Round table

It's dangerous to go without your birds; they get annoyed.

But what's the point of taking them if they'll just get crushed without any tactics? Besides, their morale in the first round is practically a death sentence, and at least this way, the birds will survive for the next week. Going into the first battle without any advantages (hiding spots, sufficient food supply, tactics, magic...) seems a bit reckless, the risk is huge.
But if you go in with the parameters and army that Rimpel described, then the risk is definitely justified.