LC
Viridian Dacnis Dacnis viguieri



Justification

Justification of Red List Category
Although this species may have a restricted range, it is not believed to approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km² combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern.

Population justification
The species’s population size has not previously been estimated and no survey data are available, but it has been described as ‘rare’. Based on the estimated area of forest with at least 30% canopy cover in the species’s mapped range in 2018 (14,000 km2), the recorded population densities of a closely-related species with a similar ecology (Dacnis cayana: 0.7 individuals/km2 in lowland rainforest in southern Guyana [Thiollay 1986], 12 individuals/km2 in rainforest in Peru [Munn 1995]), and assuming that 22-45% of suitable habitat is occupied, the species’s population size is suspected to fall within the range 4,412 – 75,636 individuals, roughly equivalent to 2,941-50,424 mature individuals. Whilst the species is described as rare, the species has been recorded over a wide area and it could be fairly cryptic and overlooked. Additionally, the lower bound of habitat occupancy (22% of forest within its range) could be unduly conservative, given that large parts of the species’s range contain reasonably intact forest. It is therefore considered unlikely that the true population size falls below or approaches the threshold of 10,000 mature individuals, so it is here placed in the band 10,000-19,999 mature individuals.

Trend justification
Data on trends are lacking, but slow to moderate declines are likely to be occurring, owing to habitat loss within parts of the range. An analysis of forest loss from 2000 to 2012 found that forest within the species’s range was lost at a rate equivalent to 2% over three generation lengths (Tracewski et al. 2016). Assuming the population has declined at the same rate as the forest cover, the species is suspected to have undergone a reduction of 2% over the past three generation lengths, and assuming that forest loss continues at a similar rate, the population may be assumed to continue to decline at this rate in future.

Distribution and population

Dacnis viguieri occurs in north-west Colombia (north Chocó, north-west Antioquia, south-west Córdoba) and east Panama (east Darién) (Hilty and Brown 1986, Ridgely and Gywnne 1989, Ridgely and Tudor 1989). Within this small range it is generally rare. The species is known from 44 specimens in Colombia, with all but four collected at Jurado, Chocó, on the Pacific coast at the base of Serranía de los Saltos (Fundación ProAves 2011). A recent record from Panama comes from Cana, at the foothills of Cerro Pirre, thus the species probably also occurs on the Colombian side of Cerro Tacarcuna (Fundación ProAves 2011).

Ecology

Although primarily a humid forest species, D. viguieri uses edge habitat and has been recorded in scrub (Hilty and Brown 1986, Isler and Isler 1987). It has been recorded most often in foothills up to 700 m, where it may be more numerous than in the flat coastal lowlands (Hilty and Brown 1986, Ridgely and Tudor 1989).

Threats

In the Urabá lowlands and the Sinú valley, most habitat has been converted to banana plantations and cattle ranches (P. G. W. Salaman in litt. 1999, Fundación ProAves 2011), and more recently palm oil plantations. This agricultural expansion has cleared the lowlands almost entirely and is encroaching on the foothills of the Western Andes and Serranía de Darien. In Panama, deforestation is on-going near El Real and is likely to be taking place in the Jaque valley (G. R. Angehr in litt. 2011). Some extensive, largely intact forests remain in Panama and Chocó, but these would be threatened by the completion of the Pan-American highway through Daríen (Wege 1996).

Conservation actions

Conservation Actions Underway

No targeted action is known.

Conservation Actions Proposed

Survey all known and historical sites to determine current range and estimate rates of contraction and population decline. Conduct ecological studies to identify habitat associations and assess levels of tolerance of habitat disturbance. Protect areas of suitable habitat and safeguard against clearance.

Acknowledgements

Text account compilers
Sharpe, C.J., Wheatley, H., O'Brien, A., Gilroy, J., Taylor, J., Smith, D.

Contributors
Angehr, G. & Salaman, P.G.W.


Recommended citation
BirdLife International (2022) Species factsheet: Dacnis viguieri. Downloaded from http://www.birdlife.org on 05/12/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 05/12/2022.