June 8 update

Here is a little update...I have read 83 bands and I know of 9 nests that have hatched as of Saturday, June 8. That will change daily now. As some of you may know, ospreys are asynchronous hatchers...meaning the chicks do not hatch at the same time, as ducks and geese do. Ospreys begin incubating after they lay their first egg and therefore they also hatch in sequence. This means that there can be as much as a weeks difference in the chicks ages. The difference can be very noticeable at the beginning, but by the time they fledge its hard to tell the difference. There is a stage, at about ten days to two weeks of age when they do engage in some sibling aggression. Many times i have observed the older chicks pecking at the younger ones. Siblicide is reported in the literature, tho I think it is uncommon. They usually establish the "pecking order", literally, and then that aggression seems to cease. If there is not enough food for all the chicks, some may die. I have seen runts that do not survive but I am not sure it is a direct result of sibling aggression. With all the new cams on nests, we may learn more about this aspect of sibling relationships. They usually produce 2-3 chicks, with 1 or 4 also seen. In my 20 years of studying ospreys I have seen broods of four chicks five times. Those occurred at two different nests. In all cases, all four chicks survived to fledging age!