Question

which technology do environmental scientists use to track vulnerable populations of animals fitted with an electronic collar?

Answer 1

Scientists use radio technology in order to track endangered species. These include radio collars, tags and chips. These devices can then be tracked wither via satellites through GPS technology or by locating the radio waves emitted by these devices using receivers.
These devices have proven very helpful in tracking organisms and monitoring their populations. 

Answer 2

The scientists use the global positioning system (GPS)

APEX { GPS}