Pachycephala jacquinoti 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Pachycephalidae

Scientific Name: Pachycephala jacquinoti Bonaparte, 1850
Common Name(s):
English Tongan Whistler
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Derhé, M., Mahood, S., O'Brien, A., Shutes, S., Stattersfield, A.
The species is classified as Near Threatened because it is suspected to have a moderately small population which is undergoing a gradual decline owing to habitat degradation. Further data on population size and trends is urgently needed for this species and may result in it being uplisted to Vulnerable.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Pachycephala jacquinoti is endemic to the Vava'u group of islands in Tonga, where it is reportedly common and widespread (Pratt et al. 1987, Steadman et al. 1999). More precise data on population size and trends would be very desirable.

Countries occurrence:
Additional data:
Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:2100
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:No
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The global population size has not been quantified, but the species is described as common (del Hoyo et al. 2007).

Trend Justification:  There are no data on population and trends. However, the species is suspected to be in decline owing to on-going habitat degradation.
Current Population Trend:Decreasing
Additional data:
Number of mature individuals:UnknownContinuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No
No. of individuals in largest subpopulation:100

Habitat and Ecology [top]

Habitat and Ecology:It is an understorey omnivore and forest obligate, and occurs in successional habitats only when adjacent to mature forest (Steadman et al. 1999). Since only very limited areas of native forest remain, it now occurs primarily in very steep or inaccessible places, coastal littoral areas and swamps (Thistlethwaite et al. 1993).

Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):6.7
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): A varying set of non-native mammals occurs on each of the 16 islands of Vava'u, including Pacific rat Rattus exulans and black rat R. rattus which are likely predators, and ungulates which over-browse native understorey vegetation (Steadman et al. 1999). If deforestation outpaces forest regrowth, the population of P. jacquinoti will surely decline (Steadman et al. 1999).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
None is known.

Conservation Actions Proposed
Investigate population size so that future trends can be elucidated. Compare the abundance of the species on islands with different predator suites so that their relative effects can be evaluated. Instigate a community education programme to promote animal husbandry practices which minimise disturbance to native forests. Consider protecting a suitable tract of native forest.

Citation: BirdLife International. 2016. Pachycephala jacquinoti. The IUCN Red List of Threatened Species 2016: e.T22705510A94021921. . Downloaded on 26 September 2018.
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