Hopes are high that the pair may meet up and attempt to breed - something that hasn't happened since 1975 in Shetland.

In the past few days, a female bird has been spotted at the RSPB's Balranald Reserve, and a male just a few miles away at Grenitote. Small numbers of the birds show up from time to time in the Western Isles but have not bred as far as we know. In February last year two birds were spotted, but they were both males.

Martin Scott, Western Isles Officer with RSPB Scotland said: "This is great news, these birds are an absolutely spectacular sight and an inspiration to anyone that's lucky enough to see them. Just to have snowy owls around is special enough, but to have the prospect of them breeding is even better."

"We think they come over from North America, and in previous years have left rather than stay in the area - although of course if these two do pair up and raise a brood, they could be around for most of the summer."