The travel history of a humpback whale spotted off the coast of Scotland has been tracked with the help of social media.

Humpback whales are known to make vast migrations between their breeding and feeding grounds, and are increasingly being seen in UK seas.

Now the first ever confirmed record of a UK-sighted whale hundreds of miles away in its summer feeding grounds in the high Arctic has been revealed, after its picture was spotted on Facebook by volunteer "citizen scientists".

Scientists studying the photographs and sightings of the whales in Scotland's Firth of Forth posted on social media believe the area is being used as a "service station" on their long journey from the Arctic to the Tropics.

The Firth of Forth appears to have become a winter hotspot for the giant marine mammals, with one humpback nicknamed "VYking" by local whale watchers due to its striking Y marking on the underside of its tail.

Volunteers from the Forth Marine Mammals Project, armed with a photograph of VYking who was one of four whales regularly seen in the firth in winter 2018, worked with scientists to see if they could find a record of the mammal elsewhere.

There was no sign of the humpback whale in scientific catalogues but a trawl through the internet by the volunteers turned up a picture on Facebook of VYking taken the previous summer off Svalbard, a Norwegian archipelago in the high Arctic.

The photo, which also shows the Y marking on the mammal's tail "fluke" or fin, was taken by a wildlife photographer 1,620 miles away from the Firth of Forth.

Scientists examined the photographs posted on Facebook by the volunteer project of whales spotted from the shore of the firth, finding 15 validated sightings with pictures between January 14 and March 15, 2017, and 36 between January 3 and February 23 in 2018.

In a study published in the journal Marine Biodiversity Records, the scientists say the photos of VYking provide the first confirmed record of a UK-sighted humpback whale in its Arctic feeding grounds.

The team also said a different individual, nicknamed Sonny, was identified from photographs taken in the Firth of Forth in both 2017 and 2018, providing the first evidence of a whale returning to the area in consecutive years.

This suggests some whales could be using UK seas as a "service station" to rest and feed on their long migration from their Arctic feeding grounds to their tropical breeding grounds, the researchers said.

Emily Cunningham, one of the marine biologists that led the study, said: "Until 2017, humpback whales had only been recorded a handful of times in the Firth of Forth over the past century - now we're seeing them every winter on an almost daily basis.

"UK seas are full of amazing wildlife, so keep an eye on the waves next time you're at the coast and please share anything you happen to photograph with your local wildlife organisation - it could be the start of a new discovery."

Daniel Moore, co-lead author, said: "This research shows that UK seas play an important role in the migrations of some humpback whales and demonstrates the need for effective conservation of our marine environment.

"We hope to continue our research in order to understand more about these movements and the importance of UK waters in contributing to successful migrations."

The Forth Marine Mammal Project, a community project established in January 2017, is led by volunteer citizen scientists who conduct watches from land year-round along both coasts of the inner Firth of Forth.