Bibi shows signs of labor as the Cincinnati Zoo awaits Fiona's sibling

Cincinnati Zoo officials said they don't believe she'll give birth right away, but that Fiona could become a big sister soon. The baby's estimated due date is August 15, but caretakers said a hippo's birth window could be 30 days before or after that estimation — meaning Bibi's baby becoming born as early as now or as late as September 14.