With the days getting warmer and longer where you live the predators will be out through out the day unless there is alot of hunting pressure on them, with the crusty snow it makes it easier for them to get around, hunt the valley bottoms or where ever you know the game are wintering, snowshoe hare, large game distress sounds and getting the ravens to congregate should bring in something.
Those yote move all day. I have shot them at all hours. If there is an hour I haven't shot one it's cause I didn't have a gun. hassel gave ya good advice. I have some additonal points. They will always come from down wind even when they have to travel 15 minutes to get there. They want to make sure of what you are. Scent sheild works great. I have to caution you. I make calls and people have called in bear with them and they crush tru everything too getting to ya. Just be ready! I have two sites www.predatorcalls4u.com and www.gamecalls4u.com some of my calls are on ebay. Type in "predator calls wood" and mine will come up. I make them out of mostly gunstock walnut. I also have some on www.etsy.com type in predator call and they will pop up. What else about calling? Um, start out with a sqeaker or really lite calling on your disressed rabbit call. They might be very close to you. Many time I have called them in with less than a minute past by. When you set up stay in the canyons and valleys getting to your set-up. STAY OFF THE RIDGE. They watch from there beds.
After you've called with your sqeaker or just quiet calling take a ten minute break. Then the first blast make the wake-up the town blast from your call. You wanna sound like you just got caught up and your legs stuck or you just got nailed by a fox or a hawk. The first sound from a distressed rabbit are the loudest. Don't be afraid to give it what youv'e got. Then work it down like they are getting tired. A few blasts and a few second break and start up again. I have heard a rabbit go for 12 minutes non stop. I have no idea why it stopped I could just hear it. I know it was a real one cause there was no one else allowed where I was. Only a rabbit and bobcat could have gotten there anyway. But 12 minutes thats a long time. I figure a bobcat was stting on it toying with it.
Listen you'll hear them all the time. Hell man they are the staple when it comes to food out there. Let me know if ya have more questions.
Alaskanhunter, here are a couple sites from youtube that are real cottontail/bush rabbits ya might find some snowshoes too. My point is they are making noise and you can get a understanding of what a real one sounds like. The two sites on Youtube, one a younger rabbit and the other is older and they sound very different. Therefore you can vary some too. Not to worrie.