Chaetocercus bombus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Caprimulgiformes Trochilidae

Scientific Name: Chaetocercus bombus Gould, 1871
Common Name(s):
English Little Woodstar
Spanish Colibrí Abejorro, Estrellita Chica
Acestrura bombus (Gould, 1871) — BirdLife International (2000)
Acestrura bombus (Gould, 1871) — BirdLife International (2004)
Acestrura bombus (Gould, 1871) — Collar and Andrew (1988)
Acestrura bombus (Gould, 1871) — Collar et al. (1994)
Acestrura bombus (Gould, 1871) — Sibley and Monroe (1990, 1993)
Acestrura bombus (Gould, 1871) — Stotz et al. (1996)
Taxonomic Source(s): SACC. 2005 and updates. A classification of the bird species of South America. Available at: #
Identification information: 6-7 cm. Tiny hummingbird with typical woodstar plumage pattern. Male has dark bronzy blue-green upperparts and belly. Buffy pectoral-band and postocular line meet. Rosy gorget. Forked tail. Female has similarly coloured upperparts, but underparts are cinnamon, with tawny sides and vent, and rounded tail has black subterminal bar. Immature like female. Both sexes have a straight black bill. Similar spp. Most other male woodstars have white pectoral-band and postocular line. Voice a series of rapid chit-cheet and chit-chit-cheet calls.

Assessment Information [top]

Red List Category & Criteria: Vulnerable C2a(i) ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Freile, J. & Marks, T.
Facilitator/Compiler(s): Benstead, P., Harding, M., Isherwood, I., Pilgrim, J., Sharpe, C.J., Stuart, T., Symes, A.
This species has a large range, but it is severely fragmented, and only a fraction is likely to be occupied. It qualifies as Vulnerable because the dearth of recent records suggests that the population may now be small, comprised of very small subpopulations, and declining significantly owing to rapid rates of deforestation.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Chaetocercus bombus has historically been recorded from central Peru (seven departments from La Libertad and Huánaco in the south), on both slopes of the Andes north through Andean and west-central lowland Ecuador (14 provinces) to south-west Colombia (Nariño), where it was recently discovered and is thought to be seasonal (Salaman and Mazariegos 1998). It was once common, but has declined significantly, and very few were recorded in late 20th century (Fjeldså and Krabbe 1990). During the 1990s, it was considered uncommon in Machalilla National Park, Manabí, Ecuador (Parker and Carr 1992), and common in the newly established Loma Alta Ecological Reserve (7.5 km2), Guayas, Ecuador (Becker and López Lanús 1997), but recent reports relate to single individuals (e.g. at least one at Dos Mangas Communal Reserve, Guayas in 2005 [Ágreda 2007]) and it is not known to be present regularly or in large numbers anywhere in the country (Gurney 2006, Athanas and Greenfield 2016). There are an increasing number of  recent reports from northern Peru (T. Marks in litt. 2003, Angulo et al. 2012).

Countries occurrence:
Colombia; Ecuador; Peru
Additional data:
Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:359000
Continuing decline in extent of occurrence (EOO):YesExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:11-100Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:No
Upper elevation limit (metres):3050
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The population is estimated to number 2,500-9,999 mature 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 3,750-14,999 individuals, rounded here to 3,500-15,000 individuals.

Trend Justification:  A moderate and on-going population decline is suspected on the basis of continuing losses and fragmentation of the species's preferred habitat.
Current Population Trend:Decreasing
Additional data:
Number of mature individuals:2500-9999Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:Yes
No. of subpopulations:2-100Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:It is found between sea-level and 3,050 m, in humid evergreen forest and, more commonly, in the transitional zone between dry and wet forests. It appears to make seasonal or occasional movements, perhaps in response to continental rainfall patterns or El Niño Southern Oscillation events (Salaman and Mazariegos 1998).

Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):4.2
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): Below 900 m, the rate of deforestation in western Ecuador over the period 1958-1988 was 57% per decade (Dodson and Gentry 1991). High levels of habitat loss are continuing, at least in unprotected areas, and will soon remove almost all remaining lowland forest if effective action is not taken urgently. In higher parts of the species's range, rates of habitat destruction are not as great, but logging and conversion of land for agriculture and plantations are causing loss and degradation of forest (Dodson and Gentry 1991, Dinerstein et al. 1995).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
CITES Appendix II. It occurs in Río Ñambí Community Nature Reserve (Nariño), Río Palenque Reserve (Pichincha), Loma Alta Ecological Reserve, Podocarpus National Park (J. F. Freile in litt. 2000) and Machalilla National Park, in Ecuador and Laquipampa Wildlife Refuge (Lambayeque), in Peru (Angulo et al. 2012). Machalilla is the largest of the five, but lacks effective protection.

Conservation Actions Proposed
Search for the species, especially in parts of its range where habitat remains but where there are few recent records (Peru, central Ecuador, east Andean slopes throughout).

Citation: BirdLife International. 2016. Chaetocercus bombus. The IUCN Red List of Threatened Species 2016: e.T22688257A93189584. . Downloaded on 18 June 2018.
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