• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Justification of Red List category
This enigmatic species is extremely poorly known, hampering efforts to assign its conservation status. It has a moderately small range and is probably declining owing to introduced predators and forest degradation. For these reasons it is classified as Near Threatened.

Population justification
The global population size has not been quantified, but the species is reported to be locally common (Baker 1997).

Trend justification
There are no data on population trends, but this species is suspected to be in decline owing to habitat degradation and predation by introduced carnivores.

Horornis haddeni is endemic to the island of Bougainville, Papua New Guinea. It has only recently been described, although its existence has long been known to the local population (Lecroy and Barker 2006). Since 1972, ornithologists have been aware of its presence, but only through its voice (Lecroy and Barker 2006). Years of civil war prevented fieldwork in the 1990s and it was not until 2000 that the first individual was mist-netted (Lecroy and Barker 2006). A further two individuals were caught within a few months; thus the species is assumed to be fairly widespread and not uncommon in suitable habitat (Lecroy and Barker 2006). However, others have found it to be absent from the highest altitudes, and it may therefore only occur within a relatively narrow altitudinal band (B. Beehler in litt. 2007). Tracewski et al. (2016) estimated the maximum Area of Occupancy (calculated as the remaining forested area within the species's range) to be c.380 km².

It inhabits montane forest at 700-1,500 m. Reported to forage mostly on the ground, sometimes in association with Island Thrush Turdus poliocephalus (Dutson 2011).

No specific threats are known; however, it is probably threatened by small-scale clearance of forest for agriculture and from predation by introduced Black Rats Rattus rattus and feral cats.

Conservation Actions Underway
None is known.

Conservation Actions Proposed
Survey to reveal the upper and lower elevational limits of the species's range. Protect significant areas of high elevation forest in the form of community conservation areas. Research the effects of introduced predators on the species.

Text account compilers
Westrip, J., Mahood, S., Wheatley, H., Derhé, M.

Contributors
Beehler, B.

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Recommended citation
BirdLife International (2024) Species factsheet: Bougainville Bush-warbler Horornis haddeni. Downloaded from https://datazone.birdlife.org/species/factsheet/bougainville-bush-warbler-horornis-haddeni on 23/11/2024.
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 23/11/2024.