Data Zone
Justification of Red List category
This species has a very small population, which is restricted to gallery forests along the upper rio Branco and its tributaries. Very rapid future declines are suspected due to proposed hydroelectric dams that could destroy a significant extent of remaining habitat, on top of ongoing rapid rates of forest cover loss in this highly limited forest type. The remaining population is considered to already have been divided by habitat loss into increasingly separate and very small subpopulations. The species is therefore listed as Endangered.
Population justification
Extensive playback surveys along the rivers in the Guyanese part of the range found a density of 55 mature individuals/km2 (South Rupununi Conservation Society 2021). Combining this with existing population estimates made by Vale et al. (2007) in the remainder of the species' range in Brazil (where density [60 mature individuals/km2] and occupancy estimates were broadly similar), a global population of c.1,900-8,100 mature individuals was extrapolated (South Rupununi Conservation Society 2021, B. O'Shea in litt. 2022). However, given the data used for estimating the habitat extent and population size in Brazil are 20 years old, an updated assessment is urgently required (South Rupununi Conservation Society 2021, B. O'Shea in litt. 2024). With the expectation that population will have declined, but uncertainty increased, the lower bound of the estimate is reduced and the population size estimated to lie within a range of 1,200-8,100 mature individuals.
The population may have previously been panmictic, and the species is monotypic, but the loss of habitat has divided the range into at least five separate areas that are believed to exceed regular dispersal distance in the species (GBIF.org 2023). Precautionarily the largest subpopulation is placed in a band of between 240-2,000 mature individuals.
Trend justification
During surveys along rivers in Guyana, the species was absent from large tracts of seemingly suitable habitat where it had been observed previously (Vale et al. 2007, South Rupununi Conservation Society 2021, B. O'Shea in litt. 2022). It has been hypothesised that the population decline is caused by habitat loss as well as fires degrading and fragmenting habitat, leading to increasing isolation between populations (B. O'Shea in litt. 2022).
Over the past ten years, 22% of tree cover has been lost within the range; since 2017 this has been increasing such that the average rate over the past five years is now equivalent to 30% over ten years between 2017 and 2027 (Global Forest Watch 2023, using Hansen et al. [2013] data and methods disclosed therein). These values however do not account for additional habitat degradation and fragmentation. The species may be disproportionately affected due to its strict habitat requirements, as its riverine habitat is easily accessible and thus highly susceptible to forest loss and degradation. To illustrate this, comparable surveys between 2004 and 2021 indicated a range contraction exceeding 50 linear kilometers along the Ireng (Maú) River (B. O'Shea in litt. 2024). Moreover, large parts of the range lie within the footprint of the proposed Bem Querer hydroelectric dam on rio Cotingo (Naka et al. 2020, Aleixo et al. 2023). This is scheduled for completion in 2031 and will flood a significant proportion of the species' habitat, with no prospect for the creation of new suitable areas. Tentatively, rates of population decline are suspected to have been within the band 30-49% over the past ten years, to accelerate but remain within this band in the ten years from 2017 to 2027 and subsequently accelerate to exceed 50% in the ten years from 2025 to 2035.
Synallaxis kollari occurs on the upper rio Branco, on rio Uraricoera, rio Tacutu, rio Cotingo, rio Parimé and Ireng river in north Roraima, Brazil, and adjacent Guyana. It is restricted to gallery forest within the floodplain of the rivers, and consequently has a limited range and an estimated area of occupancy of between 1,200 and 2,400 km2, based on a 2x2 km grid across the mapped range. This lies within a small extent of occurrence of 12,500 km2. However, the AOO is inferred to be undergoing a continuing decline based on the rapid rate of forest cover loss within this range (Global Forest Watch 2023) and the observation from repeated surveys of the contraction by over 50 linear kilometres of the range along the Ireng (Maú) river between 2004-2021 (B. O'Shea in litt. 2024). Patchy occurrence may mean that actually considerably less than the assumed half of the potential AOO is occupied. With the threat posed by dam construction for hydroelectric power coupled with greatly changed fire impacts and ongoing rapid forest cover loss due to clearance for agriculture and logging, a continuing decline in the area, extent and quality of habitat is inferred to be taking place. In addition, the number of locations is considered to be small, between 6-10 and the impacts described above are inferred to indicate that there is also a continuing decline in this value.
The species occurs in seasonally flooded gallery forest with an understorey of dense thickets and vines along the river edge, within c. 1,500 m from the river (Forrester 1995, A. Whittaker in litt. 1999, South Rupununi Conservation Society 2021). It has also been seen in fairly disturbed gallery forest (L. Silveira in litt. 2007). A bird was seen entering an apparently incomplete nest in July (Grosset and Minns 2002).
The species is threatened by accelerating deforestation within its range as land is cleared for the expansion of small-scale agriculture and rice cultivations, as well as selective logging in gallery forests (Vale et al. 2007, Aleixo et al. 2023). Burning of habitat is a significant threat, such as the fires that spread through Roraima in 1999 (A. Whittaker in litt. 1999) and again in 2024 (B. O'Shea in litt. 2024). It is hypothesised that habitat degradation through fires caused population declines in Guyana (B. O'Shea in litt. 2022). Moreover, large parts of the range are likely to be affected by the planned Bem Querer hydroelectric dam on the rio Cotingo (Naka et al. 2020, Aleixo et al. 2023), scheduled for completion by 2031 (EPE 2024). Three additional small dams have also been proposed along the Mucajai River within the range of the species (Fearnside 2020).
Conservation Actions Underway
The species is included in a multi-species action plan for the conservation of birds of Amazônia, Brazil (ICMBio 2015). It is listed as Vulnerable at the national level in Brazil (Aleixo et al. 2023).
Conservation Actions Proposed
Research the species' ecology and response to habitat fragmentation, and assess its population structure. Research actions for the conservation of the species and its habitat. Monitor the population trend.
Expand the protected area network to effectively protect key sites. Protect river-island habitat and adjacent gallery forest on the mainland. Effectively manage protected areas, utilising emerging opportunities to finance protected area management with the joint aims of reducing carbon emissions and maximizing biodiversity conservation. Restore degraded areas to facilitate movement and gene flow. Raise awareness for the species with the aim of reducing pressures on its habitat. Mitigate the impacts of the planned hydroelectric dam on the species' habitat. Establish and expand ecotourism activities in the area. 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).
15.5 cm. Bright rufous spinetail with distinctive head pattern. Grey-brown crown. Rufous postocular stripe. Grey cheeks. White malar stripe. White throat speckled black. White belly. Voice Song consists of pairs of short notes at one-second intervals, the second note slightly higher pitched.
Text account compilers
Hermes, C., Martin, R., Vine, J.
Contributors
Capper, D., Harding, M., Mahood, S., O'Shea, B., Pople, R., Santos, M.P., Sharpe, C.J., Sharpe, C J, Silveira, L.F., Symes, A., Vale, M., Westrip, J.R.S. & Whittaker, A.
Recommended citation
BirdLife International (2024) Species factsheet: Hoary-throated Spinetail Synallaxis kollari. Downloaded from
https://datazone.birdlife.org/species/factsheet/hoary-throated-spinetail-synallaxis-kollari 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.