Remarkable rail discovered "just in time"

17-08-2004

Exactly one hundred years after the last visit by an ornithologist, a team of bird, mammal, reptile and amphibian specialists arrived in May this year on the island of Calayan, one of the Babuyan Islands in the northernmost part of the Philippines archipelago. There, they made the remarkable discovery of a new species of rail, which they have named the Calayan Rail Gallirallus calayanensis. (The formal description appears in Forktail 20: 1–7, published by the Oriental Bird Club.)

Like its closest relative, the Okinawa Rail G. okinawae from Okinawa Island, 1,000 km to the north in the Ryukyu Islands, Japan, the new species appears to be almost flightless. The two species closely resembles one another in size and structure.

The Babuyan Islands Expedition was jointly led by Carl Oliveros and Genevieve Broad, who had both previously worked on a WWF project to conserve humpback whales in the waters around the island. They had the support of the Mayor of Calayan, who wants the island and its surrounding waters to be made a protected area.

Just before noon on 11 May 2004, Carmella Espanola was walking through a clearing and heard unfamiliar calls that drew her attention to a group of four rails in the undergrowth. Shortly afterwards she watched two birds cross the trail and begin feeding. They were all dark, with orange-red bill and legs and appeared to be the same size as Barred Rail G. torquatus, a common species on the island.

Carmella took notes and photographs, and recorded the calls. But her account of the sighting had Des Allen, an expedition member and expert on oriental birds completely stumped. Next day he went to the same area, and heard unfamiliar “loud, rasping trumpeting calls”, interspersed with the calls Carmella had recorded. He played back her recording, and a bird answered it and later he saw the unmistakable silhouette of a medium-sized rail. Returning towards camp, Des heard the calls again in an area of primary forest. This time, playback attracted a rail to within two metres of where he stood. From the uniform dark plumage, red legs and medium-length red bill, Des knew that this was something unknown. Later that day he made a short video-recording of one of the rails, and showed it to the other team members. Over subsequent days, the team observed the birds many times. In fact, the number of sightings indicated that the rail was quite common in the area. Discussions with local people established the rail was well known to them, and had a local name of “piding”.

Carmela Española

The rail lives among the dense undergrowth of the island's forests
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"The discovery of the Calayan Rail is a wonderful demonstration that the world has much to reveal to us yet. However, these newly discovered species are nearly always at risk from human influence, because most are on islands or mountains, where their ranges are naturally quite small. The Calayan Rail is another species that we have discovered just in time, another case for long-term care by human society." —Nigel Collar, BirdLife International

The rail appears to be restricted to forests on coralline limestone areas, which probably make up less than half the island’s surface, and the extent of their suitable habitat is likely to be much less than 100 km², and could be smaller than 10 km². Des suspects they are abundant, but very localised.

Although the rails are occasionally caught in chicken snares, they are not directly hunted. However, work to build a road around the island, and from Poblacion to the centre, has already begun. These roads may encourage the spread of settlements, and people will bring introduced predators — cats, dogs and rats — along with them.

On the basis of its small currently known population and range size, the Calayan Rail appears to qualify as Vulnerable on the IUCN Red List of threatened species. It is likely to become more threatened in the future, and action is needed to pre-empt potential threats to the bird and its habitat.

The expedition team plans further research to determine the habitat requirements, distribution and population of the Calayan Rail. They will work closely with the local community to minimise threats, and encourage long-term initiatives to protect the forest. Genevieve Broad said the Calayan islanders are concerned about the future of the island’s environment and natural resources. “I hope this discovery will bring the recognition these islands deserve, as an important site of biological diversity,” she said.