VU
Bismarck Kingfisher Ceyx websteri



Justification

Justification of Red List Category
This species is judged to be Vulnerable on the basis of an estimated small population which is likely to be declining through habitat loss and degradation. However, researching its population size, tolerance of habitat changes and dispersal between subpopulations may lead to reclassification.

Population justification
The population is estimated to number 2,500-9,999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 3,750-14,999 individuals, rounded here to 3,500-15,000 individuals. Davis et al. in prep. suggest that there is a single sub-population on New Britain numbering >1,000 mature individuals,

Trend justification
Buchanan et al. (2008) calculated the rate of forest loss within the species's range on New Britain as 25% over three generations; however, the authors also noted that owing to indirect effects from logging (e.g. siltation) the rate of decline is probably higher than this, thus a rapid decline of >30% over three generations was estimated. Less detailed analysis is available for later years but about 2.2% of forest was lost plus 5.2% degraded across New Britain between 2002 and 2014 (Bryan and Shearman 2015). It is inferred that forest loss and degradation has slowed and the species’ rate of decline is precautionary retained 10-20% over three generations pending better data.

Distribution and population

This species is endemic to New Britain, New Ireland and the nearby islands of Umboi, New Hanover and Lihir in Papua New Guinea. There are few records of this species, all of single birds or a pair, but it was recorded on all five islands in 1997 (G. Dutson pers. obs. 1997-1998). There is also one sight record from Feni (I. Burrows in litt. 1999). It appears to occur along most suitable rivers, but many rivers are too fast or too large on these mountainous islands.

Ecology

This kingfisher inhabits small relatively slow-flowing rivers in lowland forest, often in patchy degraded forest and logged forest (K. D. Bishop in litt. 1994, J. Pilgrim in litt. 1999, Dutson 2011, Davis et al. in prep.). It has been recorded down to sea-level but its upper altitudinal limit may be only a few hundred metres (Gilliard and LeCroy 1967). It appears to be replaced by Common Kingfisher A. atthis along large sluggish rivers, mangroves and most lakes and is replaced by Variable Kingfisher Ceyx lepidus along smaller streams (Dutson 2011). It may occur beside forest-fringed lakes - there is one such record from Lake Hargy (Clay 1994), but no records from lakes with marshy or reedbed margins.

Threats

Its dependence on extreme lowland forest renders it susceptible to habitat changes from the extensive logging and forest clearance across its range. On New Britain, much of the flat lowland forest has been cleared for oil palm plantations. The major oil palm companies have committed to no further forest clearance but there is a risk that smaller companies will clear forest for oil palm. Industrial logging continues, as does clearance for subsistence gardens by the growing local populations. Although it has been recorded from degraded habitats (Davis et al. in prep.), it is likely to be affected by sediment run-off from logged and cleared areas into rivers.

Conservation actions

Conservation Actions Underway
None is known.

Conservation Actions Proposed
Conduct line-transects along rivers of varying size, water velocity, water turbidity, altitude and surrounding habitat. Survey all lowland lakes on New Britain. Investigate ecological separation from A. atthis. Map remaining forest and logging concessions across the Bismarcks. Lobby for a moratorium on forest clearance for oil-palm plantations. Enforce regulations protecting river courses in logging concessions. Encourage designation of large community-based conservation areas. Encourage creation of community-run sustainable logging rather than commercial logging.

Identification

22 cm. Medium-sized, river kingfisher. Greenish-blue upperparts, extending as slight partial collar onto pale buffy underparts. Black bare parts. Similar spp. Three similar but smaller species: Common Kingfisher A. atthis is greener above, more orange below and lacks the slight collar, Variable Kingfisher Ceyx lepidus is more purple above, brighter orange below and often with red on the bill, Little Kingfisher C. pusillus is purple-blue above and very small. Voice Louder, stronger and less sibilant than A. atthis. Hints Search medium-sized rainforest streams. Perhaps more common on small islands.

Acknowledgements

Text account compilers
Mahood, S., O'Brien, A., Derhé, M., Stattersfield, A., North, A., Dutson, G.

Contributors
Pilgrim, J., Dutson, G., Bishop, K.D., Burrows, I.


Recommended citation
BirdLife International (2019) Species factsheet: Ceyx websteri. Downloaded from http://www.birdlife.org on 24/05/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/05/2019.