Bird watchers in Ulsan have reported sightings of two tundra swans, marking the first time the rare bird species has been found within the city, authorities said Monday.

The birds were found looking for food in the fields of Onyang-eup and Onsan-eup in Ulju-gun, Ulsan, on Feb.7, according to the Ulsan Metropolitan Government. The swans were first caught on camera by Lee Jae-ho, a member of the local youth bird watchers' club, who later accompanied photographer Yun Gi-deuk to photograph the birds.

Kim Seong-su, formerly a senior researcher at Kyungpook National University's Institute of Ornithology, said it marks the first time the tundra swan has visited the area. "Whopper swans visit Taehwa River (in Ulsan) every year, but this is the first time the tundra swan came (to Ulsan). ... It appears that the birds came to fields of Onyang in search of the abundant food sources there, in preparation for their northbound journey," Kim told local media.

Tundra swans are found across the globe, and those breeding in eastern Russia are known to spend their winter in the coastal regions of the Korean Peninsula, Japan, or southern China.

While it is a low conservation concern bird species worldwide, tundra swan sightings are rare in South Korea. The Korean government has included it on its list of endangered species.

The tundra swan is also designated a natural monument of South Korea, along with other species of the swan family including the whopper swan and mute swan.