Justification of Red List Category
Although previously treated as Critical, a recent re-evaluation of poorly known, possibly extinct Critical species and Data Deficient species has indicated that this taxon is best treated as Data Deficient at present.
This species is only known from its type specimen and as such no population estimates are available.
There are no data on overall population size, trends or threats.
Heliangelus zusii is known from a single trade-skin purchased in 1909 in Bogotá, and speculated to have been collected on the East Andes or possibly the Central Andes of Colombia, within a few hundred kilometres of the capital. However, some Bogotá specimens came from as far away as Ecuador (F. G. Stiles in litt. 1999), and a recent reassessment (Kirchman et al. 2009) suggests that the species might have originated in humid or semi-arid habitat anywhere from northwestern Venezuela to northern Peru up to 3,200 m. Since no other specimen is known, it is assumed to be (or have been) a species of restricted range. Much habitat in the Colombian East and Central Andes has been extensively degraded, particularly within the lower limits of this species's presumed elevational range. However, its probable habitat preferences suggest that it is not inconceivable that a remnant population may persist. The validity of this taxon is sometimes questioned (e.g. F. G. Stiles in litt. 1999), but DNA sequencing supports its recognition as a valid taxon (Kirchman et al. 2009).
Heliangelus spp. typically occur in cloud-forest and shrubbery at elevations of 1,200-3,400 m, mostly at 1,400-2,200 m. This species is probably more closely allied to Aglaiocercus and Taphrolesbia, and should be sought in humid or semi-arid habitat as high as 3,200 m from northwestern Venezuela to northern Peru (Kirchman et al. 2009).
Much habitat in the Colombian East and Central Andes has been extensively degraded, particularly within the lower limits of this species's presumed elevational range. However, its probable habitat preferences suggest that it is not inconceivable that a remnant population may persist.
Conservation Actions Underway
CITES Appendix II. Considered Data Deficient in Colombia (Renjifo et al. 2002). No conservation measures known.
12 cm. Dark bluish-black hummingbird with deeply forked tail. Single male (?) specimen dark bluish-black body. Brilliant green frontlet and gorget. Deep greenish-blue lower back and rump. Deeply forked, glittering, dark purple tail. Short, straight, black bill. Similar spp. Previously assigned to Nehrkorn's Sylph Neolesbia nehrkorni (three specimens considered hybrids) which has bluish-black (not purple) tail, slightly decurved (not straight) bill, and no gorget or frontlet. Other Heliangelus have green or bronzy-green body plumage. Voice Unknown.
Text account compilers
Benstead, P., Butchart, S., Capper, D., Isherwood, I., Sharpe, C J, Symes, A.
Stiles, F. & Cortes, O.
BirdLife International (2019) Species factsheet: Heliangelus zusii. Downloaded from http://www.birdlife.org on 17/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/11/2019.