Calayan Rail Gallirallus calayanensis


Justification of Red List Category
This recently described species is listed as Vulnerable, as it has a very small population and a very small known range. At present it is not known to be declining, but if any evidence of a decline emerges, then it will warrant uplisting to Critically Endangered.

Population justification
Allen et al. (2004), estimated 100-200 pairs. It has since been found to be locally common, with an estimated area of occupancy of 36 km2. However recent species distribution modelling estimated its area of occupancy at 90.2 km2 (C. Layusa and C. Oliveros in litt. 2012). These latest estimates based on species distribution modelling and known densities put the population size at 3,800–6,500 individuals (C. Layusa and C. Oliveros in litt. 2012), equating to 2,500-4,300 mature individuals.

Trend justification
The population is suspected to be stable in the absence of evidence for any substantial declines or threats.

Distribution and population

This species is endemic to Calayan island in the Babuyan islands, northern Philippines, where it was recorded and a specimen collected from Longog, Barangay Magsidel, in May 2004. It was found to be common within its preferred habitat (at an estimated density of one pair per 1-2 ha), and its population has been estimated at 100-200 pairs in the area surveyed. Follow-up surveys in 2005/2006 confirmed that the species is well distributed but localised across the island and recorded a total of 202 individuals from 471 playback stations (Española and Oliveros 2006). Surveys conducted since 2005 had detected an apparent decline of 14% in detectability by 2008; however, further data are required in order to more robustly analyse the population trend (Oliveros and Layusa 2008). The range-wide surveys of 2005/2006 estimated a total area of occupancy of 36.4 km2 out of 73.6 km2 total area surveyed. However species distribution modelling recently estimated the area of occupancy at 90.2 km2.


Initially thought to be restricted to primary and secondary forest on areas of coralline limestone that is permeated with sink-holes and caves, the species has since been regularly observed in non-limestone forest. Within this habitat it has even been recorded in degraded areas with young secondary growth of low trees. It is also seen in coconut plantations with thick fern undergrowth adjacent to forest. It appears to prefer areas near streams, but the strength of the association is unknown. It has not been recorded in other habitats on the island, including rice-fields or open clearings. The type specimen was collected at an altitude of 300 m. The species forages by pecking at the ground, occasionally overturning leaves, and appears to be flightless, or nearly so. At least one example of this species's nest has been recorded (Oliveros and Layusa 2011). It was located on the ground at the base of a fig tree, having been constructed with dried leaves and stems, and contained three eggs (Oliveros and Layusa 2011).


In those parts of the island with forested coralline limestone outcrops, the soil is often very thin or absent, and hence unsuitable for agriculture. However, in areas surveyed during 2005/2006, an estimated 8.2 ha of primary forests have been converted to farmlands with 4.7 ha comprising newly cleared forests that are being prepared for slash-and-burn farming or kaingin (Española and Oliveros 2006). Some unregulated subsistence logging on the island is likely to remove suitable habitat (Española and Oliveros 2006). Analysis of satellite images from 1979 and 2006 showed an 8% decline in forest cover on Calayan Island, which could mean an 8-27% decline in the species’s range over this period (C. Layusa and C. Oliveros in litt. 2012).

The species seems tolerant of degraded habitat, and the human population of the area is very low. The species is occasionally caught in traps set for Red Junglefowl Gallus gallus, but is not directly targeted. Following publicity about the species it was recorded in captivity and there are concerns that local trade may have a detrimental impact (Española and Oliveros 2006). Introduced predators such as dogs and cats are largely absent. However, the construction of a road around the periphery of the island is in progress. These roads may encourage the spread of settlements, and hence dogs, cats and rats, could threaten the species. The construction of roads crossing through the island’s forested interior started in 2006 but has been discontinued. Rails have been observed crossing some of these cleared paths during subsequent surveys (Oliveros in litt. 2012). Plans for tourist developments are yet to materialise, but they may constitute a future threat (C. Española in litt. 2010).

Conservation actions

Conservation and Research Actions Underway
The Calayan municipal council has passed Municipal Ordinance No. 84, which prohibits the capture, sale, possession and collection of the species (Española and Oliveros 2006). Conservation is already being promoted in the Babuyan islands, with environmental awareness being promoted in schools since 2001, and work is in progress to declare the islands of Calayan municipality and the surrounding waters a protected area. A consultative workshop themed Conservation of the Calayan Islands' Natural Heritage was held in October 2005 to identify key communication and education activities needed to raise local conservation awareness and cooperation (Española and Oliveros 2006). Community consultations in May 2006, with participation by local stakeholders, resulted in a conservation action plan that specifies measures to control slash-and-burn farming, provide livelihood assistance to locals, intensify information and education campaigns, establish a protected area or sanctuary, and strengthen enforcement of environmental laws (Española and Oliveros 2006)

The Calayan Rail Project, conducted by Isla Biodiversity Conservation Inc. (ISLA), was promoted at the Philippine Bird Festival and has received additional media coverage (Española and Oliveros 2006). Since 2007, local stakeholders, mostly young people from Calayan, have been trained in rail survey methods and protocols (Oliveros and Layusa 2008). Awareness-raising campaigns have been conducted in primary and secondary schools, and posters and factsheets have been distributed to communities members and local government staff. An environmental law seminar has been held and the Calayan Environmental Council has been established to formulae policies and implement programmes (Oliveros and Layusa 2008). Consultations have also been held with stakeholders on the establishment of a wildlife sanctuary at Sitio Longog (ISLA Biodiversity Conservation 2008, Oliveros and Layusa 2008). In 2011, the Calayan municipal council passed an ordinance establishing the Calayan Wildlife Sanctuary, covering an area of 29 km2 of forest in the island’s interior (Layusa in litt. 2012). 

Conservation and Research Actions Proposed

Further research is needed to clarify the habitat requirements, range size and population size of the species. Promote the establishment of an environmental monitoring system. Conduct further community consultations and education campaigns. Set up a volunteer network for conservation activities. Develop capacity of local officials and community leaders in managing the recently-established wildlife sanctuary and in enforcing its rules and regulations.


The rail is all dark (very dark brown) with a stout orange-red bill and orange-red legs. Voice Produces loud, rasping trumpeting calls. Similar spp It is structurally very similar to Barred Rail Gallirallus torquatus but differs greatly in plumage (C. Layusa and C. Oliveros in litt. 2012).


Text account compilers
Bird, J., Harding, M., Taylor, J. & Ashpole, J

Allen, D., Española, C., Layusa, C. & Oliveros, C.

Recommended citation
BirdLife International (2021) Species factsheet: Gallirallus calayanensis. Downloaded from on 04/03/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from on 04/03/2021.