Archived 2010-2011 topics: Cock-tailed Tyrant (Alectrurus tricolor): request for information

Link to BirdLife species factsheet for Cock-tailed Tyrant

Cock-tailed Tyrant Alectrurus tricolor is listed as Vulnerable under criteria A2c; A3c; A4c on the basis that a population decline of 30-49% over 10 years is suspected in the past and projected in future, owing to the loss and degradation of its habitats through conversion to cultivation, livestock-farming, mining operations, afforestation, fires and invasive plant species (Parker et al. 1991, Machado et al. 1998, H. del Castillo in litt. 2007).

It has been suggested that the species is present in good numbers in Bolivia (B. Hennessey in litt.), prompting a re-evaluation of its rate of decline and threat status. Up-to-date information is thus requested from all range states on this species’s population size, but in particular the likely population trend and the severity of threats faced by the species. The population trend should be estimated for a period of 11 years (estimate of three generations).

Machado, A. B. M., da Fonseca, G. A. B., Machado, R. B., Aguiar, L. M. De S. and Lins, L. V. (1998) Livro Vermelho: das espécies ameaçadas de extinça1o da fauna de Minas Gerais. Belo Horizonte: Fundaça1o Biodiversitas.

Parker, T. A., Castillo, U. A., Gell-Mann, M. and Rocha, O. O. (1991) Records of new and unusual birds from northern Bolivia. Bull. Brit. Ornithol. Club 111: 120-138.

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2 Responses to Archived 2010-2011 topics: Cock-tailed Tyrant (Alectrurus tricolor): request for information

  1. Rob Clay says:

    Alectrurus tricolor remains very rare in Paraguay, and is currently known from just a handful of sites. The site holding the largest population (Laguna Blanca in San Pedro department) has lost a very significant amount of cerrado grassland habitat in recent years (conversion to cattle pastures, crops and Eucalyptus plantations). These same threats, plus overgrazing and frequent fires affect probably all appropriate habitat in the country, and the species is considered Endangered at the national level.

  2. Joe Taylor says:

    The following extracts are taken from comments by Raphael E. Fernandes Santos, sent on 30 January 2011:

    In Brazil, the Cock-tailed Tyrant (Alectrurus tricolor) occurs from the Central portion of the country (States of Mato Grosso, Goiás, Minas Gerais and Espírito Santo) until Rio Grande do Sul (the southern one).
    Its situation in Brazil is not so good due to the habitat loss. The rhythm of the grasslands conversion in productive areas is increasing a lot.
    In the other hand, there is a place where the species is fairly common in Brazil. This place is the Emas National Park, an area located in Central Brazil, in Goiás State, near the border with Mato Grosso do Sul State. In this area the species in often seen. The mentioned Federal Reserve has an important grassland inhabited by a couple of other threatened bird species.

    Nowadays, the species can be found in other places in Central Brazil but its population seems to be decreasing at the same time the natural grasslands are being converted in soy plantations. There is a record for the South Pantanal (CESTARI, 2006), but it is not commonly expected at this huge wetland.

    In South Brazil, the Cock-tailed Tyrant is very rare, listed in every regional red list. There are few records of the species for the Paraná State . . .

    In Paraná State, the species is endangered because its habitat is being drastically modified. The main purpose is the Pine plantations (Pinus spp.). In São Paulo State, the species is considered critically endangered and the natural grasslands are becoming very scarce.
    Considering the Brazil’s records of the Cock-tailed Tyrant, it is an uncommon species that need a special type of humid grassland, generally used for the agriculture. In South Brazil it is very rare and its situation is bad. Otherwise, the population that uses the Emas National Park provides him another concept. Maybe the category “vulnerable” could be the best classification for this species in Brazil.

    CESTARI, C. 2006. Primeiro registro documentado de Alectrurus tricolor para o Pantanal, Brasil. Revista Brasileira de Ornitologia, 14 (2): 155-156.

    SANTOS, R. E. F. 2007. Novo registro documentado do galito Alectrurus tricolor (Vieillot, 1816) para o estado do Paraná, Brasil. Atualidades Ornitológicas, 140, p.12-13.

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