Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
Critically Endangered | Endangered | Vulnerable |
---|---|---|
- | C2a(i) | C2a(i); D1 |
Year | Category | Criteria |
---|---|---|
2021 | Near Threatened | C2a(i); D1 |
2016 | Endangered | C2a(i) |
2012 | Endangered | C2a(i) |
2008 | Endangered | C2a(i) |
2004 | Endangered | |
2000 | Endangered | |
1996 | Vulnerable | |
1994 | Vulnerable | |
1988 | Threatened |
Migratory status | not a migrant | Forest dependency | High |
Land mass type |
Land-mass type - continent |
Average mass | - |
Estimate | Data quality | |
---|---|---|
Extent of Occurrence breeding/resident (km2) | 51,900 | medium |
Number of locations | - | |
Severely Fragmented | - |
Value | Data quality | Derivation | Year of estimate | |
---|---|---|---|---|
No. of mature individuals | 600-1700 | poor | inferred | 2000 |
Population trend | Decreasing | medium | inferred | - |
Decline (3 years/1 generation past) | - | - | - | |
Decline (5 years/1 generation past) | - | - | - | |
Decline (10 years/1 generation past) | - | - | - | |
Decline (10 years/3 generation future) | 1-15 | - | - | - |
Decline (10 years/3 generation past and future) | 1-15 | - | - | - |
Number of subpopulations | 2-3 | - | - | - |
Percentage in largest subpopulation | 1-89 | - | - | - |
Generation length (yrs) | 3.6 | - | - | - |
Population justification: The total population has been guessed to number over 1,000 individuals (Seddon et al. 1999), and possibly over 2,500 individuals, but not more than 5,000 (L. Hansen in litt. 2016). The population in the Udzungwas alone might number 1,000-2,000 individuals (L. Hansen in litt. 2007), although it has also been guessed at 'some hundred' (Dinesen et al. 2001). Therefore, the population is conservatively placed in the range of 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 is roughly equivalent to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.
Trend justification: This species is inferred to be declining due to ongoing forest loss (Global Forest Watch 2021). The forest is being cleared, altered and fragmented for agriculture, plantations and timber extraction (Svendsen and Hansen 1995; Cordeiro 1998).
Between 2000-2019, this species experienced forest cover loss of 8.1% (Global Forest Watch 2021). This species has a high forest dependency and assuming that the population declines at a similar rate, this would equate to a rate of decline of c.5% over the past 3 generations. Green et al. (2013) estimated that the entire Eastern Arc mountain range lost 26% of forests between 1975-2000, which would equate to a decline rate of 11% over 3 generations. Between 2016-2019, this species's experienced a loss of forest cover of 3% (Global Forest Watch 2021). Projected forward over 3 generations, this would equate to a loss of 8%. The overall population decline is suspected to fall into the band 1-15%.
Country/Territory | Occurrence status | Presence | Resident | Breeding | Non-breeding | Passage |
---|---|---|---|---|---|---|
Tanzania | N | Extant | Yes |
Country/Territory | IBA Name |
---|---|
Tanzania | Udzungwa National Park |
Tanzania | Rubeho Mountains |
Tanzania | Udzungwa Mountains |
Tanzania | Uluguru Mountains |
Tanzania | East Usambara Mountains |
Tanzania | West Usambara Mountains |
Tanzania | Udzungwa Mountain Range |
Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
---|---|---|---|
Forest | Subtropical/Tropical Moist Montane | major | resident |
Altitude | 900 - 1850 m | Occasional altitudinal limits | (max) 2200 m |
Threat (level 1) | Threat (level 2) | Impact and Stresses | |||||||
---|---|---|---|---|---|---|---|---|---|
Agriculture & aquaculture | Annual & perennial non-timber crops - Small-holder farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
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Agriculture & aquaculture | Wood & pulp plantations - Scale Unknown/Unrecorded | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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Biological resource use | Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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Climate change & severe weather | Habitat shifting & alteration | Timing | Scope | Severity | Impact | ||||
Future | Whole (>90%) | Unknown | Unknown | ||||||
|
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Human intrusions & disturbance | Recreational activities | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Negligible declines | Low Impact: 5 | ||||||
|
Purpose | Primary form used | Life stage used | Source | Scale | Level | Timing |
---|---|---|---|---|---|---|
Pets/display animals, horticulture | - | - | International | Non-trivial | Recent |
Recommended citation
BirdLife International (2023) Species factsheet: Ploceus nicolli. Downloaded from
http://www.birdlife.org on 02/02/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 02/02/2023.