Examples of Speckled Wood, White-Letter Hairstreak and Clouded Yellow species were among those spotted on the Hart to Haswell Walkway in Hartlepool.

Scientists have said some butterflies are moving northwards as a result of climate change.

The Speckled Wood was first seen in the area last year but the White-Letter Hairstreak had not been seen for years.

Hartlepool Council local nature reserves officer Joe Davis said: "The Speckled Wood is a butterfly which is slowly moving northwards due to climate change.

"The White-Letter Hairstreak hadn't been seen on the Walkway for several years, so many people thought it had long disappeared.

"We were especially thrilled to see a Clouded Yellow, which migrates from southern Europe in May.

"There are normally fewer than 500 seen each year in the whole of Britain, so it was an extremely rare sighting."