How do researchers estimate the number of black bear in a given area?

Question

I live in Washington state. We were amazed to read on below website that in 1998, it was estimated that there were 25,000 black bear in Washington state. This seems like a huge number. I'd love to hear how this number was come up with.

http://www.wdfw.wa.gov/wlm/game/cougbear.htm

I can imagine it involves radio collaring, looking for evidence of bear and knowledge about how large there home range is. Any other info about how this is done would be appriciated.

Answer 1

Thats actually a really good question. You are right, the main way is to do radiotelemetry or some form of mark-recapture. That is typically the most popular way to do it with most animals. I'm doing a mark recapture study on a snake I'm studying to determine how big one population is that I've found. Once all the data is collected, researchers typically use some sort of formula to get an estimate that is as accurate as possible, but realize in the end it is an estimate. Using the knowledge of their home range with available habitat can be factored in as well. Most wildlife organizations keep records of sightings as well made by wildlife biologists and those that are reported by citizens. Some studies even use DNA genotyping to estimate population sizes as well. Here are a few abstracts of some papers I've found that mention it. Hopefully this helps answer your question.

Answer 2

Well, you know they say researchers are smarter than the average bear

Answer 3

they set out traps and when the bears come it records thier visit