This morning the male bird was distracted whilst incubating the three eggs and gave chase to an aerial predator. The female was away from the nest and so was unaware that the eggs where left undefended for a few minutes. During this time an opportunistic carrion crow landed on the nest and snatched one of the osprey eggs, after piercing its shell and eating some contents. The female osprey the appeared and settled back on the two remaining eggs , and when the crow returned for more, she was thankfully in position to defend them. Reviewing the nest camera footage we don’t believe the other eggs have been damaged – whilst another egg was picked up and dropped by the crow we believe only the one that was taken was pierced by its beak. Even a tiny hole or crack can introduce bacteria that will kill the chick inside, so we will continue to monitoring them carefully.
Whilst devastating, this is a case of bad luck and unfortunate timing and we must remember that this kind of predation is entirely natural- after all the crow is feeding its own mate and young just now too. We are confident that there was no human interference factor in this incident, though it highlights what can happen if ospreys are frightened off their nests for even short periods, by human disturbance.
We are just so lucky that the female returned in time and that we did not lose the whole clutch of eggs to this predator. The male bird was seen elsewhere on the loch chasing a crow moments later and we must not be too hard on him either- he is after all, just following his instinctive role which is to defend the nest and chase away intruders. A female osprey, by contrast, is usually canny enough to stay put on the eggs no matter what, and despite provocation by crows. It is perhaps a sign of his relative inexperience that he made this mistake. Our female with her long years of nesting experience is now clamped down very tightly on the eggs, and has refused to let the male take a turn incubating- who can blame her?