Archived 2010-2011 topics: Mountain Grackle (Macroagelaius subalaris): request for information

Posted on December 1, 2010 by Andy Symes (BirdLife)

Link to BirdLife species factsheet for Mountain Grackle

Mountain Grackle Macroagelaius subalaris is currently listed as Endangered under criterion B1a+b(iii), based on the species having an Extent of Occurrence (EOO) of less then 5,000 km2, in which its habitat is severely fragmented and declining in area, extent and/or quality.

It has been suggested by O. Cortes (in litt. 2007) that the species should be uplisted to Critically Endangered on the basis that the population is undergoing a decline of at least 80% over 14 years (three generations); however, further evidence is required that such a decline is being observed or is suspected to be taking place. Comments are invited on the species’s likely population trend and estimated rates of habitat loss.

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3 Responses to Archived 2010-2011 topics: Mountain Grackle (Macroagelaius subalaris): request for information

  1. Oswaldo Cortes says:
    January 21, 2011 at 5:02 am

    En Cundinamarca, en la Aguadita, Aguabonita y Subía de los municipios de Silvania y Fusagasuga donde existía la especie, los bosques de roble y bosque andino han sido talados en su mayor parte para adecuar pastizales para ganadería y agricultura. Fragmentos pequeños de vegetación secundaria no mayores a 50 ha, persisten en las laderas empinadas y se encuentran bastante aislados uno de otros. Exploraciones a estas regiones en búsqueda de poblaciones de la especie han sido infructuosas, donde al parecer hay una extinción local de la especie.

    La especie continua perdiendo hábitat por deforestación en varios municipios y regiones del departamento de Santander donde la especie se encuentra (municipio de California, Angostura, Páramo de Romeral y Suratá) donde además se presentan actividades de minería, principalmente de extracción de oro que han reducido los bosques de roble.

    Las poblaciones de Macroagelaius subalaris de Soatá y alrededores del S.F.F Guanentá-Alto Río Fonce se encuentran amenazadas por la destrucción significativa del bosque de roble y mixto. La tala rasa para la adecuación de los terrenos para cultivo y para pastoreo son los dos fenómenos de mayor impacto ecológico en la zona. Igualmente existe venta de leña de madera de roble que es vendido en el mercado local.
    La dependencia ecológica de esta especie por los bosques de roble (anidación y alimentación), conllevan a la reducción de las poblaciones de este icterido

  2. Andy Symes says:
    January 31, 2011 at 3:24 pm

    Fundacion ProAves have provided the following information:

    Please refer to the comments from Thomas Donegan in the previous version of this proposal concerning the population in the Yariguíes mountains (http://www.birdlifeforums.org/WebX/.2cba5400). The Yariguíes population is clearly the core remaining population for this species with large tracts of inaccessible habitat where the species occurs. The population in the main East Andes is highly fragmented and of questionable viability, as described in the proposal and by other participants on the forum. However, the Yariguíes massif constitutes a c.100 km long, steep, forested mountain range with considerable forest at suitable elevations for this species. As a result, it does not mandate upgrading.

    In January 2011, on Proyecto YARE II (a project supported by ProAves and Birdlife / CLP Programme), we found a very significant new population for this species in Serrania de las Yariguíes at Reserva Paramo La Floresta. This location is a private nature and water-source reserve owned by a private landowner and administrated by the mayoralty of the municipality of Zapatoca, Santander. This locality includes secondary growth, sub-páramo, some oak forest fragments and, importantly, a humedal (marshland) at around 2600m elevation. In the forest and forest border surrounding the humedal, Mountain Grackle was the most conspicuous and possibly the most abundant bird species. Several flocks, each of tens of individuals, roamed this region. Birds were seen largely in the oaks bordering the humedal but also foraged on fruit in small shrubs within the humedal and used the humedal for drinking water. The Paramo La Floresta reserve probably holds at least 100 individuals of this species. In other sites in Serranía de los Yariguíes, we had found the species to be rare in primary montane forest treefall gaps or landslides and at forest borders, where small numbers can be found. Individuals sometimes associated loosely with larger groups of Mountain Cacique Cacicus leucorhamphus. In contrast, at Paramo La Floresta, very few individuals of Mountain Cacique were observed among much larger flocks of Mountain Grackle.

    Natural forest / humedal borders appear to be an important core natural habitat for the species. Now that this is known, searches and conservation efforts for this species may be capable of being better focused. Notably, most humedales in the East Andes are not bordered by natural oak forest, but by pastureland – and probably do not hold the species for this reason. Our observations in montane forest / farmland borders at other sites in the Yariguíes are in a habitat which replicates certain aspects of a forest / humedal ecotone. During EBA and YARE I projects in the Yariguíes in 2003-2005, we observed various other high elevation humedales (from distance) within the Yariguíes range. Most of these are difficult to access and found on isolated plateaux of steep, forested mountains but they probably support important populations of Macroagelaius.

    As a result of these findings, assuming similar populations in other humedales of the Yariguíes, the population of Mountain Grackle in Serranía de las Yariguíes can be considered to be likely at least 800 individuals (see previous comments). We consider the species warrants maintaining as Endangered rather than upgrading to Critical. Whilst has already lost the vast majority of its habitat in the Eastern Cordillera, the Yariguíes population appears strong. It should be looked for in other forested humedales and the Zapatoca mayoralty should be supported further in its efforts to protect this important new locality.

    Fundacion ProAves (in press) The status of various threatened or potentially threatened birds in Colombia. Conservación Colombiana 14

  3. Oswaldo Cortes says:
    February 4, 2011 at 2:56 am

    Atento saludo,

    Leo y felicito la labor adelantada en Yariguies. Pero su interés de solo proteger las poblaciones de Macroagelaius subalaris, presente en esta región es egoísta. Hay labores de conservación y estudios ecológicos en el Santuario de fauna y flora guanenta (Santander), Soata, Tipacoque (Boyaca) que han evidenciado la notable presencia y abundancia de la especie en estas regiones. Por tanto aquí hay también hay trabajos y poblaciones que deben seguir siendo monitoreadas. También hago un llamado de atención que la población presente en el páramo de Angostura, esta en estado critico, por la intensa actividad minera que ha conllevado aun detrimento dramático de los bosques de roble, hábitat de esta especie, por tanto aquí debemos trabajar todos para apoyar las iniciativas locales que tienen los grupos ecológicos de esta región. Así que cuando se deba salvar una especie no se debe pensar en una sola población, si no en todas las poblaciones que existan, dado que esto contribuye al flujo de genes de las poblaciones y a la integración de la comunidad local que participe en estas iniciativas

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