Wildlife enthusiasts were in cloud cuckoo land this week as an endangered bird’s distinctive call was heard on Hampstead Heath for the first time in decades.

Excitement swept the Heath’s bird-watching community as the rare sound of a male cuckoo rang out in Kenwood and then by the Mixed Bathing Pond on Tuesday.

Heath staff raced to the pond to listen out for the unique cry as word of its presence spread.

Ecologists believe it is the first time a cuckoo has been heard there for more than 40 years – and they say the wait for another one could be just as long.

Meg Game, senior ecologist at the Heath, said: “I have been living around here since 1981 and I have never heard one on the Heath. It was astonishing and perfect timing because I was with a group of bird watchers, who I lead on a walk every Tuesday.

“We just could not believe our ears, we were elated.”

Ms Game, 62, of Dartmouth Park Road, Dartmouth Park, said the bird was likely to be passing through on its travels, possibly on its way to Scotland, after spending the winter in Africa.

The Heath is an unlikely stopping off point because cuckoos usually favour large reed beds that are many acres in size.

The bird, which has not been caught on camera, is unlikely to stay for long, she added.

Tim Webb, from the Royal Society for the Protection of Birds (RSPB), which runs education projects on the Heath, encouraged people to “get over there” for potentially “the last chance to hear a cuckoo in London”.

The cuckoo is on the RSPB’s “red list” of globally threatened birds, following a huge decline in recent decades.

Mr Webb said changing agricultural patterns in Africa have contributed significantly to their plight.

Hunting is also a big problem, particularly in Malta where many are shot down as they fly over.

“They used to be very common, but you don’t hear them these days,” he said.

“It’s amazing that it stopped there, but it might just be passing through. This could be the last chance to hear a cuckoo in London, they’re really that rare.”