Rukmini, one of the female hippopotami at the Thiruvananthapuram zoo, has become the cynosure of all eyes after she gave birth to a calf on Wednesday. It is her fourth offspring. With this birth, the number of hippos in the zoo has gone up to seven. According to zoo authorities, the calf appears to be in sound health. Adding a bit of novelty was the birth in the afternoon since the animal almost always gives birth at night. For the next few days, animal keepers will keep a close watch on the calf to ensure that it continues in good health.