Last year, an Italian nun caused quite a stir at Sotheby’s, London, when her painting titled “Still Life of Birds, Including a Marsh Tit, Chiffchaff, Chaffinch, Blue Tits, Goldrest, Lapwing and a Great Tit” fetched far more than estimated. The Renaissance painting by mannerist painter Orsola Maddalena Caccia sold for 212,500 pounds ($264,350), 14 times…