FORT WORTH, T.X. (WNCT) — The Fort Worth Zoo announced the birth of four endangered gharial crocodiles, which they called a “monumental conservation success,” on Thursday, August 31.

The zoo is the only institution to have produced multiple offspring of the species in the United States, with only one other institution having produced a single hatchling in 2016, according to the Fort Worth Zoo.

It’s estimated that there are only 200 reproducing adults of the species remaining in the wild, Fort Worth Zoo said.

The gharial crocodile is critically endangered due to factors such as sand mining, pollution, and river fragmentation, the zoo said.

Currently, the crocodiles will live “behind the scenes” at the zoo so that their growth can be monitored by staff, according to the zoo.

Footage provided by Fort Worth Zoo gives an up-close look at the hatchlings.