The Duke and Duchess of Cambridge occasionally take advantage of the shared bikes available in London when they are in the city, a spokesman says. The couple spend most of their time in Wales, where Prince William pilots rescue helicopters as a flight lieutenant in the Royal Air Force. The spokesman said they use Barclays Cycle Hire for "private journeys" when they are staying in their apartment in Kensington Palace, The Independent reported. The bicycles are available at more than 400 docking stations around London for modest fees payable by credit or ATM card. The scheme was first envisioned by Mayor Kenneth Livingston, although the bicycles have been nicknamed "Boris Bikes" after the current mayor, Boris Johnson.