Justification of Red List Category
This species, which has a very small occupied range which is severely fragmented, and declining in extent and quality, 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 as land is cleared for cattle ranching and soy production, facilitated by expansion of the road network.
Vale et al. (2007) state that there is 206 km2 of suitable habitat, with a species population density of 60 individuals / km2. This gives a population size of c.5,000 individuals, and so it is placed in the band 2,500-9,999 individuals. This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.
This species is suspected to lose 83.5-83.8% 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.
Synallaxis kollari was, until recently, known from six specimens and a small number of observations along the rio Cotingo, rio Surumu, rio Tacutu, rio Uraricoera and the upper rio Branco in north Roraima, Brazil and adjacent Guyana (Forrester 1995). Although it is locally common, it has a highly fragmented range in patches of suitable habitat which total no more than 206 km2 (Vale et al. 2007). It was long known only from records (mostly since 1956) on the rio Tacutu within 2 km of the Brazil-Guyana border (Forrester 1995, Zimmer et al. 1997, A. Whittaker in litt. 1999), but it has subsequently been recorded on the rio Surumu in 1998; the rio Cotingo in 2001 (Grosset and Minns 2002); the Ireng river near its confluence with the the Tacutu in 1993-1996 (Robbins et al. 2004); on the east bank of the rio Uraricoera (45 km north-east of Boa Vista) in 2001 (Grosset and Minns 2002); on islands in the rio Uraricoera (L. F. Silveira in litt. 2012); and on the rio Parime in 2004 (Vale et al. 2007). It has been extirpated from the type locality, and it is apparently absent from south of Fortaleza de São Joaquim on the rio Branco (Zimmer et al. 1997).
Most recent observations have been in seasonally flooded riverine forest with an understorey of dense thickets and vines (Forrester 1995, A. Whittaker in litt. 1999). The sightings along the rio Uraricoera in 2001 were from riverine thickets that were not subject to annual flooding (Grosset and Minns 2002). Suitable habitat is probably restricted to within 0.5 km2 of the rivers (Zimmer et al. 1997). It has been found 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 gallery forests within the species range are being rapidly converted into rice plantations (Vale et al. 2007). The rice plantations are concentrated on the margins of the rio Branco's main tributaries and rely heavily on fertilisers, pesticides and herbicides (Vale et al. 2007). Bird and fish die-offs have been reported near these plantations (Vale et al. 2007). The margins of the rio Tacutu, rio Surumu and rio Mau in Brazil have been completely converted to rice plantations (Vale et al. 2007); some large plantations are likewise being established in Guyana (C.J. Sharpe in litt. 2016). Burning of vegetation, such as the fires that spread through Roraima in 1999 (A. Whittaker in litt. 1999), may be another major threat. Forest loss across the species's range is likely to become extremely rapid (Soares-Filho et al. 2006, Bird et al. 2011).
Conservation Actions Underway
Rice producers were evicted from the San Marcos Indigenous Reserve, which is thought to confer some protection for the species (Vale et al. 2007).
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
Symes, A., Westrip, J., Capper, D., Mahood, S., Pople, R., Harding, M., Sharpe, C.J.
Santos, M.P., Silveira, L.F., Vale, M., Whittaker, A. & Sharpe, C J
BirdLife International (2023) Species factsheet: Synallaxis kollari. Downloaded from http://datazone.birdlife.org/species/factsheet/hoary-throated-spinetail-synallaxis-kollari on 06/06/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 06/06/2023.