A 1998 short, which I haven't seen.
Ice Age: Gone Nutty
A 2002 short, which I don't remember whether I saw or not. It was originally released on the Ice Age DVD.
Aunt Fanny's Tour of Booty
A 2005 short, which I don't remember whether I saw or not. It was originally released on the Robots DVD.
Ice Age: No Time For Nuts
A 2006 short, which I haven't seen. It was originally released on the "Ice Age: The Meltdown" DVD.
Ice Age: Surviving Sid (8:00)
Blue Sky Studios; Blue Sky Wiki; IMDb; Wikia; Wikipedia
This is the third short based on the Ice Age franchise. It came out in 2008, but I didn't see it until 2016. At this time, it's the only short by Blue Sky that I've seen, and that's only because it was included as a bonus feature on the Horton Hears a Who DVD. Anyway... Sid the sloth leads some young critters on a camping trip. They quickly discover that he's completely incompetent. I don't really know what to say, except that after a series of misadventures, Sid's final blunder leads to the accidental creation of the Grand Canyon. I guess it was reasonably amusing, considering it's just 8 minutes, but I expect the same quality level would have been really annoying if it were much longer than that. Still... I have no idea whether I'll ever see any other Blue Sky shorts, Ice Age related or otherwise, but it's not something I'd specifically avoid. (It's not something I'd specifically seek out, either, but whatevs.)
Ice Age: Cosmic Scrat-tastrophe
A 2015 short, which I haven't seen. It was originally released theatrically with "The Peanuts Movie."