Tongan Whistler Pachycephala jacquinoti


Justification of Red List Category
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.

Population justification
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.

Distribution and population

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.


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).


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

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.


Text account compilers
Derhé, M., Mahood, S., O'Brien, A., Shutes, S., Stattersfield, A.

Recommended citation
BirdLife International (2019) Species factsheet: Pachycephala jacquinoti. Downloaded from http://www.birdlife.org on 19/07/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/07/2019.