Hairloss On Lucas' Ears

My kitty Lucas seems to be losing his ear fuzz a bit. It's not gone enough to see his ear skin, but it's getting very thin and you can begin to see his ear skin a little. It hasn't seem to be getting better, or worse in the past week or two. I was wondering if anyone knows what this might be?

Here's a picture of his worse ear [it's not as bad as it looks in the picture, but it's close]:

Have there been any changes, to food or in the environment? How old is the kitty? I think the hair on Zek's ears is looking thin, but the vet didn't comment at all when she examined them. It could be a genetic thing--Zek's a medium hair with some fluffy tufts of fur in a few spots, including his ears.

He's 9 or 10 months. Before he started losing his ear fuzz there was no changes in either. I did recently change his food though. Lucas is a Domestic Long Hair. Maybe it could be genetics. It doesn't seem to bother him, and he's not acting differently at all. I guess I'll see what my vet says when we go for his check up and shots.