A playful dolphin in Australia that appears to prefer human company to other dolphins has surprised wildlife experts after frolicking with swimmers and surfers at some of Sydney’s most popular beaches.  The two-year-old female bottlenose dolphin has approached people in the water and spent hours playing with them, even if they showed little interest. It has allowed people to touch it and popped up around surfers, sometimes grabbing their leg ropes or jumping over their boards.