Van Gogh and Picasso face no artistic challenge from Ivan the gorilla (pictured), but the Zoo Atlanta mainstay isn't a slouch when it comes to painting, either. At a recent charity auction, one of the 46-year-old silverback's works fetched $2,500. "Ivan picks the color he wants and I put the paint on the canvas and he paints," says Jodi Carrigan, one of Ivan's keepers. "Then he signs each one with his fingerprint." Paintings by Ivan and other gorillas and orangutans from Zoo Atlanta will be on display at APES IN THE ARTS, a fundraising auction Thurs., MARCH 6, benefiting the Dian Fossey Gorilla Fund, which is headquartered in Atlanta, and orangutan organizations. $30-$40. 7 p.m. J. Tribble Antiques, 747 Miami Circle. 404-846-1156. www.apeconservationeffort.com.