Data Zone
Justification of Red List category
This species's population size is likely to be very small, and composed of very small subpopulations. The population size is inferred to be declining as a result of forest loss, largely through conversion to agriculture. For these reasons, it is listed as Vulnerable.
Population justification
The species appears to be naturally rare and has localised subpopulations. Based on the opinion of experts with experience of research within the species's range, the total population size is thought to be smaller than 10,000 mature individuals (de Melo Dantas and Albano 2018). Based on the maximum number of individuals seen at one locality (700), the population size is estimated to fall within the band 1,000-2,499 individuals (de Melo Dantas and Albano 2018, D. Lima in litt. 2020), which roughly equates to 667-1,667 mature individuals. The population size is therefore placed in the band 600-10,000 mature individuals.
The species is found in localised subpopulations separated from large areas of unsuitable habitat, and there are no records of individuals moving large distances between habitat patches (de Melo Dantas and Albano 2018). The species is therefore thought to have small subpopulations with fewer than 1,000 mature individuals in each subpopulation (de Melo Dantas and Albano 2018).
Trend justification
The area of forest with at least 30% canopy cover within the species's mapped range declined by 10% over a period of three generations (13 years) from 2006-2019 (Global Forest Watch 2020). The species is known to inhabit forest edges as well as sugar cane and mango plantations, and non-forest habitats, so it is not known whether the reduction in forest habitat has resulted in a similar reduction in population size, but the population size is tentatively inferred to be declining at a suspected rate of up to 10% over three generations (13 years).
Anumara forbesi is known from widely scattered sites in Brazil, where it occurs in Pernambuco and Alagoas in the northeast, and over 1,400 km to the south in Minas Gerais, east Brazil. There is some doubt over the identification of records from northern Minas Gerais and these records require further verification (Mazzoni et al. 2012, L. G. Mazzoni in litt. 2020).
It inhabits forests, forest edge, adjacent marshy areas and river edges and sugarcane and mango plantations (Fraga and Sharpe 2016). The diet includes fruit, insects and possibly nectar taken from the flowers of sugar cane (S. 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.
Widespread habitat destruction, particularly in north-east Brazil, through conversion to agriculture, has caused considerable habitat loss and degradation, and even reduced forest-edge areas. However, the species might be able to withstand the conversion of forests to sugarcane and or mango plantations to some degree. At Pedra Talhada, a decline has been attributed to brood-parasitism by Molothrus bonariensis, which is favoured by habitat conversion to agriculture. Studies have indicated very high levels of nest parasitism by Molothrus bonariensis, including a study in Alagoas that found that 64% of nests were parasitised, and most parasitised nests were abandoned, and subsequent studies that have incated a 100% rate of nest parasitism (de Melo Dantas and Albano 2018). M. rufoaxillaris recently colonised areas of eastern Brazil and may pose an additional threat through nest parasitism (de Melo Dantas and Albano 2018). It has been observed in trade (de Melo Dantas and Albano 2018, Viana Costa et al. 2018).
Conservation Actions Underway
Officially recognised as Vulnerable in Brazil (Silveira and Straube 2008, MMA 2014, ICMBio 2018). It is legally protected in Brazil, and is included in the National Action Plan for the Conservation of Birds of the Atlantic Forest (ICMBio 2017). It occurs in several protected areas including Matas do Sistema Gurjaú wildlife refuge, Maurício Dantas private natural heritage reserve, Murici ecological station, Pedra Talhada biological reserve and Rio Doce state park. Protection at Pedra Talhada is enforced by guards and apparently welcomed by local communities, but the species mostly occurs outside the reserve (A. Studer per A. Whittaker in litt. 1999). Ecological studies and experiments on destroying M. bonariensis eggs have been carried out at Pedra Talhada.
Conservation and Research Actions Proposed
Carry out surveys to better assess the species's population size. Monitor population and habitat trends. Study the impact of nest parasitism by Molothrus spp. Protect the remaining habitat within its range, including habitat outside forests. Improve enforcement at protected areas where the species occurs.
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.
Text account compilers
Wheatley, H.
Contributors
Aline Roda, S., Brusland, S., Gilroy, J., Harding, M., Lima, D., Mazzoni Prata Fernandes, L.G., Melo Júnior, T., Sharpe, C.J., Whittaker, A. & Willis, E.O.
Recommended citation
BirdLife International (2024) Species factsheet: Forbes's Blackbird Anumara forbesi. Downloaded from
https://datazone.birdlife.org/species/factsheet/forbess-blackbird-anumara-forbesi on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/12/2024.