Waterbirds are relatively permanent inhabitants of mangrove forests and can come from either the mainland or very distant regions as migrant species. These birds serve as an important indicator for preserving biodiversity in general by maintaining mangrove forests through rehabilitation and restoration activities. Additionally, some species have good economic potential to improve community welfare, as well as current pond products such as fish and shrimp. This study aimed to observe bird species diversity in the mangrove area to understand its function and recognize the migratory species that can be the basis for strengthening preservation or conservation. The research sites were in the Mahakam Delta, which is located in Muara Jawa and Sepatin, Kutai Kartanegara, Indonesia. More than 60 birds were successfully identified. Only one species was classified as CR (critically endangered), namely Thalasseus Bernstein. Meanwhile, bird species that were classified as VU (vulnerable) included Leptotilus javanicus, Fregata minor, and Egretta eulopheutes. Four species, including Anhinga melanogaster, Ichtyopaga ichtyaetus, Macronus ptilosus, and Numenius arquata, were identified as NT (near threatened) species. Most of the species found were characterized as having LC (least concern) status.