Ever tried to sex a dolphin? Me neither! But it seems like it is a difficult task for obvious reasons. A team of researchers decided to compare visible features (!) sizes, and scars! For those of you who get the wrong idea (admit it) I am talking about fins.
Via Nature News
"Rowe and Dawson found that male fins had significantly more scars than female fins, probably as a result of fighting. Male fins had a median of 15% scar tissue, whereas in females this was just 3.9%. Conversely, female fins tended to have a greater number of patchy skin lesions than male fins, with a median of 12.1% coverage compared with males' 6.8%.
The two then used a statistical analysis of scarring, number of fin nicks and fin size to correctly predict the sex of 93% of the 43 dolphins in the group. This laser-sighted technique could potentially be applied to other, less-studied populations of dolphin or even to other species, the scientists say."