Hi Vic and Sean
I agree with Baldwin Hedgehog about not handling too much, but not sure about the male’s ‘fifth leg’. You could mistake their tail for a fifth leg. However, you can sometimes tell on film if they get up on their legs and see a ‘blob’ or larger, as Baldwin Hedgehog says, in the tummy area. I usually find it is easier to see this from the side. If they scratch in front of a camera, it is also a bit of a giveaway.
The other way is, as the second link suggests, by observing their behaviour. You will need to watch for a while to be sure, because youngsters, in particular sometimes have some confusing behaviour, but in general it is the males which circle the females during courtship. You will probably need to wait until next year, now, to observe this behaviour as most of the hogs will be going off to hibernate, if they haven’t already.
I agree, you can’t tell them apart from their size. Some males can be quite small and some females quite big, although the older males here do tend to be a bit larger than the older females.
If you keep observing the hogs, you will be able to tell individuals apart by their natural markings. And I really recommend watching them in real time. Cameras are nice to have for back up, but nothing beats seeing the actual hogs. Things to look out for are facial markings, (similar to with horses) such as stars, blazes, dark ‘tear drop’ marks, etc. also their skirts (the hairy bit below the spines) and the band in between. These can be different colours, there can be different marks along the ‘skirt band’ (between skirt and spines), etc. I usually try to sketch the markings, as not only does it help you to observe more closely, but it is also a reminder. My current profile pic is a sort of template, which I use to start the sketch off, which you are welcome to use, if you wish, although you might be able to produce something better yourselves! I have written various things in more detail on the forum about natural identifying. If you are interested I will try to find one of them and send links.
Good luck to you and the hogs.