Ivy' is one of Princess' chicks and yes, its okay. It doesn't happen alot but when it does, either the pair aren't successful as a pair (the nest fails, they don't have many chicks) and the pair breaks apart to find a "better" match or they are successful and their chicks are successful. There have been a few very very successful brother-sister pairings in the US as well as parent-child so we aren't unique I'm afraid.
What we have found is that Nature knows what it is doing. If there is a problem, all species (with the possible exception of us whith our big brains and ability to ignore what is right in front of us when we want to) will work to ensure genes are successfully passed along to future generations. If there is a problem with the genes, they don't survive to get passed down either because there aren't any or very few chicks that survive to breeding age.
Before Ivy paired with Princess, he was paired with Jules for two years. For whatever reason, inexperience or incompatibility, they never managed to nest successfully. Last year Ivy takes over for Trey at the Radisson and he now has an experienced female to learn from and last year's nest was very successful with four healthy chicks and we hope to get news about them in the next couple of years. Jules on the other hand didn't need an experienced mate, she just needed another mate - and she paired with Beau and they too had a very successful nest last year.
If none of Princess' and Ivy's offspring survive to breed, Ivy will still have learned how to raise young from one of the best females we ever had. Princess isn't a young bird and one spring she won't return but hopefully Ivy will and then it will be his turn to be the experienced partner with a new mate. This is typically what happens at the Radisson and it has stood them in good stead.
Just as a final note - 50-80% of all peregrine chicks don't survive the first 12 months. Not all pairs produce young that survive to nest which is ultimately an indication of how success a bird is - Trey is successful because his daughter Alley has 2 chicks that are nesting - so success is multi-generational. And not all pairs are successful in this way.
Pop & Maud (3 yrs) - 3 chicks survived to have young of their own
Pop & Madame (4 yrs) - so far as we know, none survived to nest elsewhere
T-Rex & Madame (3 yrs) - 1 chick survived to nest successfully
Simba & Madame (2 yrs) - so far as we know, none survived to nest elsewhere
Trey & Madame (3 yrs) - so far as we know, none survived to nest elsewhere
Trey & Princess (6 yrs) - 4 possibly 5 chicks survived to nest successfully
Ivy & Princess (2 yrs) - all their chicks are too young so we have to wait
Hope that helps answer your question.
