• Summary
• Text account
• Data table and detailed info
• Range map
• Resources

Taxonomic note

Lalage leucomela and L. conjuncta (del Hoyo and Collar 2016) were previously lumped as L. leucomela following Christidis & Boles (2008) and Sibley & Monroe (1990, 1993).

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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	B1ab(ii,iii)+2ab(ii,iii)

Red List history

Year	Category	Criteria
2023	Vulnerable	B1ab(ii,iii)+2ab(ii,iii)
2016	Vulnerable	C2a(ii)
2012	Not Recognised
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	not a migrant	Forest dependency	medium
Land-mass type		Average mass	30 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	412 km2
Area of Occupancy (breeding/resident)	412 km2
Number of locations	6-15	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	-	suspected	2017-2027
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-15%	-	-	-
Generation length	3.49 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: This species is very poorly known and the population size has not been quantified. It is currently only known from a very limited number of specimens and field observations, but may be locally common (Dutson 2011). The last documented record of this species is a specimen collected in 1979 (LACM 91065, per Rutt et al. in prep), though there have been a number of unconfirmed records since. It was not recorded by rapid surveys in 2014 suggesting that the species is potentially very rare and restricted to higher altitude or localised areas (Aplin et al. 2015).

Trend justification: There are no data on population trends, but extensive logging is continuing on the island (Taylor 2020). Although the species is poorly known, it is thought to be restricted to closed forest (Dutson 2011, Aplin et al. 2015) and is precautionarily suspected to be declining as a result. In the three generations to 2022, remote sensing data indicate that c.5% of forest was lost in this species' range (Global Forest Watch 2023, using data from Hansen et al. [2013] and methods disclosed therein). The rate of forest loss has rapidly accelerated in recent years however, reaching an equivalent rate of c.10% in three generations based on losses in 2017-2022. Based on even steeper losses in 2022 alone, forest loss may continue at a rate equivalent to c.20% within three generations if this is ongoing. Assuming declines are roughly equivalent to the rate of forest loss, they are tentatively placed in the range 1-9% in the past three generations, 1-15% between 2017 and 2027 and 1-19% over the future three generations.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Papua New Guinea	extant	native	yes

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	0 - 600 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Sus scrofa	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation

Purpose	Scale
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2025) Species factsheet: Mussau Triller Lalage conjuncta. Downloaded from https://datazone.birdlife.org/species/factsheet/mussau-triller-lalage-conjuncta on 05/01/2025.
Recommended citation for factsheets for more than one species: BirdLife International (2025) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 05/01/2025.