A number of these bulbs (many of them?) are poisonous, so there's been no noticeably predation on them here. For (larger) non-poisonous bulbs like crocuses and tulips, the problem here is voles (meadow mice), not chipmunks. I believe that chipmunks are solitary, unlike voles which can come in large numbers. The squirrels don't dig down deeply, here at least. Voles, however, mine out bulbs.
Another one of these poisonous little bulbs is Puschkinia libanotica, which is also quite attractive.
For me at least, a serious problem with at least several of these small poisonous bulbs is that they are also spreaders which seed all over the place and the spread can be impossible to limit (e.g. into the lawn, into the neighbour's garden, into an adjacent park). Personally I soon came to regret planting Chionodoxa and Puschkinia for this reason. On the other hand, I've been very happy to add more snowdrops to the garden every year.
