Have you spotted the rare black swans at Milton Keynes lake?

The swans, which appear to be a breeding pair, were seen over the weekend by a member of the public who quickly snapped some photographs.

She said: “I didn’t realise quite how rare they are until I looked it up when I got home.”

The black swan is the official bird of Western Australia and is featured on the flag of this state and in its coat of arms.

They were first brought to the UK in 1791 as ornamental birds, along with golden pheasants and peacocks, to feature in zoos and private collections. But a handful escaped and bred. By 2005 there were fewer than 20 breeding pairs in the UK but now, 17 years on, it is thought this has increased to 120 pairs.

Sightings have been made in around 200 different locations across the country. The biggest cluster can be found in Dawlish Warren in Devon and they are the emblem of this town.

Though the black swans (officially known as Cygnus atratus) appear to be jet black, they actually have white primary wing feathers, which can be seen when they are in flight.

They are similar in size to the closely related mute swan and their bills are red with a broad white band on the tip.

The black swan makes a musical, bugle-like sound as well as a range of softer crooning notes. It can also whistle, especially if disturbed while breeding and nesting.