||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.
||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.
||14 cm. Medium-sized, flycatcher-like warbler of forest and woodland. Glossy blue-black upperparts. Prominent white flash on wings. Orange throat and breast, fading to yellow on belly and vent. Voice Rarely calls (Evans 1997b): series of thin, squeaky notes. Hints Most recently seen in forest at Amani in East Usambara Mountains (Tanzania).
|Red List Category & Criteria:
||Butchart, S. & Taylor, J.
||Cordeiro, N., Hansen, L. & Stuart, S.
||Benstead, P., Ekstrom, J., Evans, M., Mahood, S., Shutes, S., Starkey, M. & Symes, A.
While there are still relatively few records of this species, it clearly has a very small and fragmented area of occupancy, within which it is rare. It appears largely restricted to lowland and foothill forest which is disappearing fast, and it is probably sensitive to alteration of its forest habitat. It is therefore considered Endangered.
|Previously published Red List assessments:|
- 2008 – Endangered (EN)
- 2004 – Endangered (EN)
- 2000 – Endangered (EN)
- 1994 – Not Recognized (NR)
- 1988 – Not Recognized (NR)
|Range Description:||Hyliota usambara is a little known and probably overlooked species of north-east Tanzania (Cambridge-Tanzania Rainforest Project 1994, Urban et al. 1997, Evans 1997b, Seddon et al. 1999b) recorded mainly from the foothills of the East Usambara Mountains, where it appears to be uncommon, and from a single sighting at Dindira in the West Usambaras (Urban et al. 1997, S. Stuart in litt. 2003) at 1,000 m. There is one other reference to a specimen taken between 1904 and 1907 along the Ruvu river, although this is now thought to refer to H. flavigaster (Sclater and Moreau 1933, Urban et al. 1997, L. Hansen in litt. 2006) but at present insufficient information is available to determine the exact localities or altitudes referred to. Given that there is only c.370 km2 of forest remaining in its stronghold of the East Usambaras, and that the species apparently occurs very patchily within forest, preferring the lowlands, both its Area of Occupancy and total population are probably very small. |
Tanzania, United Republic of
|♦ Estimated area of occupancy (AOO) - km2:||410||♦ Continuing decline in area of occupancy (AOO):||Yes|
|♦ Extreme fluctuations in area of occupancy (AOO):||No||♦ Estimated extent of occurrence (EOO) - km2:||7700|
|♦ Continuing decline in extent of occurrence (EOO):||Yes||♦ Extreme fluctuations in extent of occurrence (EOO):||No|
|♦ Number of Locations:||2-5||♦ Continuing decline in number of locations:||Unknown|
|♦ Extreme fluctuations in the number of locations:||No||♦ Lower elevation limit (metres):||300|
|♦ Upper elevation limit (metres):||1200|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The population is estimated to number 1,000-2,499 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.|
Trend Justification: The species is suspected to be declining at a moderate rate, owing to small-scale logging and clearance for agriculture.
|Current Population Trend:||Decreasing|
|♦ Number of mature individuals:||600-1700||♦ Continuing decline of mature individuals:||Yes|
|♦ Extreme fluctuations:||No||♦ Population severely fragmented:||Yes|
|♦ No. of subpopulations:||2-100||♦ Continuing decline in subpopulations:||Unknown|
|♦ Extreme fluctuations in subpopulations:||No||♦ All individuals in one subpopulation:||No|