Data Zone
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). 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 estimated at 90,000-120,000 mature individuals, 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
MNRE (2021) indicate that the total population is c.45,000 breeding pairs (c.90,000 mature individuals), which is broadly consistent with spring counts in Alaska typically finding 60,000-80,000 birds, not all of which will be mature individuals (Schmutz et al. 2020). Wetlands International (2022), citing Dooley et al. (2016) for justification, suggest a global population of 158,000 birds, although it is unclear what percentage of these are mature individuals. Overall, the population is estimated at 90,000-120,000 mature individuals to account for these uncertainties, as well as annual variation (see USFWS 2022).
Trend justification
In the USA, where approximately 70% of the population breeds, the trend is thought to have been declining between 1964 and 1981. Between 1981 and 2015, population trends from spring aerial staging surveys were essentially stable (CAFF 2018), while summer aerial surveys from the Yukon-Kuskokwim Delta between 1985 and 2014 showed an annualised growth rate of 2.9% per year. In Russia, numbers of moulting geese in southern Chukotka also showed an increased since the mid-1990s (CAFF 2018). Such trends (using largely the same, though more contemporary, data) are repeated in most recent sources (e.g. Figure 13, in USFWS 2022). The principal threat to this species, hunting, is unlikely to cause substantial declines in the future, with offtake carefully managed by the USFWS, with a closure of all hunting if/when numbers fall below a set three-year running average and strict enforcement of harvest restrictions (Schmutz et al. 2020, USFWS 2022). Although listed as Vulnerable in the national red list of Russia, there too the population is reportedly increasing (CAFF 2018, MNRE 2021). Globally therefore, the global population trend is set to increasing, with no immediate indication this is at risk of changing in the near future.
Anser canagicus is restricted to the Bering Sea, breeding in Arctic and subarctic Alaska, USA and extreme north-east coastal Russia, and wintering principally along ice-free coasts of the Aleutian Islands and, in smaller numbers, along the Alaska Peninsula, occasionally, as a vagrant, to Canada and in some years even as far south as California (Petersen et al. 1994). Some Russian breeding birds migrate across the Bering Sea to the Alaska Peninsula and further to the Aleutian islands, joining Alaskan breeding birds there. Others winter on the Commander Islands and along the eastern coast of Kamchatka (MNRE 2021).
In the breeding season, it breeds on coastal salt marsh habitats with tidal influences; on migration and in winter it typically inhabits the intertidal zone (Schmutz et al. 2020).
In Russia, threats identified (MNRE 2021) include predation by Arctic Foxes Vulpes lagopus in years with low numbers of lemmings; disturbance by humans July-August at moulting sites; and in some areas illegal hunting. In Alaska, these threats are also noted (Schmutz et al. 2020), as is pesticides and the degradation of habitat. However, in both countries the population size of this species is estimated to be increasing; thus, while all are plausible and potentially acting threats, none are considered likely to be causing population declines. Climate change has been noted as a potential future threat, with Zöckler and Lysenko (2000) suggesting that 54% of suitable habitat for this species could be lost by 2070. In the absence of evidence that this is yet impacting the population negatively, this is considered a plausible future threat.
Conservation Actions Underway
In Alaska, hunting is strictly controlled by the US Government, with quotas (between 500 and 1,000) determined by three-year averages (see USFWS 2022, Alaska Department of Fish and Game 2022). In both the US and Russia, it is protected through much of its range (MNRE 2021) and will likely benefit from proposed protected areas.
Conservation Actions Proposed
Continue to monitor the population at selected sites and ensure that hunting remains sustainable.
Text account compilers
Berryman, A.
Contributors
Benstead, P., Mahood, S., Pilgrim, J. & Taylor, J.
Recommended citation
BirdLife International (2024) Species factsheet: Emperor Goose Anser canagicus. Downloaded from
https://datazone.birdlife.org/species/factsheet/emperor-goose-anser-canagicus 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.