I assigned arbitrary weights to your points; then, used Spatial Analyst
to contour the distribution. I chose to use "spline" to use "weight2"
and to use "tension" when asked various questions. Splines are smooth
curves formed from piecing together cubics in such a way that where cubics
of different equations come together, the slope of the tangent line from
the left and the slope of the tangent line from the right are the same.
A line pattern like the one above can be difficult to use as a backdrop--it's too busy for that. However, the same pattern can be displayed in a continuous range of color that is suitable for backdrop, as below.
There are packages that let you easily calculate "home ranges" (one from the USGS and the Alaska Biological Station)--here is one based on a "kernel"--it pulls out the two separated parts and surrounds the kernel with probability ellipses.
Or, one can just do the same sort of thing for the whole distribution of sites; here the largest ellipse is a 95% probability ellipse; the smallest is 5%.