After weeks of rain and wind in England, miserable penguins at a marine centre are being fed anti-depressants to cheer them up.

The 12 Humboldt penguins at the Sealife Centre in Scarborough, northeast England, were showing signs of stress as they shivered through one of the wettest winters on record.

Although the penguins are accustomed to cold weather in their natural habitat of Peru and Chile, the constant rain has come as a shock to them.

Keepers noticed they were tending to huddle together for warmth rather than plunging into the water.

So it was decided to slip pills into the fish they are fed on a daily basis.

"They are just not used to this type of constant, prolonged bad weather that we are having," a spokeswoman for the centre said.

"They are under treatment for stress and we hope the tablets will have a calming effect on them."

Lyndsey Crawford, the centre's display curator, explained that the pills were designed to stimulate normal behaviour in the penguins.

"Hopefully their instincts will kick in and they will realise they are not in any danger," she said.

The penguins have no idea that they are taking pills and suffer no discomfort as a result.

"They literally don't know anything about it. It's a tiny tablet that fits into the gill of the fish. It doesn't taste awful," she said.

The penguins were also seized by anxiety three years ago when a trespasser broke into their enclosure. The experience left the animals so frightened that they failed to produce eggs for some time.

Humboldt penguins are threatened with extinction in Peru and Chile due to a range of factors including climate change, the over-fishing of the species that they feed on and problems with becoming entangled in fishing nets.

The rainy winter in England has set records tumbling, being the wettest combined period for December and January since 1876-1877 and the second wettest since 1766, the Met Office has said.