Woodland Park Zoo officials said Monday they are expecting the arrival of its first orangutan baby in over three decades. Fourteen-year-old Sumatran orangutan Batu (bah-too) is nearing the end of her pregnancy, which is nearly nine months. The birth will mark the first orangutan born at the zoo in 35 years. According to the zoo, birth window calculations are based on estrus cycle, physical changes including weight gain, timing of mating and positive pregnancy test results. It is not possible to accurately predict a specific birth date for orangutans because of several factors, but officials said recent changes indicate it is approaching. Read more: https://www.king5.com/article/life/animals/woodland-park-zoo-expecting-first-orangutan-birth-35-years/281-36e292bb-0c00-42bc-922e-20796c3e867b