[tundragriz]

Personally I think it would be very difficult without dogs, even then it is a toss-up. I don't think a human alone could pressure it enough to put it up a tree. For calling, the males especially, travel great distances only coming by an area maybe once a week. The odds of getting one in earshot would be hard and then of course you need to get it to respond. It does happen but almost always coincidental to calling something else. I think the odds of going out and saying this week I'm going to call in a lion would be very low. Personally I wouldn't want to shoot a female and certainly not unless I could verify she wasn't nursing. Lion breed year round, which is also why the males are always travelling so far, so you never know when the females have nursing kittens. When you have a female up a tree you are considering killing you need to be sure she isn't nursing, unless it is legal and you don't care. Here is a short clip from December a few years ago.

http://picasaweb.google.com/tundragriz/Utah2006Cougar#5397859430534373538

I think the best odds of calling would be to go to good lion country with migrating deer and elk. Walk a LOT where they are migrating and you will find kills. Find a kill that is still being fed on and set up there, never tried it but they usually aren't far from a fresh kill. They may visit it a couple times a day.