Justification of Red List Category
This species is considered Endangered because it has a very small population, which is feared to be declining due to the degradation and loss of its habitat. In this context, the species's rarity indicates that the population may well be comprised of extremely small subpopulations. The species is however tolerant of some degree of habitat modification; if declines are found to be less severe than thought, the species may be downlisted.
The population size appears to be genuinely small (F. Angulo in litt. 2020). The population is estimated to number 250-999 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 375-1,499 individuals in total, rounded here to 350-1,500 individuals.
This species appears to have been lost from parts of its former range and is feared to be declining slowly, owing to habitat degradation and fires. The species's apparent rarity, occurrence in remote areas and low detectability, together with its tolerance of some degree of habitat modification, suggest that declines may be smaller than feared (F. Angulo in litt. 2020, S. Cuadros in litt. 2020).
Taphrolesbia griseiventris occurs in the Andes of north-central Peru, where it is known from nine localities, on the Pacific slope in Cajamarca, in the río Marañón drainage in Cajamarca and Huánuco, and in the Huascaran National Park in Ancash. There have been very few records since 1950: in Cajamarca, two males where the main road from Cajamarca to the coast crosses to the Pacific slope, in the early 1990s (B. P. Walker in litt. 1997); a female feeding nestlings in February 1999, near the río Chonta, south-east of Cajamarca (Garrigues 2001); a female nest-building above Sucre, south-west of Celendín in February 1999 (Garrigues 2001); in Huánuco, near Cullcui in 1983 (where it was also recorded in 1922) (T. S. Schulenberg in litt. 1994); three or more seen at the bridge where the Huánuco-La Unión road crosses the río Marañón, in 1975 (but not subsequently, despite several searches) (J. P. O'Neill in litt. 1997, W-P. Vellinga in litt. 1997) and three nests near Cajamarca in February 2001, two again occupied in December 2001 (J. Flanagan in litt. 2002). It was been reported in 2006 from Marcabalito, La Libertad (R. Zeppilli per F. Angulo in litt. 2012), and has been seen close to Llanganuco lake, Ancash (Angulo in litt. 2012). Two collecting localities near Cajamarca and one near Cajabamba have produced the greatest number of specimens, but the species has not been seen at any of these sites recently.
It occurs in semi-arid country, rocky areas and deep canyons mainly at elevations of 2,750-3,850 m (Schulenberg et al. 2007, F. Angulo in litt. 2012, S. Cuadros in litt. 2020). In less disturbed areas, it apparently inhabits steep, dry slopes with cacti, agaves, bromeliads, shrubs and other xerophytic plants, and is normally recorded near streams and running water (Garrigues 2001, F. Angulo in litt. 2020). The species appears to tolerate habitat modification; however, it is not known whether it can complete its life-cycle or occur at normal densities in heavily cultivated areas. (F. Angulo in litt. 2020, S. Cuadros in litt. 2020). It has been observed in areas described as partly cultivated, through to heavily cultivated land with many Eucalyptus trees (B. P. Walker in litt. 1997, S. Cuadros in litt. 2020), and it appears to be dominant over all other hummingbirds at flowering woody shrubs and trees (H. Lloyd in litt. 2007). The species is nectarivorous, preferably feeding on flowers of Delostoma integrifolium (Cuadros 2019). Two nests (one in construction) were found in February 1999, each concealed in the overhang of road cuttings (Garrigues 2001). Of three nests found in February 2001, two were used twice within the same year: in December 2001 one had two young, and the other had a female apparently incubating eggs (J. Flanagan in litt. 2002).
The species is mainly threatened by the burning of its habitat (especially shrubby areas to stimulate regeneration of pastures) (Flanagan 2019). Agriculture and livestock raising represent a threat in parts of its range, but the species seems to tolerate some degree of disturbance (F. Angulo in litt. 2020, S. Cuadros in litt. 2020). There are plans to construct a damn at rio Chonta, which would probably destroy the species's habitat there (F. Angulo in litt. 2012, S. Cuadros in litt. 2020).
Conservation Actions Underway
CITES Appendix II, but no other measures are known. It occurs in Huascarán National Park (F. Angulo in litt. 2012). A new protected area for the species has been proposed (Angulo et al. 2008).
14-17 cm. Large, fork-tailed hummingbird. Bronzy-green upperparts with white postocular spot. Deeply forked, long green tail has golden-orange tips. Underparts entirely grey, with blue throat (lacking in female, which also has shorter, less forked tail). Similar spp. Unmistakable within range.
Text account compilers
Angulo Pratolongo, F., Benstead, P., Cuadros, S., Flanagan, J., Isherwood, I., Lloyd, H., O'Neill, J., Schulenberg, T., Sharpe, C.J., Stuart, T., Symes, A., Vellinga, W.-P., Walker, B.P. & Züchner, T.
BirdLife International (2021) Species factsheet: Taphrolesbia griseiventris. Downloaded from http://www.birdlife.org on 16/01/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/01/2021.