Species

Justification
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Taxonomic source(s)
Erard, C.; Fry, C. H.; Grimes, L. G.; Irwin, M. P. S.; Keith, S.; Lack, P. C.; Pearson, D. J.; Tye, A. 1997. Sylviidae, Old World warblers. In: Urban, E.K.; Fry, C.H.; Keith, S. (ed.), The birds of Africa v. 5, pp. 57-431. Academic Press, San Diego, London: Academic Press.

Taxonomic note
Hyliota australis (Sibley and Monroe 1990, 1993) has been split into H. australis and H. usambara following Erard et al. (1997), largely on the basis of it sexual monomorphism in H. usambara (actually a mistaken judgement). However, examination of museum material indicates that, compared with australis, usambarae is considerably smaller, with wholly (vs partly) black thighs, female upperparts steely blue-black (vs dull sooty-black), female underparts, lores, frons and ear-coverts rich tawny (vs pale creamy-yellow below, with lores, frons and ear-coverts concolorous with rest of upperparts). These differences are sufficient for usambarae to achieve species status.

Population justification
The global population size has not been quantified, but the species is described as scarce to uncommon (del Hoyo et al. 2006).

Trend justification
The population is suspected to be in decline owing to ongoing habitat destruction.

Further web sources of information
View photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Butchart, S., Ekstrom, J.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2013) Species factsheet: Hyliota australis. Downloaded from http://www.birdlife.org on 24/05/2013. Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/05/2013.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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