It is not possible to determine whether half of the birds will fly away or not based on the given information.
The reason is that the total number of birds on the branch is only five, which is an odd number. If we divide the number of birds by half, we get a non-integer value of 2.5, which is not possible as we cannot have half a bird. Therefore, we cannot say for certain whether half of the birds will fly away or not based on the information given.
However, if we assume that the question is referring to a group of birds larger than five, and we divide the total number of birds by half, then it is possible that half of the birds will fly away, leaving the other half on the branch. But, we cannot say for certain based on the given information.