If you are female and are in trouble scream loud enough and a male will come and protect you. No need for us to mess up our nails when the trouble will be handled for us.
There is unfortunately an endless stream of data suggesting that this is not the case. Here is just the latest bit of counterevidence:
http://www.canada.com/victoriatimescolonist/news/story.html?id=efa6db04-d522-4c4e-ae69-7a3151c46912
My neice and her husband knew this young woman; they had gone to school together on Salt Spring.
You cannot rely on someone, male or female, to save you. The experienced predators pick their time and place, as well as their victim, carefully. You have to assume that in extremis, you'll be completely, totally on your ownjust you, your fighting skills and whatever weapons you carry or can improvise.
And you have to train for close quarters attacks, relentlessly, because attacks take place at close quarters. This young woman died of multiple stab wounds. A knife is a horrible weapon, but had she been better trained in awareness and self-defense, there's an excellent chance she still might be alive... Yes, females of every mammalian species at least will fight ferociously for their offspring, but they should fight just as ferociously for themselves. That's why I like that Dr. Ruthless clip so much. She illustrates the principle that to counter an attack, you must instantly redefine the situation as one where your attacker is the prey, and you are the predator, and you're going to hurt them, badly.