Ko'ko' chicks born in Virginia could be released on Guam next year

Two Guam rail chicks, hatched earlier this month at the Smithsonian Conservation Biology Institute in Virginia, could make it back to Guam next year to be released into the wild, according to a news release from the institute.

The flightless birds are native to Guam and are known locally as ko’ko’.

When the two ko'ko' are repatriated, they will join some 200 birds living in the wild in Guam and Rota, according to the conservation institute. About 116 ko'ko' live in human care.

This is the first time in over 30 years that there are more ko'ko' in the wild than in human care, according to the institute.

The ko’ko’ chicks hatched Nov. 14, born to a female ko’ko’ that never successfully raised chicks before, the release stated. Institute officials said the chicks' father was an experienced parent.

“Keepers hoped that by pairing them together, both would successfully care for the chicks,” the release stated.

The chicks’ parents were slowly introduced to each other during the summer, with handlers keeping close watch over them. Officials stated that the pair “displayed affiliative behaviors” toward each other and began foraging for food together and spending time near each other.

“Soon after, they laid their first clutch of eggs,” the news release stated.

Bird keeper Erica Royer said it was rewarding to see the two chicks hatch.

“We worked really hard to introduce their parents to each other and to help them raise their chicks. Luckily, all of our work paid off and these two chicks will be living in the wild soon, which is our ultimate goal,” Royer said.

Intervention

In the first days of the birds hatching, keepers intervened to increase the chicks' chances of survival, feeding them chopped meal worms and meat twice a day. The chicks gained an ideal amount of weight over their first four days, which indicated to keepers the parents were properly caring for them and human intervention was no longer needed, according to the release.

In coming weeks, the ko’ko’ chicks will shed their black downy feathers and their signature brown feathers will come in. After a month, the chicks will be independent from their parents, according to the institute.

The handlers will be able to find out the sexes of the chicks by analyzing a genetic sample from their feathers.

According to the institute, it’s easy to tell the chicks apart because one is larger and “more assertive when seeking out food.” The other is smaller and more cautious.

Killer snake

The brown tree snake almost wiped out the ko’ko’ population on Guam years ago. In 1984 the last 21 birds in Guam were taken to start a recovery program, the release stated.

The Smithsonian Conservation Biology Institute first received some ko’ko’ to be part of the recovery program in 1985 and all the chicks hatched at the institute are meant to be reintroduced to the wild in Guam.

Most recently, in September two female ko’ko’ were taken to Rota to live in the wild.

A small population of ko’ko’ also lives on Cocos Island, where there aren’t any brown tree snakes, according to the institute.

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