According to the research, the chances of a female managing to keep chicks this young fed and warm is statistically impossible. I've seen the nestsite location and it takes time to hunt, catch (remember falcons like all predators miss more than they catch) and prep a meal for transport and feeding. All of which is time taken away from the chicks who at this stage are defenseless and unable to thermoregulate. Average hunting success rate is about 23% (23 out of 100 hunts are successful) - for resident pairs on their breeding territories in the breeding season (i.e., when they are motivated to hunt successfully) it is a bit better than that (39%). But that still means that they miss half the time under ideal conditions - a female on her own trying to provide food for herself and her chicks as well as all her other duties and personal needs is fighting a battle she likely can't win. If the chicks were older, she would need to hunt for bigger appetites but they wouldn't need her at the nest so much.
Interestingly a raptor scientist in the US was just asking if anyone has any reports of lone parents being able to successfully raise chicks - so far I don't think he has received any affirmative reports.
I think I may argue with the statistics on this kind of situation. I have seen an instance of a female peregrine raising her chicks alone after her mate was injured during incubation.
I have also seen a case where a female, who did have a mate who did not contribute, incubated, brooded, hunted, fed and raised her four chicks on her own.
And I can think of a number of cases in which a peregrine (male or female) has continued to raise chicks after the loss of, or injury to, their mate.
Depends on what the criteria are, perhaps.
Oddly, the same question was posed on the Norwich site the other day via Twitter.
