NT
White-breasted Antbird Rhegmatorhina hoffmannsi



Justification

Justification of Red List Category

Based on a model of future deforestation in the Amazon basin, it is suspected that the population of this species will decline by 25-30% over the next three generations, and it has therefore been uplisted to Near Threatened.

Population justification
The global population size has not been quantified, but this species is described as 'common' (Stotz et al. 1996).

Trend justification
This species is suspected to lose 20.2-24.3% of suitable habitat within its distribution over three generations (14 years) based on a model of Amazonian deforestation (Soares-Filho et al. 2006, Bird et al. 2011). Given the susceptibility of the species to fragmentation and/or edge effects, it is therefore suspected to decline by 25-30% over three generations.

Distribution and population

This species occurs from the east bank of the rio Madeira south and east through Rondônia to west Mato Grosso on the Serra dos Parecís and Serra das Ararasin in central Amazonian Brazil.

Ecology

The species is found at elevations up to 300 m (Ridgely and Tudor 1994), and is common in undergrowth of tropical lowland evergreen forest. It is considered to be an obligate ant-following species, obtaining virtually all of its prey items from attending primarily Eciton burchelli swarms and seizing arthropods that are flushed by the ants. Breeding is thought to take place during the rainy season, with fledging occurring from February onwards.

Threats

Projected deforestation is the primary threat affecting this species (Soares-Filho et al. 2006, Bird et al. 2011). The species is highly sensitive to human disturbance and is suffering from widespread deforestation, particularly in Mato Grosso and Rondônia, which has increased markedly since the 1960s owing to road building, ranching, smallholder agriculture, mining and hydroelectric development (Cleary 1991, Ridgely and Tudor 1994, Stotz et al. 1996). The principal threats are the expansion of the agricultural frontier as a direct result of highway construction (Cleary 1991) and commercial logging, which is increasingly signficant (M. Cohn-Haft in litt. 1999). Although the rate of highway construction declined in the 1990s, clearance of forest for cattle ranching and other agriculture has continued throughout Rondônia and Mato Grosso, and fragmentation of the remaining forest is likely to further reduce the effective range size of the species.

Conservation actions

Conservation Actions Underway

A significant proportion of the range of the species now lies within Protected Areas (A. Lees in litt. 2011), including the Pacaás Novos National Park in Rondônia.

Conservation Actions Proposed

Expand the protected area network to effectively protect IBAs. Effectively resource and manage existing and new protected areas, utilising emerging opportunities to finance protected area management with the joint aims of reducing carbon emissions and maximizing biodiversity conservation. Conservation on private lands, through expanding market pressures for sound land management and preventing forest clearance on lands unsuitable for agriculture, is also essential (Soares-Filho et al. 2006). Campaign against proposed changes to the Brazilian Forest Code that would lead to a decrease in the width of the areas of riverine forest protected as Permanent Preservation Areas (APPs), which function as vital corridors in fragmented landscapes.

Identification

14-15cm, 28-34g. Large bare periorbital patch, ear coverts, breast sides, breast and throat all white. Top of head black in male, chestnut brown in female. Upperparts olive-brown, female has buff-edged black tips to coverts, mantle, and rest of underparts while the male is plain, and has grey underparts. Similar spp. Bicoloured Antbird Gymnopithys leucapsis has a similar pattern of white throat and breast, and the nominate has white extending onto face sides. This does not extend across the whole of the ear coverts or the breast sides, both of which are black. The periorbital patch is also smaller than in R. hoffmansi. Voice Loudsong begins with a long slurred whistle followed by 6-7 shorter whistles becoming downslurred and ending with a few lower pitched burry notes. Calls are similar to R. gymnops; a harsh chirr and an abrupt chip.

Acknowledgements

Text account compilers
Butchart, S., Ekstrom, J., Fisher, S., Harding, M., Symes, A.


Recommended citation
BirdLife International (2017) Species factsheet: Rhegmatorhina hoffmannsi. Downloaded from http://www.birdlife.org on 13/12/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 13/12/2017.