Archived 2015 topics: Northern Screamer (Chauna chavaria): request for information

This discussion was first published as part of the 2012 Red List update, but remains open for comment to enable reassessment in 2015.

BirdLife species factsheet for Northern Screamer

Northern Screamer Chauna chavaria is endemic to the marshlands of northern Colombia and north-western Venezuela. It is currently listed as Near Threatened under criterion C2a(i) on the basis that its global population is thought to number fewer than 10,000 individuals and suspected to be declining as a result of hunting and habitat conversion; however, so far there has been insufficient information available on its sub-population structure for it to qualify as Vulnerable. It is listed as Vulnerable at the national level in the two countries in which it occurs, and may qualify as globally threatened. To confirm whether this is the case, more information is required, particularly on its status in Colombia, where the majority of the world population is found.

The Colombian sub-populations are variously calculated to amount to between 2,000 and 10,000 birds (Renjifo et al. 2002), with most recent estimates suggesting at least 5,000 (P. G. W. Salaman in litt. 1999). However, the species’s Area of Occupancy is fragmented, within a potential area of habitat of 8,900km2 (Renjifo et al. 2002). Its national status is currently Vulnerable under criterion C2a(i) because its small population is thought to be in decline owing to hunting and habitat conversion (Renjifo et al. 2002). Current assessments of the status of the Colombian sub-populations would be welcome.

The Venezuelan sub-population, confined to the southern Lake Maracaibo basin (Extent of Occurrence [EOO] of less than 30,000km2), is crudely estimated at fewer than 2,000 birds, and is thought to be in decline owing to hunting and the conversion of wetlands to cattle pasture (C. J. Sharpe unpubl.). The draft national threat category was therefore Endangered under criterion C2a(ii) (C. J. Sharpe unpubl.), as amended to Vulnerable under C2a(ii) in the most recent national assessment (Rodríguez and Rojas-Suárez 2008). More information is required on the national sub-population, trends and threats.

In order to reassess the status of this species, we would welcome comments on: a) recent declines, which might lead to the reclassification as Vulnerable under C1 if the decline is thought to be at least10% over 15 years (estimate of three generations; BirdLife International unpubl. data), and b) sub-population figures, which might result in the same categorisation under C2a(i) (should the largest sub-population be fewer than 1,000 individuals).

References:

Renjifo, L. M., Franco-Maya, A. M., Amaya-Espinel, J. D., Kattan, G. H. and López-Lanús, B. (2002) Libro rojo de aves de Colombia. Bogotá, Colombia: Instituto de Investigación de Recursos Biológicos Alexander von Humboldt y Ministerio del Medio Ambiente.

Rodríguez, J. P. and Rojas-Suárez, F. (eds) (2008) Libro Rojo de la Fauna Venezolana. Third Edition. Caracas, Venezuela: Provita and Shell Venezuela, S.A.

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9 Responses to Archived 2015 topics: Northern Screamer (Chauna chavaria): request for information

  1. The wetland at Valley magdalena is habitat for Northern Screamer but near to Serrania San lucas and Cienaga Ayapel the population be fewer individuals . We heard and observed flocks of only 15 individuals of this species at Cienaga Ayapel

  2. Carlos Ruiz says:

    On the Sinu River delta (Cordoba), Northern Screamer is not abundant but there is evidence of breeding (nest and chicks). Local people use this bird as a pet there. In Canal del Dique (Bolivar and Atlantico provinces) is frequently observed but in Magdalena river and Cienaga Grande de Santa Marta (Magdalena province) is very rare. It seems that Los Katios National Park (Antioquia) has the most healthy and biggest population of this bird but there are not population estimation. Loss habitat and hunting are the most important threats for this species.

  3. The species has a fairly wide distribution in Colombia including the lower Atrato, Cauca, Sinú, Nechí and lower to middle Magdalena drainages. Strictly a lowland species occupying quiet stretches of rivers as well as lakes and ponds in flat terrain (ciénagas), it has lost considerable habitat in Sucre, Córdoba, Bolívar and Magdalena due to draining of ciénagas for cattle pasture, but I cannot say how much of this has been in the last 15 years – for now, much of this area still suffers from problems of violence (guerrilla, paramilitary groups, narcos) so making a detailed census is probably not feasible. However, in areas I have visited where ciénagas remain, it is not rare and is often quite conspicuous. Hunting may be a problem in some areas but in some ciénagas it is not hunted; when used as a pet, people take the eggs to be incubated by a hen, which at least leaves the pair able to renest. For the moment, I think that Vulnerable might be the most appropriate category, but a more extensive survey of its populations remains necessary.

    • I would echo Gary Stiles’ comments. I have had the fortune or misfortune to have spent several occasions over the last decade or so observing birds in the cienagas and river deltas to the east of Serrania de San Lucas near the Magdalena river. In this part of the Magdalena drainage, the river reaches some of its highest complexity as it meanders, with many small lakes (cienagas) and islands. I disagree with Carlos Luiz’s assertion that the species is rare in the Magdalena river region, although this is true of the part of the river that approaches closer to the coast. There is a decent population of these birds below San Lucas, at least between the latitudes of Barrancabermeja and La Gloria. I have observed small parties at cienagas in the regions of the settlements of Puerto Wilches, San Pablo, Canaletal, Simiti, La Gloria and San Bernardo (Santander, Bolivar and Cesar departments) in particular. Although I have done no analysis, my impression is that this species appears to be more likely to occur in larger cienagas (>c.200 m wide or equivalent in a different shape) and absent from smaller ones (c.30m wide), prefers lakes which are more “marshy” and less “lakey” (for want of a better term) and occurs most abundantly in lakes which are bordered by trees or river mangroves rather than pastureland. It is very rarely observed along the actual Magdalena river.

      Birds are also frequently taken as pets and can be seen on the roofs of larger fincas in the region.

      This part of Colombia was subject to massive floods over the last 2-3 years. There is no data on how this may have affected Screamers. Perhaps they could have been affected by nesting and roosting sites in trees being felled by strong waters? This species has always been borderline NT/VU, and sometimes treated as VU nationally in Colombia or Venezuela. As security and greater agriculture return to certain parts of Colombia, drainage and deforestation may be increasing threats. Hunting may also return due to the fear of being associated with armed groups if carrying a gun in rural Colombia gradually dissipating.

      The status of Northern Screamers in this part of Colombia is discussed in two expedition reports, as set out below. Some of these papers are now quite old and refer to threats in the 1990s ro early 2000s rather than today but they do include some locality data and useful observations:

      Salaman PGW & Donegan TM (eds.) 2001. Presenting the first biological assessment of Serrania de San Lucas, 1999-2001. Colombian EBA Project Report Series 3. 36 pp. http://www.proaves.org/IMG/pdf/EBA_3_San_Lucas_report_2001-2.pdf

      “Single birds, pairs and small groups are typically seen perched high on the tops of tall emergent vegetation, bushes and trees, or above floating vegetation. A few observations along the Río Nechí and Río
      Cauca at Caucasia and El Bagre, but common in dense aquatic vegetation of cienagas in the río Magdalena valley from Tronca Magdalena, ca.15 km south of Puerto Berrio (a pair represent ca. 40 km southwards range extension) northwards to Simití (12 individuals). At Cienaga Canaletal, ca.20 individuals were observed high in vegetation (disturbed woodland) on the north side and 6 individuals on the south side of the lake. The population at Cienaga Canaletal is estimated at 60-80 individuals, with individuals wondering over 1.5 km distant from the lake. It is bizarre that such dense and visible populations of Northern Screamer occur so close to densely populated zones and adjacent agriculture areas. This enormous bird is neither shy nor inconspicuous, so it is
      doubtful that this species could be considered threatened from hunting for sport or food. The species is not popularly consumed and its meat may, like Horned Screamer A. cornuta, smell repulsive. Nonetheless, several local people interviewed had hunted the bird for food and eggs were taken for food and “domestication” as pets.
      Several pairs were seen in captivity (El Bagre and Barrancabermeja), but it seems doubtful that taking young
      from captivity presents a grave risk to the species given the substantial wild populations. In suitable wetland habitat in northern Colombia the species is locally common, particularly in cienagas and
      delta of the río Magdalena and río Atrato (P. Salaman et al. pers. obs.), suggesting a significant population, estimated at c. 50,000 individuals may survive. Although, the species is potentially undergoing a slow decline with the continued drainage of wetlands, the apparent lack of persecution together with extensive areas of
      suitable habitat remaining (no substantial plans exist to control the main rivers of northern Colombia), it is recommended that the Northern Screamer be classified as Near-threatened.”

      Donegan TM, Huertas-H BC, Briceno-L ER, Arias-B JJ & González-O CE (2003) Search for the Magdalena Tinamou: Project Report. Colombian EBA Project Report Series 4. 49 pp.
      http://www.proaves.org/IMG/pdf/Colombian_EBA_Proj_Rep_Ser_Tinamou_2003_with_bird_list.pdf

      “This enormous bird species is endemic to aquatic regions of the northern lowlands of Colombia and Venezuela. A pair was present and seen daily at Cienaga Sahaya in south Cesar … Interestingly, local people in the San Vicente de Chucurí region reliably reported the species at the mouth of the Río Chucurí. We were unable to confirm these reports. However, if confirmed, this would present a small but interesting easterly range extension and new locality for the species. C. chavaria appears to be considerably rarer in south Cesar than in geographically close aquatic habitats on the western side of the Río Magdalena in southern Bolivar (see Salaman and Donegan [2001]). The species’ lower levels of abundance in south Cesar may well be related to the lower quality of forest growth adjacent to aquatic habitats in the region. Salaman and Donegan [2001] found that individuals in south Bolivar were most commonly seen in treetops, which are used for nesting and as a vantage point for calling. The relative sparseness of forest growth adjacent to Cienagas in south Cesar may be why the species is less common there. Based on our talks with local people, unofficial local hunting prohibitions, enforced by paramilitaries seem to be directly and effectively preventing the last surviving pair of C. chavaria in Cienaga Sahaya from being hunted by local people.”

  4. Carolina Diaz-Jaramillo says:

    In the department of Cordoba, along the western margin of the Sinu River in the swamps of Bañó and Los Negros, and in the swamp sector comprising the districts of Cotoca Arriba, Cotoca abajo, Palo de Agua, Nariño, and Ceibapareja (municipalities of Lorica, Cordoba), about 300 individuals of Chauna chavaria were detected, including 3 chicks, 5 nests and 5 juveniles, during six months of survey work in 2012 (January-June 2012). The area surveyed covered approximately 15 km2 and if a similar number of individuals are present on the eastern bank of the Sinu, the population along the river could total 500 or more individuals. This population would appear to be healthy but it is facing threats.

    The main problem for the species along the Sinu is that its habitat is being affected by the creation of drainage dikes and poor land management, with widespread transformation for livestock grazing, as well as sedimentation and alteration of the hydrological cycle of the marshes due to up river hydroelectric schemes. While they remain relatively easy to observe, is it necessary to undertake conservation projects that involve the community, the state and the private entities concerned, especially for the protection and appropriate land use in this part of the department of Córdoba. It is also necessary to supplement the information on the life history of the species, because even though the species is a near-endemic, and is of biological significance for the country, research on the species is scarce.

    En el margen izquierdo del río Sinú, en las ciénagas de Bañó y los Negros, sector de ciénagas que conforman los corregimientos de Cotocá arriba, Cotocá abajo, Palo de Agua, Nariño, Ceibapareja (municipios de Lorica-Córdoba), se registraron aproximadamente 300 individuos, donde se observaron 3 polluelos, 5 nidos y 5 juveniles durante los monitoreos realizados en 6 meses (Enero-Junio 2012). El área de estudio tiene aproximadamente 15 Km2 y un similar número de individuos están presente al lado derecho del margen del río Sinú, la población a lo largo del río podría ser de 500 o más individuos. La problemática principal para la especie, es que su hábitat está siendo afectado por la creación de diques, y el mal manejo del suelo, el cual este siendo transformado para ganadería, así como por la sedimentación y alteración del ciclo hidrológico de las ciénagas, debido a la hidroeléctrica. Aunque su observación es relativamente fácil, es necesaria la creación de proyectos de conservación que involucren a la comunidad, al estado y a las entidades privadas competentes, especialmente para la protección y uso adecuado del suelo de esta parte del departamento de Córdoba. Igualmente, es necesario complementar la información de historia de vida de la especie, ya que a pesar de que la especie es Casi-Endémica, y es de importancia biológica para el país, investigaciones de Chavarrí son escasas.

  5. Joe Taylor says:

    Preliminary proposals

    Based on available information, our preliminary proposal for the 2014 Red List is to pend the decision on Northern Screamer Chauna chavaria and keep this discussion open until early 2015, while leaving the current Red List category unchanged in the 2014 update.

    There is now a period for further comments until the final deadline of 31 March, after which recommended categorisations will be put forward to IUCN.

    The final Red List categories will be published on the BirdLife and IUCN websites in mid-2014, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  6. Andy Symes says:

    Recommended categorisation to be put forward to IUCN

    Following further review, there has been no change to our preliminary proposal for the 2014 Red List status of this species.

    This discussion will remain open for further comments and information until early 2015, and the current Red List category will remain unchanged in 2014.

  7. I can only comment on the situation in Venezuela. Based on specimens, sightings and maps of the supposed distribution in the Sur del Lago region, the total EOO of the disjunct Venezuelan population is likely 8000–10,000 km2, perhaps smaller than this when properly mapped (approaching AOO). I would estimate that figure to be roughly 1/10th of the Colombian range and, taking into account that it is apparently uncommon and patchy in Venezuela (compared with locally common in Colombia), I surmise that the population could be < 1000, and perhaps even in the low hundreds – significantly fewer than our estimate in the last Venezuela RDB (publ. 2008). Since a rigorous baseline population estimate is lacking, there are no hard data on national population trends (that I am aware of). Anecdotally, one could argue that the species is spreading into drier areas that are being converted from dry arbustal to wetter, more open pastureland wit scattered trees and that the national population is therefore likely to be on the increase (as we did in 2008), but equally, local people claim that the bird has disappeared from some areas it formerly occupied. It is vital to determine current distribution (and any changes), population size (and trends) and actual threats.

  8. Andy Symes (BirdLife) says:

    Recommended categorisation to be put forward to IUCN

    Based on available information our recommendation for the 2015 Red List would be to continue to list Northern Screamer as Near Threatened.

    The final categorisation will be published on the BirdLife website in late October and on the IUCN website in November, following further checking of information relevant to the assessment by BirdLife and IUCN.

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