Data Zone
Justification of Red List category
This species has a very small range, leaving it vulnerable to threats, including habitat loss and degradation, which is ongoing within its range. There is no evidence, however, that the population trend is declining, nor that the species is confined to very few locations. It is therefore assessed as Near Threatened.
Population justification
The global population size has not been quantified, but the species is described as common in mature forest (Pratt et al. 1987, Steadman and Freifeld 1998, del Hoyo et al. 2007).
Trend justification
There are no data on population trends. The species may be affected by ongoing habitat degradation within the range, though it is unclear whether this is driving population declines.
Pachycephala jacquinoti is endemic to the Vava'u group and Late Island, Tonga.
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).
This species is restricted to remnant patches of mature forest and thought likely to decline if deforestation outpaces forest regrowth (Steadman et al. 1999). Conversion for agriculture has been a primary cause of habitat clearance in the past (Steadman and Freifeld 1998), however the species is now restricted to more inaccessible forest patches and remote sensing data are not available to detect current rates of forest loss (Global Forest Watch 2023, using data from Hansen et al. [2013] and methods disclosed herein). Non-native mammals occur throughout the range, including Pacific rat Rattus exulans and black rat R. rattus which are potential predators, and ungulates which overbrowse native understorey vegetation (Steadman et al. 1999, Boles 2020).
Conservation Actions Underway
No targeted conservation actions are known.
Conservation Actions Proposed
Conduct surveys to quantify the population size and trend. Monitor population trends. Protect remnant patches of mature forest. Control invasive species throughout the range.
Text account compilers
Vine, J.
Recommended citation
BirdLife International (2024) Species factsheet: Tongan Whistler Pachycephala jacquinoti. Downloaded from
https://datazone.birdlife.org/species/factsheet/tongan-whistler-pachycephala-jacquinoti on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/12/2024.