Seven more alala, or Hawaiian crows, have been released into the Puʻu Makaʻala Natural Area Reserve on the windward slopes of Mauna Loa this month, according to wildlife officials.

They join about 20 others that have been released into the Hawaii island forest over the past two years as part of The ‘Alala Project, an ongoing effort by the state, San Diego Zoo Global, and the U.S. Fish and Wildlife Service, to reintroduce Hawaii’s only native crow species back into the wild.

Among the seven young crows released are five males and two females.

Students from Hawaii island schools named the newly released birds through a contest. The names chosen are: Kalokomaikaʻi, Keolamauloa, Eola, Kamanuolamau, Kalaʻau, ʻAlohi, and Kanaʻi.

Kalokomaikaʻi, one of the male birds, was initially released in 2017 but had to be recaptured and rehabilitated following an injury in the wild.

This month, observers from the project also documented several major milestones among crows released in 2017 that offer hope these captive-bred birds will survive.

Three pairs of birds appeared to have developed pair bonds. Two pairs were observed nest-building, and one of the females, Manaiakalani, sat on her nest for several weeks. Her male partner, Manaʻolana, was seen providing her with food on the nest.

No hatching was observed, but the pair continued to hang out near their nest, and to defend the territory around it.

“‘Alala form complex bonds as breeding pairs and must work together to build their nests,” Alison Greggor, a postdoctoral research associate with San Diego Zoo Global, said in a news release. “Having released alala engage in the full suite of breeding and nest building behaviors in their first season as adults represents a huge step forward for the program and their recovery as a species.”

Once found across Hawaii island, alala became extinct in the wild. A pair of alala was last observed in 2002 in South Kona.

Since the first captive-bred alala were released into the forest in 2017, two have been killed by predators. One was killed by a Hawaiian hawk, and the other by an unknown predator.