Most of you are probably just settling into the spring semester, and you've only barely started to look at the data you collected in your most recent field season. May seems a long way off....
Reality: Federal and state permitting agencies are short-staffed. They simply do not have enough staff to process permit applications as quickly as they would like, or as quickly as you would like. If you wait until March or April, you could very well find that you don't get your permit/renewal in time for the start of your field season. Apply now and avoid the stress of worrying about getting your permit in time.
Remember - under Migratory Bird Treaty Act permits (including banding permits), you can continue your work under an expired permit so long as you have applied for renewal before the permit expired. That is NOT true of Endangered Species Act or CITES permits. It may or may not be true of your state permit - be sure to check.
USDA permits (needed for imports) do not allow the continuance of work after expiration, even if a renewal application is pending.
If you have any questions about what permits you need, how to get them, or any other questions about permits, please contact the Ornithological Council [ellen.paul *** verizon.net]