Add stage of life category to bird counts (egg, chick, adult)

When entering bird counts, I’d like to specify whether the birds are adults or chicks. Eggs could also be added if someone thinks that is useful, but I’d prefer to have the nest monitoring functionality requested some time ago.
I was asked today how the caspian tern breeding season was at a particular location. I looked at my bird count which just said 120 and did not show the breakdown of how many of these were chicks vs adults.