A pair of snowy owls arrived last year, but they were male
A male and female snowy owl seen on North Uist the Western Isles could become the UK's first breeding pair in 30 years, RSPB Scotland said.
Last year two birds were spotted, but they were both males.
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.
The previous pair to breed in the UK was on Shetland in 1975, the wild bird conservation charity said.
The birds of prey may have arrived on Uist from North America and could remain until summer if they breed.
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."