Justification
This species qualifies as Near Threatened as it has a moderately small population which is suspected to be declining moderately rapidly. If further research shows that the population is undergoing a more rapid decline, it may be uplisted to Vulnerable.
Taxonomic source(s)
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
Identification
20 cm. An inconspicuous, green fruit-dove. The male is uniformly green, although slightly darker on the back but with a yellowish-green head, a white belly and yellow undertail coverts. The female is similar but lacks the distinctive head plumage. Voice A single mellow whistle which is immediately followed by a short trill, the latter only heard at close quarters. Hints May be seen in any forest area of Kadavu and its offshore islands, generally heard first.
Distribution and populationPtilinopus layardi is endemic to the islands of Kadavu and neighbouring Ono in south-west
Fiji. In 2000, surveys found this species to be common in evergreen forests, with 53 birds recorded (mostly calling males) in 23.5 hours in a mixed lowland and montane site, and 17 birds in 15 hours at a montane site (G. Dutson
in litt. 2005)
, equating to 23 birds/km
2 and 11 birds/km
2 at these sites respectively, mostly calling males. There are a number of likely errors in this estimate, especially the number of silent birds overlooked and the species's higher abundance at lower altitudes (where calling males can be as little as 100 m apart (G. Dutson
in litt. 2005)
. The area of dense and medium-dense forest on Kadavu is around 225 km
2 (National Forest Inventory 1990-1993)
, suggesting that the total population is around 10,000 birds. However, the species also occurs on the island of Ono which probably constitutes a second sub-population (as this and other
Chrysoenas doves are rarely seen flying outside forest and have not been recorded from smaller islands), numbering about 5% of the total population (G. Dutson
in litt. 2005)
.
Population justificationRecent BirdLife Fiji surveys found this species to be common in evergreen forests, with 53 birds recorded (mostly calling males) in 23.5 hours a mixed lowland and montane site and 17 birds in 15 hours at a montane site. Estimating an average pace 1 km / hour and an effective detection distance of 50 m each side of the trail suggests that around 23 and 11 birds were detected per km
2 at these sites, mostly calling males. There are a number of likely errors in this estimate, especially the number of silent birds overlooked and the species' higher abundance at lower altitudes (where calling males can be as little as 100 m apart). The area of dense and medium-dense forest on Kadavu is around 225 km
2, suggesting that the total population is around 10,000 birds. However the species also occurs on the island of Ono which probably constitutes a second sub-population (as this and other
Chrysoenas doves are rarely seen flying outside forest and have not been recorded from smaller islands), numbering about 5% of the total population (G. Duston
in litt. 2005). In total the population is estimated to number at least 10,000 individuals, roughly equivalent to 6,700 mature individuals.
Trend justificationThe population is suspected to be declining based on rate of habitat loss. The population trend is estimated to be declining at the same rate as forest loss and degradation on Kadavu, which is estimated to be 0.5-0.8 % per year across Fiji (Claasen 1991), but probably higher on Kadavu which has suffered extensive fires in recent years. The population may therefore be declining at a rate that approaches 10% in ten years (G. Duston
in litt. 2005).
EcologyIt is generally found in well-forested areas in the lowlands; on Ono it is restricted to forest remnants (Clunie 1984)
, and is sometimes found in gardens (Watling 1982)
. It forages mainly in the substage of forests and in dense thickets.
ThreatsThe population is estimated to be declining at the same rate as forest loss and degradation on Kadavu, which has also suffered extensive fires in recent years. Hunting may be an additional threat.
Conservation actions underwayIn 2000, BirdLife Fiji conducted surveys to estimate population size.
Conservation actions proposedContinue to monitor population size to assess trends. Set aside and protect forest habitat, particularly in lowland areas. Investigate the impact of hunting on the species and regulate as appropriate.
Related state of the world's birds case studies
References
Watling, D. 1982. The birds of Fiji, Tonga and Samoa. Millwood Press, Wellington, New Zealand.
Clunie, F. 1984. Birds of the Fiji bush. Fiji Museum, Suva.
Claasen, D. R. 1991. Deforestation in Fiji: National environment management plan report 2.
Watling, D. 2000. Conservation status of Fijian birds. Technical Group 2 Report - Fiji Biodiversity Strategy and Action Plan.
Further web sources of information
Hear sounds for this species from xeno-canto, the community database of shared bird sounds from around the world.
View photos and videos, and hear sounds of this species from the Internet Bird Collection
Text account compilers
Benstead, P., Dutson, G., Mahood, S., O'Brien, A., Shutes, S.
Contributors
Dutson, G., Kretzschmar, J.
IUCN Red List evaluators
Butchart, S., Symes, A.
Recommended citation
BirdLife International (2013) Species factsheet: Ptilinopus layardi. Downloaded from
http://www.birdlife.org on 25/05/2013.
Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 25/05/2013.
This information is based upon, and updates, the information published in BirdLife International (2000)
Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004)
Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.
To provide new information to update this factsheet or to correct any errors, please email BirdLife
To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.