Data Zone
Justification of Red List category
This species has a very small range and occurs at only few localities. Significant areas of habitat remain, but it is presumably declining in response to changing agricultural practices and conversion of habitat. The remaining population is estimated to be very small and divided into small subpopulations. The species is therefore listed as Endangered.
Population justification
Based on the area of the species’s mapped range (916 km2), the recorded population densities of congeneric species (Diglossa albilatera and Diglossopis cyanea: a minimum of 10 individuals/km2 in montane forest in Ecuador; Diglossa humeralis: 20-40 individuals/km2 in secondary scrub/farmland in Ecuador [Cresswell et al. 1999]), and assuming that 11-45% of the range is occupied, the species’s population size is estimated to fall within the range 1,000 – 16,500 individuals, roughly equivalent to 670 – 11,000 mature individuals.
Trend justification
A comparison of historical collection data with that obtained over the past few decades suggests that the population is decreasing (Sharpe 2008, 2015).
Diglossa venezuelensis is restricted to two mountainous areas in north-east Venezuela: the Turimiquire Massif (both the Serranía de Turimiquire west of the San Antonio valley, and the Cordillera de Caripe to the east) on the borders of Anzoátegui, Monagas and Sucre, and the westernmost Paria Peninsula, Sucre. Collections from the 1920s and 1930s suggest that it was once not uncommon, but there have been relatively few records since. Systematic surveys on Cerro Humo in 1990-1991 (C. J. Sharpe in litt. 1992) and 1994 (Evans et al. 1994) failed to find the species (Sharpe 2015), although it has been seen on Cerro Humo sporadically since then (C. J. Sharpe in litt. 2011); it has not been recorded elsewhere on the peninsula, despite significant effort (C. J. Sharpe in litt. 2015). Searches in the Cordillera de Caripe during the 1990s also proved fruitless (Colvee 1999). Since then it has only been recorded on five mountains: Cerros El Guamal and Quiriquire (Piedra 'e Mole') in the in the Serranía de Turimiquire (Azpúrua 2007), Cerro Negro and Cumbres de San Bonifacio in the Cordillera de Caripe (Boesman and Curson 1995, Azpúrua 2007) and Cerro de Humo on the Paria Peninsula (C. J. Sharpe in litt. 2011). Recent sightings (post-2000), involving only a handful of birds, come from only three localities: Quiriquire (Piedra 'e Mole'), Cerro Negro and Cerro Humo (Sharpe 2015, C. J. Sharpe in litt. 2015).
It inhabits montane, evergreen forest edge, secondary forest and second growth scrub (Boesman and Curson 1995), at elevations of 1,525-2,450 m on the Cordillera de Caripe, and c.885 m on the Paria Peninsula. It may have specialised habitat requirements, associating with the ecotone between Clusia-dominated forest and herbaceous vegetation, which would explain its apparently restricted distribution on Cerro Negro. It may undertake some seasonal movements (J. Pérez-Emán in litt. 2012, Hilty and Sharpe 2015).
The species is threatened by habitat clearance for agriculture and livestock (Sharpe 2015). There has been widespread clearance for agriculture and pasture in the Cordillera de Caripe, resulting in extensive degradation of forest. Even in El Guácharo National Park there is clearance, repeated burning and understorey removal for coffee (Boesman and Curson 1995). The slopes of Cerro Negro are largely bare, with the more obvious forest patches actually shade-coffee plantations (Boesman and Curson 1995). There is conversion to coffee, mango, banana and citrus plantations in the Turimiquire Massif, but extensive forest areas remain (Colvee 1999, C. J. Sharpe in litt. 2011, Sharpe 2015). On Cerro Humo, increases in cash-crop agriculture since the mid- to late 1980s has resulted in uncontrolled burning and forest degradation. A proposed gas pipeline on the Paria Peninsula could have disastrous consequences for the species's habitat (C. J. Sharpe in litt. 2003). A new paved road from Güiria to Macuro will almost certainly lead to increased habitat clearance (C. J. Sharpe in litt. 2003). In 2012, the state oil company PDVSA began preparations to construct antennas, a radar, and a heliport on the summit of Cerro Patao (the second highest summit of the Paria Peninsula), where a patch of 0.1 km2 of cloud forest remains (M. Santos in litt. 2012). By 2012, the number of park personnel in the Paria Peninsula National Park had fallen to two (M. Santos in litt. 2012).
Conservation Actions Underway
It is considered nationally Endangered in Venezuela (Sharpe 2008, 2015). It is formally protected by Paria Peninsula and El Guácharo National Parks; neither park is adequately resourced and both are subject to deforestation for agriculture and hunting. The latter was expanded to include a further 500 km2 of largely undisturbed forest (Gabaldón 1992). A programme of research into basic ecology and conservation needs is being carried out at the Central University of Venezuela (C. J. Sharpe in litt. 2011).
13.5 cm. Dull black flowerpiercer. Male black with small white tuft on flanks. Female olive-brown above with yellowish-olive head and buffy-brown below. Upcurved, hook-tipped bill. Similar spp. Only sympatric Diglossa is Rusty Flowerpiercer D. sittoides. Female similar, but smaller and lacks white on flanks.
Text account compilers
Pople, R., Sharpe, C.J., Symes, A., Capper, D., Wheatley, H.
Contributors
Pérez-Emán, J., Santos, M. & Sharpe, C J
Recommended citation
BirdLife International (2024) Species factsheet: Venezuelan Flowerpiercer Diglossa venezuelensis. Downloaded from
https://datazone.birdlife.org/species/factsheet/venezuelan-flowerpiercer-diglossa-venezuelensis on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/11/2024.