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

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.
Dutson, G. 2006. The Pacific shrikebills (Clytorhynchus) and the case for species status for the form sanctaecrucis. Bulletin of the British Ornithologists' Club 126(4): 299-308.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	C2a(ii)	B1ab(ii,iii,v)+2ab(ii,iii,v); C2a(i,ii); D1

Red List history

Year	Category	Criteria
2022	Endangered	C2a(ii)
2016	Endangered	B1ab(ii,iii,v); C2a(ii)
2012	Endangered	B1ab(ii,iii,v);C2a(ii)
2008	Endangered	B1a+b(ii,iii); C2a(ii)
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	not a migrant	Forest dependency	high
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	670 km2	medium
Area of Occupancy (breeding/resident)	300 km2
Number of locations	6-20	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	250-999 mature individuals	poor	estimated	2016
Population trend	decreasing	poor	inferred	-
Generation length	3.9 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The species is currently thought to be very rare and is currently known from only one area on Nendo, although it is suspected to occur at others. It is known from two specimens taken in 1927, two pairs seen in 2004 (Dutson 2006) and two pairs seen in 2014 (Pierce 2014); other short surveys have failed to find the species, though these did not reach hill forest in interior Nendo (Mayr 1933, Gibbs 1996, G. Dutson pers. obs. 1997, T. Leary in litt. 2000). This species appears to be restricted to old-growth forest, in which there are two indications of population density: two pairs along a 10-km transect (Dutson 2006) and 0.4 birds per hour (Pierce 2014). This is in spite of reasonable detectability once pairs were found (Pierce 2014). Approximated densities and encounter rate are also similar to the similar Black-throated Shrikebill C. nigrogularis in Fiji, which was recorded at an average of 0.1 birds (mostly calling males)/hour in old-growth forest, equating to one pair/km² (G. Dutson in litt. 2005). Applying a density of  one pair (two mature individuals) per km², and a total area of 470 km² of forest in 2021 (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein), the population is estimated to be a maximum of 940 mature individuals. However, large areas of forest appear not to be occupied (G. Dutson in litt. 2022), and the population size is therefore estimated at 250-999 mature individuals, however it may possibly even number <250.

Trend justification: This species appears to be confined to old-growth areas of good forest and is absent from all degraded habitat types including secondary forest and gardens (Pierce 2014, G. Dutson in litt. 2021). Since the island was once entirely old growth forest, and the species now appears absent from these areas, declines are inferred to have taken place in the past. Habitat degradation on Nendo is ongoing (Global Forest Watch 2022, using Hansen et al. [2013] and methods therein) and the western side of the island is now replete with logging tracks (Global Witness 2018, M. O'Brien in litt. 2021) that may accelerate these losses in the future. The impacts of rats (Rattus rattus) and Wasmannia fire ants are unknown but concern, especially on the latter, has been raised (R. Pierce pers. comm., M. O'Brien in litt. 2021). The rate of ongoing declines is, however, unknown and requires urgent confirmation given the small population size of this species.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Solomon Islands	extant	native	yes

Country/Territory	IBA Name
Solomon Islands	Nendö

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Altitude	0 - 500 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Unknown		Unknown
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Wasmannia auropunctata	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Reduced reproductive success

---

Recommended citation
BirdLife International (2024) Species factsheet: Nendo Shrikebill Clytorhynchus sanctaecrucis. Downloaded from https://datazone.birdlife.org/species/factsheet/nendo-shrikebill-clytorhynchus-sanctaecrucis on 22/12/2024.
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 22/12/2024.