Sir Paul McCartney is selling off one of his beloved Martin guitars to help conservationists save African elephants.

The Martin D-28 left-handed guitar, which MCCartney has signed, went up for auction on eBay.com on Wednesday (13Aug14).

Proceeds from the sale will benefit the Nature Conservancy's African Elephant Initiative. Bidding began at $10,000 (£5,900).

Alongside his signature, the former Beatles star - a keen animal activist - wrote, "This guitar saves elephants."

David Banks, the managing director of the The Nature Conservancy's Africa Program, says, "To have Sir Paul's support and working with Martin Guitar is a real honour. This calibre of collaboration will make a difference to help end the worst poaching crisis in history."