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 more than its estimate of 10,000 to 15,000 pounds. Caccia’s bird painting is exceptional for a number of reasons. Even though she was a prolific 17th-century painter, most of her commissioned pieces were religious frescoes and altarpieces, which are still in situ in Italy. Although she painted still-life subjects—Caccia is even credited as the first recorded painter of a floral still life in Italy—they number far fewer than her religious paintings. Most of Caccia’s work is in Montferrat, an area in the northwest region of Piedmont, Italy. But late last year, New York’s Metropolitan Museum …