Archived 2011-2012 topics: Mexican Sheartail (Doricha eliza): request for information

This discussion was first published on Dec 2 2010 as part of the 2011 Red List update.

Initial deadline for comments: 31 January 2012.

Link to BirdLife species factsheet for Mexican Sheartail

Mexican Sheartail Doricha eliza is listed as Near Threatened under criterion B1a+b(i,ii,iii,iv); C1. Its Extent of Occurrence is estimated at 9,500 km2, and its population, which is likely to be moderately small, is locally threatened by habitat loss and degradation. Thus its population and range are likely to be experiencing declines; however, the population is not considered to be severely fragmented or restricted to a few locations.

Up-to-date information is requested on this species’s total population size, estimated rate of decline over 12 years (estimate of three generations) and the severity of threats. Particular detail is requested on the level of habitat fragmentation within its range, which would be considered to be severe if over 50% of suitable habitat was in patches too small to support viable populations.

El colibrí cola endida (Doricha eliza): solicitud de información

Esta información fue publicada por primera vez en 02 de diciembre 2010 como parte de la actualización de la Lista Roja de 2011, pero sigue abierta a comentarios para facilitar la reevaluación en el 2012.

Plazo inicial de observaciones: 31 de enero de 2012.

Enlace a la hoja de datos de BirdLife El colibrí cola endida

El colibrí cola endida Doricha Eliza aparece como Casi Amenazado bajo el criterio B1a + b (i,ii,iii,iv), C1. Su Extensión de Ocurrencia (EOO) se estima en 9.500 km2, y su población, que es probable que sea moderadamente pequeña, se encuentra amenazada a nivel local por la pérdida y degradación del hábitat. Por lo tanto, es probable que tanto su población como distribución estén experimentando una disminución; sin embargo, la población no se considera como severamente fragmentada ni restringida a unas pocas localidades.

Se solicita información actualizada sobre el tamaño total de la población de esta especie, la tasa estimada de disminución durante un período de 12 años (equivalente al estimado de tres generaciones) y la gravedad de las amenazas. Se requiere información detallada sobre el nivel de fragmentación de su hábitat, la cual sería considerada como severa si más del 50% del hábitat apropiado restante se encuentra en parches demasiado pequeños para mantener poblaciones viables.

The following document was sent by Pronatura on 16 February 2012: Doricha eliza Pronatura Feb12

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4 Responses to Archived 2011-2012 topics: Mexican Sheartail (Doricha eliza): request for information

  1. As it is know Doricha eliza have two separated populations, one in the Veracruz center and another in the North of the Yucatan Peninsula. Both populations faced different treats and have conservation status.
    Taking into account our field data to Veracruz (Ortiz-Pulido 2000, 2003, unpublished, Ortiz-Pulido et al. 1998, 2002, Ortiz-Pulido and Díaz 2001, Díaz-Valenzuela et al. 2011) I conclude that the Veracruz population is near of local extinction. This population is restricted to an area of least than 800 km2. Its population number is least than 2500 individuals. Its nest sites are restricted to few natural wet pastures, which are very located in a small area in Veracruz, and we registered that the area covered by the pastures detected is now been change to residencial develops. Population trends are stables (at least between 1997 and 2003 years; Ortiz-Pulido et al. 2002, Díaz y Lara 2005). Nowadays, no one natural protected area is conserving the habitat of D. eliza Veracruz population. To me, the Veracruz population must to be considered Endangered.
    To the Yucatan population we have not enough data to express a conclusive idea about its conservation status. However, there are some anecdotic observations (Howell and Webb 1995, Ortiz-Pulido et al 2002, Ortiz-Pulido, Ortega y Leyequien unpublished). We know their distribution (near to 500 km2, Ortiz-Pulido unpublished data) and its relative abundance (abundant to uncommon in places near to the beach; Howell and Webb 1995, Ortiz-Pulido, Ortega y Leyequien unpublished), but not their population size, neither their breeding requirements. Even that, the distribution of this population is protected in at least three natural areas. So, to me, the Yucatan population, while not more data is published, must be considered as vulnerable or near threatened.
    Without more data, I believe that D. eliza, as species, must to be considered as Endangered or Vulnerable.

    Cordially

    Raul Ortiz-Pulido

    Literature cited
    Díaz, R. and N.Z. Lara. 2005. Monitoreo poblacional y seguimiento de nidos del colibrí Doricha eliza en Veracruz, México. Tesis de licenciatura. Facultad de Biología, Universidad Veracruzana. Xalapa, Veracruz, México.
    Howell, S.N.G. and S. Webb. 1995. A guide to the birds of Mexico and Northern Central America. Oxford.
    Ortiz-Pulido, R., E. Flores y R. Ortiz. 1998. Descripción del nido de Doricha eliza y ampliación de su rango. Ornitología Neotropical 10: 223-224.
    Ortiz-Pulido, R. 2000. La autopista Cardel-Perote puede extinguir una especie de colibrí. Diario de Xalapa, Domingo 23 de enero. Página 12/a.
    Ortiz-Pulido, R. y R. Díaz. 2001. Distribución y densidad de colibríes en la zona baja del centro de Veracruz, México. Ornitología Neotropical 12: 297-317.
    Ortiz-Pulido, R., A. T. Peterson, M. B. Robbins, R. Díaz, A. G. Navarro y G. Escalona-Segura. 2002. The mexican Sheartail (Doricha eliza): Morphology, behavior, distribution, and endangered status. Wilson Bulletin 114: 153-160.
    Ortiz-Pulido, R. 2003. Colibrí cola endida (Doricha eliza). En Oliveras, A. y Gómez de Silva, H. (Eds.), Conservación de Aves en México. Birdlife International, Lynx Editions y CIPAMEX.
    Díaz-Valenzuela, R, Lara-Rodríguez, N.Z., Ortiz-Pulido, R., González-García, F. y Ramírez Bautista, A. 2011. Some aspects of the reproductive biology of the Mexican Sheartail (Doricha eliza) in central Veracruz. Condor 113: 177-182.
    Ortiz-Pulido, R. Unpublished. Doricha eliza. Ficha técnica. CONABIO, CIPAMEX.

  2. Sorry, I forgot to say that I do not believe that D. eliza have more than 20,000 individuals in the field. So, I did not agree with Panjabi sugestion (as cited in Birdlife International 2012) about that D. eliza have between 20000-50000 individuals in field. As I say previously, to Veracruz we estimated near of 2500 individuals (0.033 ind/ha; Ortiz-Pulido et al 2002), and considering (optimistically) three-four times the veracruz abundance to the Yucatan population (i.e. 0.099 to 0.132 ind/ha) and the Yucatan distribution (505 km2), I believe in Yucatan we can have between 6000-10000 individuals. However, it reamians to be tested in field.

    Cordillay

    Raul

    Literature cited

    BirdLife International (2012) Species factsheet: Doricha eliza. Downloaded from http://www.birdlife.org on 27/01/2012. Recommended citation for factsheets for more than one species: BirdLife International (2012) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/01/2012.
    Ortiz-Pulido, R., A. T. Peterson, M. B. Robbins, R. Díaz, A. G. Navarro y G. Escalona-Segura. 2002. The mexican Sheartail (Doricha eliza): Morphology, behavior, distribution, and endangered status. Wilson Bulletin 114: 153-160.

  3. The Doricha eliza population of the Yucatan Peninsula is mainly found in the coastal dune scrub, but also in the edges of mangrove areas (Howell and Webb 1995).
    Most of the coastal dunes in Mexico have deterioration and fragmentation (Castillo et al., 1991), and the Yucatan State is not the exception, the coastal dune has lost more than 50% of its original vegetation (Duran et al., 2007 cited by Torres et al., 2010). The coastal dune scrub basically has been modified by urban development, port infrastructure, coconut plantations, but mainly by the development of summer houses. These activities, to be done, need to remove all the coastal dune vegetation. This has happened in places like Celestun, Sisal, Santa Clara, Progreso, Telchac and El Cuyo. Nowadays most of the land is private and it is anticipated that this urban development will continue in the coming years (Euan-Avila et al., 2007).

    Personal observations suggest that D. eliza is closely related to the coastal dune vegetation, and their presence in areas of mangrove and deciduous forest is not common. In some places such as Sisal, Yucatan (21 ° 9’35 .30 “N – 90 ° 3’39 .52″ W) the main area of distribution may be restricted by the sea and the mangroves to a strip of 120-180 meters wide of coastal dunes, and these features are repeated across many places of the Yucatan Peninsula.

    It is important to note that in the Yucatan State there are only 6147 hectares of coastal dunes, and its rate of annual loss is 52.7 ha. (Euan-Avila et al., 2007).

    Because of the characteristics of northern Yucatan Peninsula (rias, mangroves, petens) maybe the 500 km2 that have been mentioned as its range is greater than real. A one year recent work, done only 2 km from Yucatan coast, not record the presence of D. eliza (Chable et al., 2008). Some similar happens in a transect done in Celestun just 800 meters from the coast in a mangrove area (Ortega-Pimienta et al., unpublished data). However, there are unusual records just over 2 km of the coast (Santamaría unpublished data), where one individual was recorded in a 1 km transect.

    It is necessary to produce more information on the distribution and population size in the Yucatan Peninsula. As mentioned by Raúl Ortiz-Pulido (last posts), the relative abundance of D. eliza in the narrow strip of coastal dune vegetation may be abundant to uncommon, and its presence becomes more rare with increasing distance from the coast.

    I also agree with estimates of population size (Raúl Ortiz-Pulido last post ) that appears more realistic; as well as proposals to change the status to vulnerable or endangered, taking into account the situation of the two populations.

    Cordially

    Joel F. Ortega-Pimienta

    Literature cited
    Castillo, S., Pompa, J. and Moreno-Casasola, P. 1991. Coastal sand dune vegetation of Tabasco and Campeche, Mexico. Journal of vegetation science 2: 73-88.

    Chablé-Santos J. B., González-Rojas J. I., Peña-Peniche L. A. and Pasos-Enríquez R. M. 2008. Bird diversity in the petens of the Yucatan State, Mexico. Ornitología Neotropical 19: 55-70

    Durán R., Méndez, M., Dorantes,E.A. and Dzib, G. 2007. Evaluación, diagnóstico y restauración de la vegetación y flora nativa de la duna costera en el norte de Yucatán, Informe final, SEMARNAT, Mérida, México.
    Euán-Ávila j., García A. and Liceaga-Correa M. A. 2007. Programa de Ordenamiento Ecológico del Territorio Costero del Estado de Yucatán. CINVESTAV, CICY, ITC, ITM, UADY. Informe técnico final.

    Howell, S. N. G. and S. Webb. 1995. A guide to the birds of Mexico and northern Central America. Oxford University Press, New York.
    Torres, W., Méndez, M., Dorantes, A. and Durán, R. 2010. Estructura, composición y diversidad del matorral de duna costera en el litoral yucateco. Boletín de la Sociedad Botánica de México, 86: 37-51

  4. Joe Taylor says:

    Pronatura have sent a document with information on this species, and it is posted just below the forum topic.

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