VU
Baudo Oropendola Psarocolius cassini



Justification

Justification of Red List Category
This species has a small range, with recent records from only a few sites. The species is considered rare and local, and is thought to be very small in size. Habitat loss is continuing and posing a threat to the species. Consequently, this species is listed as Vulnerable.

Population justification
The species is considered rare and local, but it is also poorly known. The population is provisionally placed in the band 1,000-2,499 individuals. This number is confirmed by Renjifo et al. (2014), who report less than 2,500 individuals. This estimate roughly equates to 600-1,700 mature individuals.

Trend justification
The species is assumed to be in decline as a consequence of continuing habitat degradation within its small range, but the population trend has not been assessed directly. Tracewski et al. (2016) measured the forest loss within this species’s range between 2000 and 2012 as c. 57 km2. This roughly equates to a rate of forest loss of 1% over three generations (13.8 years) for this species, with the assumption that habitat loss has continued at the same rate to the present day. Even though Baudo Oropendola seems to be strictly forest-dependent (Fraga and Sharpe 2018), it is highly unlikely that the rate of population decline based on habitat loss alone exceeds 10% over three generations.

Distribution and population

Psarocolius cassini is endemic to the Chocó in north-west Colombia, where it occurs in the foothills and lowlands around the serranías de los Saltos and de Baudó. Until recently, the only sightings were from a nesting colony at the headwaters of the río Acandí in 1991 (Renjifo et al. 2002), and north of Ensenada de Utría National Park in 1997 and 1999, when two and six individuals respectively were seen (Strewe 1999). Later, two groups of 7-12 individuals were seen in the Siviru and Tipicay river basins, and 60 inactive nests documented (Fundación ProAves 2008). During an expedition to the Western Cordillera in 2010, 70-80 individuals in two groups were discovered at c.120 km from Ensenada de Utría National Park (Fraga and Sharpe 2018). The species's occurrence in the río Juradó valley has never been documented, and this area should not be considered a valid site of occurrence (Renjifo et al. 2002).

Ecology

This species depends on humid lowland forest. It occurs in both primary and secondary forests as well as along edges, between 100 and 365 m (Strewe 1999, Fraga and Sharpe 2018). It has been observed along rivers, and most recently on a sandy-soiled coastal plain (Strewe 1999). It may exhibit edaphic habitat specialisation and prefer primary forests with a naturally broken canopy, including very tall emergents in which feeding has been noted (Strewe 1999). Groups of 2-12 individuals forage for fruit and insects in the canopy (Strewe 1999, Fundación ProAves 2008). Two individuals seen in 1997 associated with a flock of c.25 Chestnut-headed Oropendola P. wagleri (Strewe 1999). The breeding season is probably May-June (Jaramillo and Burke 1999). Recently, 60 inactive nests were found between 19 and 20 metres above the ground in peach palms Bactris gasipaes and Guazuma ulmifolia trees, located in a transitional habitat between mature forest and banana plantations, on the banks of the Tripicay river (Fundación ProAves 2008).

Threats

The most pertinent threat is the destruction of forests. Particularly along rivers, forests are being cleared for agriculture, oil palm plantations, infrastructural development and commercial or small-scale logging (Strewe 1999). The development programmes for the Pacific region involve greatly expanding the road network, promoting human immigration and settlement, logging, agricultural expansion and mining (Dinerstein et al. 1995, Wege and Long 1995, WWF/IUCN 1994-1997, Strewe 1999). In the area north of Ensenada de Utría, a striking increase in logging (especially of large emergents), agricultural activity and road-building, notably the bridging of a large river, was noted between 1997 and 1999 (Strewe 1999). Plans to create an interoceanic canal and complete the Pan-American highway across the Darién Gap have been halted, but if re-started this would have a severe impact on forests and birds in the region (Dinerstein et al. 1995, Wege and Long 1995, WWF/IUCN 1994-1997). Importantly, the two recently discovered groups in the Western Cordillera are currently unprotected, while deforestation in the region is accelerating (Fraga and Sharpe 2018). Additionally, Baudo Oropendola is being trapped for food and for the cagebird trade (Fundación ProAves 2008).

Conservation actions

Conservation Actions Underway

Considered Endangered at the national level in Colombia (Renjifo et al. 2002, 2014). Ensenada de Utría Natural National Park protects at least one colony along R Boroboro (Hernández-Jaramillo and Calderón-Franco 2014), but the closed-canopy forest there may not be favoured by the species (Strewe 1999). It may also be found in the lower elevations of the Paramillo Natural National Park (Fraga and Sharpe 2016). A number of natural biotic areas/anthropogenic reserves are located within its range (IUCN 1992) and could contribute to its protection.

Conservation Actions Proposed

Conduct surveys to elucidate the distribution range. Research its ecology, especially aspects related to conservation, such as precise habitat requirements and tolerance of habitat degradation. Ensure effective protection of the currently known sites of occurrence. Advocate conservation measures within natural biotic areas/anthropogenic reserves.

Identification

46 cm. Large, black-and-chestnut, crow-like icterid. Black with rich chestnut back, flanks and closed wings (blackish primary tips only). Bare pink cheek patch. Lemon-yellow tail with blackish central tail-feathers. Long, black, conical bill, tipped orange-red. Similar species Black Oropendola P. guatimozinus only reliably distinguished by bare blue cheek patch, pink wattle and culmen base. Voice Two-part song. Series of bubbly, tinkling notes overlaid by metallic sounds followed by loud, liquid gurgle skol-l-l-l-l-wool. Nasal wak call.

Acknowledgements

Text account compilers
Hermes, C., Gilroy, J., Pople, R., Sharpe, C.J.

Contributors
Caro, D. & Downing, C.


Recommended citation
BirdLife International (2020) Species factsheet: Psarocolius cassini. Downloaded from http://www.birdlife.org on 18/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/09/2020.