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). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not 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.
The global population is inferred to number 11 million mature individuals (Partners in Flight 2019).
The species has been undergoing a large, significant increase at an average rate of 2.1% per year between 1970 and 2017 (Partners in Flight 2019). Short-term trends suggest that the population in North America has increased by 37% over the past ten years (Pardieck et al. 2018).
Text account compilers
Butchart, S. & Ekstrom, J.
BirdLife International (2023) Species factsheet: Cistothorus palustris. Downloaded from http://datazone.birdlife.org/species/factsheet/marsh-wren-cistothorus-palustris on 29/09/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 29/09/2023.