Proposal (208) to South American Classification Committee

 

Add Gallinula angulata to Main List

 

Background: The Lesser Moorhen is widespread in sub-Saharan Africa, inhabiting freshwater wetlands (Taylor and van Perlo 1998).

 

New record from Bencke et al. (2005): On 10 January, in the morning, a Lesser Moorhen was seen floating on the water at the entrance of the bay as the inflatable boat used in landing operations approached the archipelago*. In the afternoon of the same day, the bird was found weakening outside the bay by fishermen and was brought to the scientific station. The individual, which subsequently died, was collected and deposited at the Museu de Ciźncias Naturais [in Porto Alegre, Rio Grande do Sul, Brazil] (MCN 2742).

 

There are three pictures of this specimen available at:

 

http://www.cbro.org.br/CBRO/images/gal_ang1.JPG http://www.cbro.org.br/CBRO/images/gal_ang2.JPG 

http://www.cbro.org.br/CBRO/images/gal_ang3.JPG

 

* The Archipelago of Sčo Pedro and Sčo Paulo (0°55'N, 29°20'W) is a small and isolated group of rocky islets lying c.960 km northeast of the coast of Rio Grande do Norte, Brazil,

 

Literature Cited:

 

Bencke, G. A., P. Ott, I. Moreno, M. Tavares, and G Caon (2005) Old World birds new to the Brazilian territory recorded in the Archipelago of Sčo Pedro and Sčo Paulo, equatorial Atlantic Ocean. Ararajuba 13 (1):126-129.

 

Taylor, B. and B. van Perlo (1998) Rails. A guide to the rails, crakes, gallinules and coots of the world. New Haven and London: Yale University Press.

 

J. F. Pacheco, March 2006

 

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Comments from Robbins: "A tentative "yes". The identification is correct, but the question on whether this might have been a ship-assisted individual should be raised and addressed."

 

Comments from Silva: "YES (tentative), but we need to think about Mark's point."

 

Comments from Remsen: "YES, with a response to Mark's point. Many landbird vagrants that cross large water gaps are ship-assisted -- anyone who has spent time offshore knows that migrating landbirds alight regularly on ships (as well as debris, oil platforms, and so on), where they may rest, feed, and drink. There is no way to distinguish those that did this from those that did not, and so checklist committees have typically been concerned not with "assisted" but rather "restrained," i.e., held in captivity on ships after landing there. For species with long-distance dispersal capabilities, such as virtually any volant species in the Rallidae, individual vagrants are considered "not restrained" and thus valid records unless evidence is mustered to the contrary."

 

Comments from Nores: "NO. Yo pienso que la presencia de esta especie en el Archipiélago de San Pedro y San Pablo es un hecho muy casual (o accidental), como para estar incluida en la lista principal. A pesar de que existe un ejemplar coleccionado no es garantía de que la especie haya llegado por si misma e incluso puede haber venido como polizón en un barco como sucede con muchas aves. El hecho de que no existan registros previos en América, apoyaría que la especie no es un "vagrant" frecuente como en el caso anterior. Además, se agrega el hecho de que el archipiélago de San Pedro y San Pablo está ubicado a 1000 km de la costa de Sudamérica, casi a mitad de camino entre África y Sudamérica, lo que relativiza también que la especie sea un ave sudamericana."

 

Comments from Zimmer: "YES. I would echo Van's comments regarding ship-assisted birds. Hitching rides on passing ships is something that birds do naturally. The possibility that a given vagrant might have done this, in absence of any evidence that it was forcefully restrained or held captive on a ship, should not, in my opinion, disqualify it from being added to the list. As Van notes, this happens all of the time (particularly with smaller birds), and there is simply no way of knowing one way or the other."