The twin Sumatran tiger cubs born at the Dallas Zoo early last month officially have names, the zoo announced this week.

While the zoo animals are usually named after their personalities, the little boy and girl were named after environmentalists working to save their critically endangered species. Tigers are native to the island of Sumatra in western Indonesia, where only around 400 to 600 remain.

Nety, the little female, owes her name to Nety Riana Sari. Sari works with the World Wildlife Fund The Thirty Hills project, which restores deforested areas in Sumatra. The project also sets aside land for local communities to use to generate income.

The other teddy bear is named Rudi after Rudi Putra, director of the Leuser Conservation Forum and one National Geographic Fellow 2019.

The forum works to protect and restore the wildlife and forests of Sumatra, home to one of the last intact rainforests in Indonesia. The region is also the last place on the planet where rhinos, elephants, tigers and orangutans live together in the wild.

Nety and Rudi were born at the zoo on December 6 to mum Sukacita and dad Kuasa. Their older sister Sumini is also named after an environmentalist who works to preserve forests in Indonesia.