Data Zone
Justification of Red List category
This species has a small and declining population owing to losses of mature old-growth forest through continuing logging and forest conversion. Given that the population size of the largest subpopulation is likely to number less than 1,500, the species is assessed as Near Threatened.
Population justification
It has been described as fairly common in suitable habitat, but is likely to be rarer than commonly reported because it is often misidentified and occurs at low population densities (G. Dutson pers. obs. 2000, Watling 2000). Recent surveys have generated more data on this species, showing it to be widespread but at low population densities: approximately 1 bird/km2 on average, mostly calling males. There are a number of likely errors in this estimate, especially the number of silent birds overlooked. It is fairly common at the Garrick and Tomaniivi reserves; one or two can be heard most days in the central hills from Nausori Highlands to Nadrau and Monosavu. The species was recorded at 55% of the sites surveyed (19/34 sites) which were pre-selected to be the densest wettest old-growth forest. Very few were recorded in logged or degraded forest. If assumed to occur in 20% of the forest within its range (much of which is unsuitable), the total population is likely to number c.2,000-2,600 mature individuals with c.1,200-1,600 in the largest subpopulation on Viti Levu.
Trend justification
Remote sensing data (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein) indicate that in the three generations to 2021, forest loss in this species' range has been equivalent to c.2-3%, and this may accelerate to an equivalent rate of c.5-6% based on steeper declines recorded in 2021. Given the species' intolerance of habitat degradation, it is likely to be declining at least at the same rate as forest loss and degradation.
This species is found on Viti Levu, Vanua Levu, Taveuni, Kadavu and Ovalau in Fiji (Pratt et al. 1987). There are very few recent records from Vanua Levu, Taveuni, Kadavu or Ovalau.
It occurs up to 1,200 m in dense, mature, wet forests (Pratt et al. 1987). It has also been reported from mangroves and dense bush (Clunie 1984), however, it appears to be absent from extensive areas of degraded forest without scattered remnants of old-growth forest, and has a patchy distribution, probably being more common in mountains (G. Dutson pers. obs. 2000, D. Watling verbally 2000, G. Dutson in litt. 2005).
The main threat is the continuing habitat loss and deterioration from logging and mahogany plantations, with only c.50% of Viti Levu and Vanua Levu remaining forested (Watling 2000). However, according to the Department of Forestry, the logging rate is slowing, and there is only one active logging operation on Vanua Levu (V. Masibalavu in litt. 2007). Remote sensing data (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein) indicate that in the three generations to 2021, forest loss in this species' range has been equivalent to c.2-3%, and this may accelerate to an equivalent rate of c. 5-6% based on steeper declines recorded in 2021. Government priorities regarding Protected Areas in Fiji are undefined and so these areas are under threat, for example in the Sovi Basin Protected Area where the possibility of mining in the area is being explored (V. Masibalavu in litt. 2012). Invasive alien plant species, feral animals and species including Common Myna Acridotheres tristis and Red-vented Bulbul Pycnonotus cafer may also threaten the species (Gregory 2006).
Conservation and Research Actions Underway
It is protected by law and is recorded from several protected areas including Tomaniivi and Ravilevu Nature Reserves, the Sovi Basin and the Garrick Memorial Park (D. Watling in litt. 2000, V. Masibalavu in litt. 2007). BirdLife Fiji is working towards establishing three new PAs (Natewa Peninsula and two sites in Kadavu) with an effective monitoring framework (V. Masibalavu in litt. 2007).
Conservation and Research Actions Proposed
Develop a monitoring programme for forest birds as declines in population and the initiation of threat processes could well be going unnoticed (SPREP 2000). Develop in-country training in survey techniques (SPREP 2000). Survey populations on all five islands. Determine population densities in various forest habitats and altitudes. Monitor populations at well-known sites, e.g. Nausori Highlands. Advocate creation of community-based forest conservation reserves. Initiate management in gazetted nature reserves (D. Watling in litt. 2000).
21 cm. A heavy greyish-brown forest bird. Bllack head and throat of adult male contrasts strongly with grey-white ear-coverts, otherwise, uniform grey-brown plumage. Female and immature more consistently brownish and lack head pattern. Heavy, black bill with horn edgings and tip. Similar spp. Female only safely distinguished from slightly smaller Fiji Shrikebill C. vitiensis by bill size and shape or by presence of male. Females can also be confused with Wattled Honeyeater Foulehaio carunculata (which should be readily distinguished by voice, curved beak and yellow wattle) and female Golden Whistler Pachycephala pectoralis (which has rounder head and flatter bill). Voice Both species of shrikebill have drawn-out, wavering, whistling call with several variations. These are not distinguishable except with considerable experience.
Text account compilers
Vine, J.
Contributors
Dutson, G., Masibalavu, V. & Watling, D.
Recommended citation
BirdLife International (2024) Species factsheet: Black-throated Shrikebill Clytorhynchus nigrogularis. Downloaded from
https://datazone.birdlife.org/species/factsheet/black-throated-shrikebill-clytorhynchus-nigrogularis 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.