Justification of Red List category
This species has a very 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, but this species is described as 'fairly common' (Stotz et al. 1996).
Trend justification
There are no data on the population trend. The species has however disappeared from large areas in Paraguay, likely as a consequence of forest loss and degradation (per Narosky and Yzurieta 2006, Global Forest Watch 2023, B. Phalan in litt. 2023). In Misiones, Argentina, the species is described as locally stable or increasing in undisturbed forests (M. Lammertink in litt. 2023); this area holds large tracts of seemingly pristine habitat (Global Forest Watch 2023).
Overall, declines are likely to be occurring as populations are affected by habitat loss and degradation and are becoming increasingly fragmented.Within the range, 10-12% of tree cover is lost over ten years (Global Forest Watch 2023, using Hansen et al. [2013] data and methods disclosed therein). While the species may also occur in bushes along forest edge it is overall considered forest-dependent; consequently, the rate of population decline may be roughly equivalent to the rate of tree cover loss. The population decline is therefore here placed in the band 1-19% over ten years.
Polioptila lactea occurs in the lowland Atlantic Forest of south-east Brazil (Paraná, Santa Catarina, Rio Grande do Sul), north-east Argentina (Misiones, Corrientes) and east Paraguay (Alto Paraná and Itapúa).
This species inhabits the canopy and sub-canopy of lowland primary forest and woodland, as well as in bushy and forest edge habitat (Lowen et al. 1996, Atwood and Lerman 2020). Its ecology is poorly known.
Agricultural conversion and deforestation for mining and plantation production are historically important factors in the destruction of its habitats (Dinerstein et al. 1995, Fearnside 1996). Current key threats include agricultural expansion, mainly for cattle pastures and cropland (especially soy bean and maize), urbanisation and associated road-building (Dinerstein et al. 1995, Fearnside 1996, B. Phalan in litt. 2023).
Conservation Actions Underway
It is listed as Vulnerable at the national level in Argentina (MAyDS and AA 2017).
Conservation Actions Proposed
Quantify the population size. Conduct repeated surveys of known sites to determine rates of population decline and range contraction. Research the species ecology, behaviour and population structure. Monitor the population trend. Monitor rates of habitat loss. Rigorously protect remaining tracts of lowland Atlantic forest.
Text account compilers
Hermes, C.
Contributors
Butchart, S., Chebez, J.C., Gilroy, J., Lammertink, M., Mazar Barnett, J., Phalan, B. & Sharpe, C.J.
Recommended citation
BirdLife International (2024) Species factsheet: Creamy-bellied Gnatcatcher Polioptila lactea. Downloaded from
https://datazone.birdlife.org/species/factsheet/creamy-bellied-gnatcatcher-polioptila-lactea on 23/12/2024.
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 23/12/2024.