Calculating spatial ranges of species and individuals is a crucial
problem throughout ecology. However, sample size biases can be strong,
and defining range boundaries can be difficult. These hurdles can be
overcome by calculating areas without calculating boundaries. The first
step is to algorithmically define a graph that connects the spatial
points where observations have been made. The routine generates a small
number of short edges that form a pattern resembling a mosaic. The edge
lengths are summed, squared, divided by the edge count, and multiplied
by a known constant to obtain a total area estimate for the shape. This
non-parametric mosaic area method can work with irregular outlines and
clumped point distributions. It is more accurate than convex hull,
kernel density, and hypervolume estimation according to simulation
analyses. Mosaic area calculations can be used in areas ranging all the
way from conservation biology to morphometrics.