Worried that your period will attract unwanted attention from wild bears? Fear not! By referencing actual studies that look at actual bears' reactions to actual human menstrual blood, boingboing's Maggie-Koerth Baker has helped clear up some of the fact and fiction surrounding bears and lady business — and it's (mostly) good news!
Good news for ladies who like the woods-your period is (probably) not something that attracts (most) bears.
There are not a lot of studies addressing this particular topic, but a National Park Service paper published this year took a look at all of them and put the scattered pieces information together into a single puzzle. It's probably not a complete picture, but it's certainly better than hearsay and random, sexist stories you heard from your grandpa's drinking buddy. More importantly, even when there is a documented risk between menstrual blood and bears, that shouldn't be construed as a reason to keep women out of the wilderness. After all, bears are attracted to food, and we don't tell people they shouldn't eat while backpacking. Instead, we have practices that reduce risk. Same thing applies here.
Here's what we learn:
1) You can menstruate freely and without fear in the contiguous 48 United States. Grizzlies, and particularly black bears, don't seem to be interested in what's happening in your pants. Evaluating hundreds of grizzly attacks found no correlation between menstruation and risk of attack. In the case of black bears, this has actually been tested experimentally, with researchers leaving used tampons from various stages of menstruation out in the wilderness and watching how the bears respond. (Science!) The bears completely ignored the tampons.
Read the other two facts linking bears and lady business (including why this will be the second time I've gone out of my way to point out that the news is mostly good) over at boingboing.