Large crested ibis flock seen on Sado Island

12 crested ibises released into the wild after being raised in captivity have formed a flock on Sado Island, off the Sea of Japan coast. The flock is the biggest in Japan.

The Japanese Environment Ministry says the 12 birds -- 6 male and 6 female -- were seen eating together in rice fields near Sado City early Friday morning.

Last year, 10 crested ibises were released into the wild but all the females crossed the sea to the main island of Japan while the males remained on Sado Island during mating season.

But this year, after 20 more birds were released in September, the crested ibises have been spending more time together.

Environment Ministry official Kohei Sasano says he want to closely monitor the flock as crested ibises breed from now until spring.

The birds are designated a national treasure in Japan where they disappeared from the wild in 1981.