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Forbes's Blackbird Anumara forbesi
BirdLife is reviewing the status of this species for the 2017 Red List.
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Justification

Justification of Red List Category
This species has a small population, with extremely small subpopulations, and overall numbers are estimated to be declining owing to brood-parasitism by the Shiny Cowbird M. bonariensis and, to a lesser extent, habitat loss and exploitation for the pet trade. It is now known from more than ten sites, but the range is very small and severely fragmented, and it is therefore listed as Endangered.

Population justification
The population size is preliminarily estimated to fall into the band 1,000-2,499 individuals. This equates to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.

Trend justification
Despite a lack of direct estimates of the population size or trend, moderately rapid declines are suspected to be continuing, owing to habitat degradation and reduced reproductive success through nest-parasitism by M. bonariensis.

Distribution and population

Curaeus forbesi is currently known from widely scattered sites in east and north-east Brazil. The largest numbers have been recorded at Pedra Talhada, Alagoas, where the breeding population was only c.150 birds in the early 1980s, and has subsequently declined. Elsewhere in Alagoas, there have been recent records from Usina Serra Grande and near Matriz de Camaragibe (Roda 2001), and Pedra Branca (near Murici) in 1989, as well as in sugar cane plantations and pastures adjacent to forest at Engenho Coimbro (Roda et al. 2003). There have been recent records from Pernambuco at Usina Trapiche (Roda 2001) and at Mata do Estado (including flocks of up to 70 [S. Aline Roda in litt. 2007]), at São Vicente Ferrer and Engenho Água Azul in Timbaúba (Roda 2002). The ornithological group Observadores de Aves de Pernambuco lists the species for a further nine localities in Pernambuco (http://users.hotlink.com.br/oapaves/imagens/Registro.pdf), and an additional 22 are provided by Pereira et al. (2014). Over 1,400 km to the south, it is known from five sites in Minas Gerais (Mazzoni et al. 2012): the confluence of the rio Piracicaba and the rio Doce, where the highest number reported is c.40, near Pirapora (E. O. Willis in litt. 1999), and the borders of Parque Nacional Cavernas do Peruaçu (Vasconcelos et al. 2006). Despite the discovery of new sites, the known range of this species is still thought to be very small and severely fragmented.

Ecology

It inhabits forest edge, adjacent marshy areas and sugarcane plantations. The diet includes fruit, insects and possibly nectar taken from the flowers of sugar cane (S. Aline Roda in litt. 2007). Breeding takes place in the rainy season, usually March-June. Nests are mainly situated in cultivated mango Mangifera indica trees. Mean clutch-size is 2.84 (1-4) and two clutches are laid per season. A 4-10 day delay between finishing nest construction and laying makes the species highly susceptible to brood-parasitism by the Shiny Cowbird Molothrus bonariensis.

Threats

Widespread habitat destruction, particularly in north-east Brazil, has even reduced forest-edge areas. However, the species might be able to withstand the conversion of forests to sugarcane plantations to some degree. At Pedra Talhada, the recent decline is also attributed to brood-parasitism by M. bonariensis. In 1981-1986, 64% of studied nests were parasitised and, in 1987, this was 100%. It has been observed in trade and there is potential confusion with the valued G. chopi.

Conservation actions

Conservation Actions Underway
Officially recognised as Vulnerable in Brazil (Silveira and Straube 2008, MMA 2014). It is legally protected in Brazil, and occurs in Rio Doce State Park and Pedra Telhada Biological Reserve. Protection at Pedra Talhada is enforced by guards and apparently welcomed by local communities, but this species mostly occurs outside the reserve (A. Studer per A. Whittaker in litt. 1999). At Rio Doce, it is regularly recorded only in a very small area between the park entrance and Lagoa Carioca (T. A. de Melo Júnior in litt. 1999). Ecological studies and experiments on destroying M. bonariensis eggs are in progress at Pedra Talhada.

Conservation Actions Proposed
Urgent need to establish a protected area at Mato do Estado (S. Aline Roda in litt. 2007). Survey known sites in Alagoas and Pernambuco. Re-examine museum collections of G. chopi to disclose additional specimens of this species and identify areas for surveys. Survey to elucidate the species's status at Rio Doce. Investigate protecting habitat near Pirapora. Study and control parasitism by M. bonariensis.

Identification

21-24 cm. Medium-sized black icterid. Entirely black, not glossy. Slender bill, without grooves and equal to head length. Straight and flat culmen. Similar spp. Chopi Blackbird Gnorimopsar chopi is glossier and shows shorter, grooved bill with distinctive curve to rounded culmen. Voice Harsh, unpleasant, repeated buzzy notes and chatters. Also loud and rough check check notes reported. Call is a loud, nasal tuí-lit.

Acknowledgements

Text account compilers
Gilroy, J., Harding, M., Sharpe, C J

Contributors
Willis, E., Whittaker, A., Melo Júnior, T., Aline Roda, S.


Recommended citation
BirdLife International (2017) Species factsheet: Anumara forbesi. Downloaded from http://www.birdlife.org on 18/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/10/2017.