|Red List Category & Criteria:
||Taylor, J. & Butchart, S.
||Baker, N., Dinesen, L., Hansen, L. & Moyer, D.
||Ekstrom, J., Evans, M., Shutes, S., Starkey, M., Symes, A., Taylor, J.
This species occurs at low densities and is assumed to have a very small, declining and severely fragmented population, with each subpopulation being extremely small. In the light of these factors this species is listed as Endangered.
|Previously published Red List assessments:|
- 2008 – Endangered (EN) –
- 2004 – Endangered (EN) –
- 2000 – Endangered (EN) –
- 1996 – Vulnerable (VU) –
- 1994 – Vulnerable (VU) –
- 1988 – Threatened (T) –
|Range Description:||Ploceus nicolli occurs at low densities in the East and West Usambara, Uluguru and Udzungwa Mountains in Tanzania. In the West Usambaras, the nominate subspecies occurs in small numbers at Shume, Magamba and Mazumbai (N. Baker in litt. 1999). In the East Usambaras, it is fairly common at two sites within the Nilo Forest Reserve (Cordeiro 1998, Seddon et al. 1999b) - probably the subspecies's last remaining stronghold (Seddon et al. 1999b). P. n. anderseni is found in the Uluguru Mountains (three records, all from Uluguru North Forest Reserve (Svendsen and Hansen 1995), but not recorded during surveys in 1999-2001 [Burgess et al. 2002]) and the Udzungwa Mountains, including Udzungwa National Park, Ndundulu Forest and the Nyumbanitu Mountains, as well as in a tiny patch of forest c.95 km east of Iringa and in the Udzungwa Scarp Forest Reserve (D. Moyer in litt. 1999). There is a possible record from the Rubeho Mountains, but this has not been confirmed (Fjeldså et al. 1997). The total population has been guessed to number over 1,000 individuals (Seddon et al. 1999b). However, the population in the Udzungwas alone might number 1,000-2,000 individuals (L. Hansen in litt. 2007), although it has been conservatively guessed at 'some hundred' (Dinesen et al. 2001). |
Tanzania, United Republic of
|♦ Continuing decline in area of occupancy (AOO):||Yes|
|♦ Extreme fluctuations in area of occupancy (AOO):||No||♦ Estimated extent of occurrence (EOO) - km2:||7900|
|♦ Continuing decline in extent of occurrence (EOO):||Unknown||♦ Extreme fluctuations in extent of occurrence (EOO):||No|
|♦ Number of Locations:||11-100||♦ Continuing decline in number of locations:||Unknown|
|♦ Extreme fluctuations in the number of locations:||No||♦ Lower elevation limit (metres):||900|
|♦ Upper elevation limit (metres):||1850|
|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's forest habitat is being cleared, altered and fragmented for agriculture, plantations and timber extraction (Svendsen and Hansen 1995; Cordeiro 1998), thus the population is suspected to be in decline at an unknown rate.
|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|