Dad and son


I think that:
1 - pullet
2 - rooster
3 - pullet
4 - rooster
5 - pullet
6 - rooster
7 - rooster
8 - rooster
9 - pullet
10 - rooster
11 - pullet
12 - pullet
13 - rooster
14 - rooster
15 - rooster
4, 5 and 10 were born on May 6. Other were born on April 17.
I think they are all mix breed. Can you guess which breed it is between?