Brookfield Zoo prepares to welcome 2 dolphin calves

On the heels of the sudden death of a newborn bottlenose dolphin last year, Brookfield Zoo is now expecting two dolphin calves later this year. Two adult female dolphins, Allison and Allie, are both pregnant, zoo officials announced Wednesday. Allison is due late this summer or early fall, while Allie is due later in the winter. An exact due date hasn't been determined, but the dolphins are being closely monitored through blood tests and ultrasounds, and the fetuses look healthy and are…