Non-invasive techniques such as hair traps, camera traps, and scat samples can tell biologists a lot about habitat use and population size
Tools That Leave Wildlife Unbothered Widen Research Horizons. By Jim Robbins. New York Times
There has been a lot of discussion on this blog about radio collars and other invasive techniques used to get information about wildlife. After Macho B’s death this is a timely article.
I used to inject PIT tags into juvenile salmon and steelhead and the information gathered is valuable. The quandary with these methods comes from the fact that individuals will inevitably be killed and the wild nature of the animals can be affected.