DD
Tagula Butcherbird Cracticus louisiadensis



Justification

Justification of Red List Category
This species is endemic to Tagula Island and three small neighbouring islands, Papua New Guinea. It has only recently been studied and its current classification as Data Deficient needs to be revised.

Population justification
Pre-dawn singing males surveyed during the breeding season occurred at densities of about 0.26 males/ha on Sabara Island (W. Goulding in litt. 2016). The species is more patchily distributed on Panawina (0.15/ha), Junet (0.23/ha) and Tagula (0.18-0.23/ha) where it appears to be at lower densities in suitable habitat and absent from some areas of suitable habitat. Conservative extrapolation using forest cover greater than 80% (Hansen et al. 2013) combined with the observed densities, suggests that the global population of mature individuals is 10,000-15,000 (W. Goulding in litt. 2016).

Trend justification
Slow decline caused by slow ongoing forest loss and degradation (e.g. Hansen et al. 2013)

Distribution and population

Cracticus louisiadensis is endemic to Tagula (= Sudest) Island (c.800 km2), Junet (=Panatinani) Island (c. 77 km2), Panawina Island (c.  29.5 km2) and Sabara Island (c. 4 km2) in the Louisiade Archipelago of Papua New Guinea (Coates 1990; W. Goulding in litt. 2016). It is absent from the intervening islands of Nimoa, Grass and Hemenahei (W. Goulding in litt. 2016). Ten were seen during a 10-day trek from the north coast up to Mt Riu in 1992 (I. Burrows in litt. 1994). More were heard on Sabara Island and observed on Tagula Island up to about 500 m in 2004 (Pratt and Beehler 2015).

Ecology

Its population and ecology are not well known but it is dissimilar to the allospecific Hooded Butcherbird C. cassicus, a sister species (Kearns et al. 2013) which is a common and adaptable species, occurring in all forest edge habitats including gardens and savanna (Beehler et al. 1986). This species is more restricted to forest interior and adjoining forest edge, particularly tall trees for pre-dawn singing during the breeding season. Forages in and near mangroves and secondary habitat when these habitats are adjoining contiguous forest. Generally avoids sago stands or isolated and small forest patches (W. Goulding in litt. 2016). It is absent from heavily fragmented landscapes lacking contiguous forest cover, and absent near some large human populations and areas with a history of past disturbance, e.g. old coconut plantations on NW of Tagula Island (W. Goulding in litt. 2016). Occurs at relatively high densities on Sabara, despite this island having a large and growing human population, but it is an uplifted coralline island unsuitable for subsistence farming. Vocal differences between individuals from Sabara and other islands, suggest distinct subpopulations.

Threats

Over half of the forest on Tagula is already degraded and logging must remain a threat to all the lowland forest (Beehler 1993). Forest loss between 2000 and 2014, caused largely by subsistence gardening, was 1.7% on Sudest Island, 4.1% on Junet Island, 2.2% on Panawina Island and 0.3% on Sabara Island (Hansen et al. 2013). Forests on Junet and Panawina are under increasing pressure from subsistence agriculture from growing human populations on Grass and Sabara Islands. Commercial gold prospecting has been occurring in forests of Sudest Island in recent years. Changing climate and more extreme weather events such as cyclones pose a threat to forest integrity and resources for this species (Goulding et al. 2016a). Around Araetha village on the northcoast of Sudest Island, the number of breeding pairs dropped from five to three after Cyclone Ita (W. Goulding in litt. 2016). Individuals disappeared that were known by local people to have called from particular locations for numerous years. Human hunting may have played a role in the decline of this species in other areas, as inferred from one report of a singing bird killed with a slingshot on Junet in 2013, and the absence of the species from areas of suitable habitat in which people had hunted with rifles. Avian Pox has been observed on Rossel Island only, and may pose a risk to this species if it spreads (W. Goulding in litt. 2016). This species also exhibits high prevalence of avian haemosporidian parasites (Goulding et al. 2016b).

Conservation actions

Conservation Actions Underway
There is a colour -ringed population on Sabara and ongoing studies of the species on Tagula, Junet and Panawina (W. Goulding in litt. 2016).

Conservation Actions Proposed
Continue surveying  suitable habitat on Tagula. Improve understanding of its ecological requirements, tolerance of habitat degradation and threats. Improve knowledge of its demography. 

Acknowledgements

Text account compilers
Derhé, M., Dutson, G. & Symes, A.

Contributors
Burrows, I. & Goulding, W.


Recommended citation
BirdLife International (2019) Species factsheet: Cracticus louisiadensis. Downloaded from http://www.birdlife.org on 26/04/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/04/2019.