Data Zone
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 very 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.
Population justification
In 2015, the population was estimated to number 76,000 individuals (Groves 2017; Rees et al. 2019). This roughly equates to 50,000 mature individuals.
Trend justification
The species used to be widespread across North America, before populations plummeted drastically by the early 20th century, mainly as a consequence of hunting (Rees et al. 2019). These declines are however historical and the species has since increased due to conservation action, including hunting bans, and habitat protection and restoration (Groves 2017; Rees et al. 2019; Mitchell and Eichholz 2020). The average annual growth rate since 1968 is 6.6% (Groves 2017), which roughly equates to an increase of >750% over three generations (35.1 years).
The species occurs in three main populations along the Pacific coast from Alaska to the northern U.S.A., throughout the Rocky Mountains from Yukon (Canada) to the northern U.S.A. and further inland from central to eastern North America (Rees et al. 2019; Mitchell and Eichholz 2020).
Conservation Actions Underway
The population is monitored regularly during the North American Trumpeter Swan Surveys, which commenced in 1968 and are repeated every five years since 1975 (Rees et al. 2019). The species is also covered by the Audubon Christmas Bird Count (Meehan et al. 2018). The Rocky Mountain population and Interior population are augmented by reintroductions undertaken over several decades (Rees et al. 2019). To restore populations in the wild, captive breeding has been used for many decades, and there are large captive managed populations. Reserves were created to protect the species's habitat (Rees et al. 2019). New habitat is created, e.g. by treating water to increase the production of aquatic plants, by manipulating stream flow arrangements and by reducing human disturbance (Mitchell and Eichholz 2020).
Text account compilers
Hermes, C.
Contributors
Butchart, S., Ekstrom, J., Rees, E. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Trumpeter Swan Cygnus buccinator. Downloaded from
https://datazone.birdlife.org/species/factsheet/trumpeter-swan-cygnus-buccinator on 24/12/2024.
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 24/12/2024.