The Winter 2012 issue of BATS, the BCI publication just out, has a very interesting article on an autonomous aircraft being developed to track radio-tagged bats on the wing. The work is being done by Nathan W Fuller (PhD candidate in biology at Boston University) and Kenneth D Sebesta, PhD (visiting scholar, Dept of Mechanical Engr, Boston University) with financial help from a BCI Student Research Scholarship. Allows bats to be tracked at nite in real time.
The fully autonomous airborne platform costs less than $500 in parts. I can foresee a system of this kind being used to track other elusive wildlife targets.