Maranon Spinetail Synallaxis maranonica


Justification of Red List Category
This species, which has been extirpated from several areas and now has a very small and declining range, has been uplisted to Critically Endangered because a model of future deforestation in the Amazon basin predicts that its population will decline extremely rapidly over the next three generations basin as land is cleared for cattle ranching and soy production, facilitated by expansion of the road network.

Population justification
The population size is preliminarily estimated to fall into the band 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.

Trend justification
This species is suspected to lose 85.4% of suitable habitat within its distribution over three generations (11 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 ≥80% over three generations.

Distribution and population

Synallaxis maranonica occurs in dry portions of the Marañón drainage, north-west Peru (Cajamarca) and extreme south Ecuador (Zumba area of Zamora-Chinchipe) (Ridgely and Tudor 1994, Begazo et al. 2001). At least formerly, it was uncommon to locally fairly common in suitable habitat within its restricted range (Ridgely and Tudor 1994). It appears to have declined south of Jaen, Cajamarca (R. Webster and R. A. Rowlett in litt 1998, J. Hornbuckle in litt. 1999), but it is still locally common in some areas of disturbed forest near Tamborapa and may possibly be abundant at more pristine sites (H. Lloyd in litt. 2007).


It inhabits the undergrowth of deciduous woodland, forest and forest edge, occasionally venturing into humid forest, regenerating secondary scrub and riparian thickets. It has been recorded at 450-1,800 m (Schulenberg et al. 2007). Birds usually forage in pairs on or near the ground, but have also been recorded foraging higher up in the trees (Ridgely and Tudor 1994,  H. Lloyd in litt. 2007). Basic information on ecological requirements and population trends is lacking (Remsen and Sharpe 2014).


Much of its woodland habitat has progressively deteriorated owing to widespread and long-term cultivation of land within the Marañón drainage. The spread of oil-palm plantations, cattle-ranching and logging all seriously threaten its remaining habitat, with oil extraction a potential future problem (Dinerstein et al. 1995). It does appear to tolerate some degree of habitat disturbance, however free-ranging goats are likely to further degrade the remaining vegetation (G. Engblom in litt. 2006). Accelerating deforestation in the Amazon basin as land is cleared for cattle ranching and soy production, facilitated by expansion of the road network, is predicted to cause extremely rapid population declines (Soares-Filho et al. 2006, Bird et al. 2011).

Conservation actions

Conservation Actions Underway
None is known.

Conservation Actions Proposed
Survey for undiscovered populations and determine whether the paucity of recent records in the south of the species's range is caused by lack of observer coverage or local extinctions. Develop land management strategies and protection for forests near Tamborapa (H. Lloyd in litt. 2007). 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).


15.5 cm. Plain, grey-and-rufous spinetail. Olive-brown upperparts and shortish tail. Very uniform grey underparts, with restricted white mottling on throat and faint olivaceous tinge to flanks. Similar spp. All congeners within its range have rufous on crown and black throats. Voice Song is slow-paced kiweeu keeu, sometimes with 5-10 seconds between phrases.


Text account compilers
Isherwood, I., Capper, D., Hermes, C., Pople, R., Sharpe, C.J., Symes, A.

Webster, R., Rowlett, R., Lloyd, H., Hornbuckle, J.

Recommended citation
BirdLife International (2021) Species factsheet: Synallaxis maranonica. Downloaded from on 04/12/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from on 04/12/2021.