If you're going out herping, a decent pair of leather hiking boots is all you need. Unless you're going to be dropping logs and rocks on your toes (you should avoid moving that stuff much anyway as you're destroying vital habitat) you're never going to need steel toe boots while out herping. A good sturdy pair of leather hiking boots will give you plenty of protection, along with being lighter and more comfortable to hike around in all day.
Cheers, Cameron