For January 6, 2011 and January 6, 2012 I compared the number of nests abandoned and the number of couples still incubating their eggs:
Year Incubating couples Abandoned nests Percentage abandoned
2011 17 11 39%
2012 28 9 24%
I would not be surprised if more nests are abandoned this season. I have two females whose mates have not yet returned to sit on the egg, and I have nests with 7 new couples this year, 2 of which have already been abandoned. It is not unusual for some new parents to abandon their first nest. There are 7 couples with PMRF eggs; I have never seen 100% of these hatch successfully. Still, it looks like we will have a larger number of chicks fledge than the 10 we had last year.