The RSPB administers a Corncrake Grant Scheme

The RSPB said while they were nowhere near the level of 30 years ago, the increase in calling males was promising.

The body said one of the corncrakes was at its Belfast Harbour nature reserve.

The RSPB's Anthony McGeehan said: "We are pleased the bird has decided the grounds we manage for waders like lapwing and redshank are ideal for it."

He added: "It shows that with the right management and some patience, nature does play her part. All she needed was a helping hand."

The RSPB said corncrakes were extinct as a breeding bird in Northern Ireland, but birds called from time to time in the spring.

They were made locally extinct primarily by the switch from hay to silage production - which disrupted the breeding cycle of the ground-nesting bird.

'Stay till July'

Mechanised harvesting meant they were often caught in the machines.

The organisation said it would be conducting a guided walk of the harbour reserve if the bird stayed.

"If the corncrake does find a mate, it will probably stay till July and call all the while," said Mr McGeehan.