I am sorry I have not found time to post much here lately. Please check the facebook page if you are on FB...there are more frequent posts there. I realize that many people are not on Facebook however, so I will share some of those posts here also.  I have been very busy doing the early season fieldwork. I have identified 72 Ospreys by their bands so far. Many nests are incubating now. The earliest hatching will probably occur in the third week of May. 

We are heading into one of the more ho hum phases of the Osprey nesting season...incubation. The books say they incubate for 35-43 days. Many years ago I concluded, on nests where I knew exactly when they laid eggs and when they hatched, that the incubation period in Minnesota is usually 39 days ( if the first eggs hatches). The researchers studying Ospreys in Pennsylvania came up with the same number. Most older pairs are on eggs now, tho some of the newer pairs are still courting and establishing territories. This is often the time when I discover new nests, so do keep your eyes open and let me know about any new nesting activity you might observe

Sometimes Ospreys that are not physiologically old enough to breed return and try to establish a territory. I was watching one of them yesterday...a 2 yr old female with an older male. I have never seen a 2 year old lay eggs. Typically these young females are unreceptive to copulation, which seemed to be the case at this nest. Often these females do act dependant upon the males for feeding, but this one was getting her own fish and when he tried to offer her a fish, she said "no thanks, I already have my own". So they were just engaging in parallel feeding...eating side by side in a tree, and she was going off on her own and he was bringing sticks to the nest. I did not see her working on the nest yesterday and I did not see any copulations. When he tried to mount her, she did not lift her tail. So we call them "housekeepers"...if they just hang out together in this territory, but do not reproduce. We will see what happens!

I have documented 2 year old males who attended nests where chicks did hatch, even tho it was previously believed that they were physiologically incapable of reproducing. I co authored a paper on the topic of 2 year old Ospreys and extra pair copulation that was published in the Journal of Raptor Research. I discovered that many ospreys were engaging in extra pair copulations, and that the females that were mated with these young males may have participated in copulations outside the pair bond. This may have explained the chicks that were being tended by these young males.

If you have any questions about Ospreys, please feel free to post it! I love to respond to your inquiries!