Okay, for a change of pace from today’s usual awful news, let’s talk about sex. We have three active osprey nests within two miles of our house. Yesterday, Wednesday, one pair was actively mating, copulating. There is no variety in the bird world; they all mate the same way. The male stands atop the female or hovers behind her. Both maneuver their tails, one to this side, one to that side, to allow cloacal contact. The cloaca is a bird’s all-purpose vent. Sperm is passed during very brief contact. This has been called the cloacal kiss.
The ospreys I watched, nesting on an athletic field light standard at Wayzata West Middle School, made contact or tried to make contact three times. I could not determine success. The birds knew, I suppose, the three attempts efforts to get it right or to insure success, or maybe to provide sufficient sperm, I don’t know. They would mate, the male would fly a wide circle, returning to the nest for another try. He took a brief rest on a nearby communications tower. She flew off the nest twice, briefly, circle and return.
One thing puzzling was the male’s delivery to the nest of a rather large dark object, like a small loaf of bread, that the male found in in the schoolyard and carried to the nest. I have no idea.
Osprey typically lay three eggs (1-4), which hatch in sequence. As was the case for the bald eagles on the DNR eagle cam, the last chick to hatch soften has a size and strength issue, unable to successfully compete with its older siblings for food. Even a day or two age difference matters. The eagles had three chicks, the obviously smaller bird eventually dying.
Osprey incubate their eggs for 37-38 days. Birds typically lay eggs in the morning, so the bird is not compromised by the weight of the egg during daytime activity.
The birds mated on April 23, possible egg laid today, April 24, plus 37 days incubation, giving a possible hatch date of May 31. Of course, I might have arrived for the third of three acts, today’s egg number three or four, in which case chick(s) arrive a few days earlier. Or, these were failed efforts, more attempts to be made. Or ……