Data Zone
Justification of Red List category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km² combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Population justification
The global population size has not been quantified. The species is described as 'uncommon'; it occurs at low densities (Stotz et al. 1996, A. Lees in litt. 2022).
Trend justification
Due to its dependence on tall, undisturbed humid forests (Schulenberg 2020), the species is suspected to undergo a decline as habitat is lost and degraded.
The population trend has not been quantified directly. Within the range, tree cover is lost at a rate of 7% over ten years, having accelerated to approximately 9.5% loss since 2016 (Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). Given its strict habitat requirements, and additional impacts from fires and selective logging (Barlow et al. 2016, A. Lees in litt. 2022), the rate of population decline is suspected to be higher than the rate of tree cover loss alone, and is therefore here placed in the band 10-19% over ten years.
The species occurs in central Brazil south of the Amazon in eastern Amazonas and Pará south to Rondônia and central Mato Grosso, as well as eastern Bolivia.
The species inhabits tropical lowland forest from near sea level to 500 m. It is dependent on tall, undisturbed 'terra firme' forests and does not tolerate secondary habitats (A. Lees in litt. 2022). It forages entirely in the upper canopy layer, presumably feeding on invertebrates, and is often associated with mixed-species flocks. Individuals in breeding condition were observed in June and September, but the species' ecology is largely unknown.
The primary threat to this species is accelerating deforestation in the Amazon basin as land is cleared for cattle ranching and soy production, facilitated by expansion of the road network; it is patchily distributed and strongly susceptible to degradation and fragmentation due to its reliance on primary forest (Soares-Filho et al. 2006, Bird et al. 2011, A. Lees in litt. 2011, 2022). Changes to the Brazilian Forest Code reduced the percentage of land a private landowner is legally required to maintain as forest and included an amnesty for landowners who deforested before July 2008 (Bird et al. 2011). The species may also be impacted by increasing fires (A. Lees in litt. 2022).
Conservation Actions Underway
No targeted actions are known for this species.
Conservation Actions Proposed
Quantify the population size. Research the species's ecology, behaviour and subpopulation structure. Monitor the population trend.
Expand the protected area network to effectively protect key sites. Effectively manage protected areas, utilising emerging opportunities to finance protected area management with the joint aims of reducing carbon emissions and maximizing biodiversity conservation. Incentivise conservation on private lands through expanding market pressures for sound land management and preventing forest clearance on lands unsuitable for agriculture (Soares-Filho et al. 2006).
12cm, 11g. Pale grey-brown crown, weak white supercillium and white streaking on greyish ear coverts. Mantle and upperwings mid-grey. Long tail often held slightly cocked, pale grey with about 6 black cross bars along it's length. Whitish underparts. Similar spp. Previously considered conspecific with Grey-mantled Wren Odontorchilus branickii, but the latter has darker and more heavily streaked crown and face and typically has more bars along the length of the tail. Also differs in habitat and vocalisations. Voice Loud series of notes on the same pitch, slower and more separate than the trill of O. branickii. Call is a high-pitched "swee".
Text account compilers
Hermes, C., Fernando, E.
Contributors
Butchart, S., Ekstrom, J., Lees, A. & Symes, A.
Recommended citation
BirdLife International (2024) Species factsheet: Tooth-billed Wren Odontorchilus cinereus. Downloaded from
https://datazone.birdlife.org/species/factsheet/tooth-billed-wren-odontorchilus-cinereus on 23/11/2024.
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 23/11/2024.