the expanded potential range will help future conservation efforts by providing the sites most likely to be successful for translocation and restoration.