A bird of prey that kicked an arch-rival's eggs from a nest is now believed to have stood on and killed one of his own chicks.
Hopes are now pinned on the remaining two eggs
Osprey Henry destroyed the clutch at Loch Garten, near Aviemore, after returning to find his long-time mate EJ had mated with another male, VS.
However, he went on to father a fresh three eggs with EJ and the first chick hatched early on Thursday.
RSPB staff believe the young bird has died after Henry trampled on it.
It is thought that he may have killed his own offspring accidentally while trying to free himself from a piece of fishing line.
The incident, which took place during a rollercoaster breeding season at the reserve, has upset observers and workers.
Henry arrived from wintering in West Africa to find EJ had laid eggs with rival male VS.
Henry kicked the eggs from the nest, before fathering a fresh clutch which EJ has been incubating.
Hopes for the breeding season are now pinned on the remaining two eggs.
RSPB officials are hoping that they will hatch successfully over the weekend.