Keepers routinely take DNA samples from newborn orangutans because the endangered great apes are part of a breeding program. Researchers at Basel University's forensic laboratory compared Padma's DNA to that of Budi, a 14-year-old male living in the same enclosure as the baby's mother, Maja.
They found it didn't match Budi's DNA. Instead, it matched 18-year-old orangutan Vendel, who lives in the next enclosure. It appears that for Maja and Vendel, the dominant male at Basel Zoo, the dividing fence was no obstacle to some monkey business.
Basel Zoo: https://www.zoobasel.ch/en/aktuell/index.php