The average gestation period for an alpaca is 345 days. This is only an average, the actual gestation can vary from 320 to 390 days or more and still result in a normal cria. Early births are more of a concern than late ones because most of the cria’s development takes place in the last 3 months of gestation. Our experience has been that births usually occur between 335 and 355 days after the last breeding.