A peregrine watch at Whitehead was abandoned after it was discovered the birds had left the immediate area.
The session scheduled for June 18 at Beach Road Nature Reserve was cancelled several days beforehand after experts found the main attractions were no longer there.
Ian Enlander, who leads this and other popular wildlife events, said: “Unfortunately the peregrines have deserted the nest site at Whitehead - this appears to be entirely natural as this is a well watched site and there has been nothing to suggest human interference.
“The female was still sitting through last week which is extremely late to still be on viable eggs (other pairs in the area have young nearly ready to fly if not flown from the nest) so likelihood is that the eggs were not fertile or got chilled earlier in the spring.”
Noting that female and male are now moving around a much wider area, he added “hopefully we will have better luck next year”.