  WhyWhere is a new ecological niche modeling (ENM) algorithm for mapping and
explaining the distribution of species. The algorithm uses image processing
methods to efficiently sift through large amounts of data to find the few
variables that best predict species occurrence. The purpose of this paper is to
describe and justify the main parameterizations and to show preliminary success
at rapidly providing accurate, scalable, and simple ENMs. Preliminary results
for 6 species of plants and animals in different regions indicate a significant
(p<0.01) 14% increase in accuracy over the GARP algorithm using models with
few, typically two, variables. The increase is attributed to access to
additional data, particularly monthly vs. annual climate averages. WhyWhere is
also 6 times faster than GARP on large data sets. A data mining based approach
with transparent access to remote data archives is a new paradigm for ENM,
particularly suited to finding correlates in large databases of fine resolution
surfaces. Software for WhyWhere is freely available, both as a service and in a
desktop downloadable form from the web site http://biodi.sdsc.edu/ww_home.html.
