It could be the wind or the birds will look for food and land on canes and the entire cane will snap.Bunnies probably not?

Could be either. Rabbits chop off canes at the bottom. Tender new canes, especially long vigorous ones, snap easily in all the wind we've been having.

~ nod ~

It's a mystery! At first, it breaks my heart to see the gorgeous canes all severed and limp next to the bush. But it doesn't seem to be harming the bush at all.

If i were really clever, i'd probably be able to discern tooth grooves if nibbling were the culprit. But i can't tell ... oh well! :)

Thanks guys ...

We have a lot of broken canes in our garden now too. It's the constant rain, wind, and the canes appear weak. New canes seem to break quite easily until they harden somewhat. It's very annoying to say the least to go out into the rose garden and find beautiful new canes, some with buds on them fallen on the ground. In our case we know it isn't bunnies, just the miserable weather we are experiencing this year.

~ nod ~

I'm convinced it's weather/wind related. Maybe it's a good thing to have the canes snap before the flowers burst - kind of a forced pruning?

My bushes were all planted last year, so i'm hoping this seemingly extended Spring has actually been good for the root systems. We'll see! :)

Thanks for the responses ...

I think it is the rain, too. My new canes seem very weak and when they get heavy from the rain, tend to fall over and break if they are not tied up. (I know how they feel, if we don't get some warm weather soon, I may snap myself!)