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 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 estimated to number c.16,000,000-36,000,000 individuals (del Hoyo et al. 1996). However the European population alone was recently estimated at 9,200,000-82,000,000 mature individuals (BirdLife International 2015), therefore, the global population is likely to be considerably larger than the current estimate.
The population trend is decreasing in North America (based on BBS/CBC data: Butcher and Niven 2007). The European population trend is unknown (BirdLife International 2015).
This species breeds on islands of the high Arctic, being found on islands in the Bering Sea, from east Baffin Island (Canada), through Greenland (to Denmark), Iceland to Spitsbergen, Bear Island and the Jan Mayen Islands (to Norway), Novaya Zemlya, Severnaya Zemlya and Franz Josef Land, Russia. It is migratory, expanding its range in winter to include the North Atlantic Ocean as far south as the United Kingdom and the north-east U.S.A. (del Hoyo et al. 1996).
This species feeds mainly on small invertebrates such as amphipods and euphausiids and on fish larvae. The precise timing of its spring arrival at breeding colonies is variable depending on locality, from late February on Franz Josef Land to early May in north-west Greenland. Immense colonies are formed on sea coasts, usually nesting in crevices in rock scree of maritime slopes and on coastal cliffs. Colonies are abandoned in August with individuals seeking more southerly waters (del Hoyo et al. 1996).
As Little Auks spend much of their life at sea, including at and below the sea surface, they are vulnerable to both oil spill events and chronic oil pollution (Fort et al. 2013). The Newfoundland area is subject to chronic oil pollution, with tens of thousands of Little Auks dying in this area annually (Wiese and Robertson 2004). Recent tracking research has indicated that important foraging grounds for the species overlap with expanding oil and gas extraction activities and shipping, which could lead to habitat degradation and species mortality (Fort et al. 2013). The Little Auk is still hunted in Thule during its short period of presence in the summer, to form the delicacy Kiviaq, now only eaten at important celebrations. It is thought that, in the 1990s, annual take in Greenland was c. 60,000 birds which, due to the global population numbering over 30 million, is not thought to cause significant declines. There is also evidence for mortality due to bycatch, however, estimates for the combined bycatch of all auk species in the Northeast Atlantic is in the thousands (Fangel et al. 2015), so this is unlikely to be causing declines.
It has been found that Little Auks’ reproductive output and body condition is unaffected by the retreat of sea-ice, due to the use of bathymetric features for foraging, meaning this species will be largely unaffected by the retreat of sea-ice in response to climate change. Further research shows Little Auks are able to switch to feeding in nutrient rich coastal glacier melt-water in cases where sea-ice is absent, maintaining chick growth but showing a 4% decrease in adult body mass (Grémillet et al. 2015). There is some dispute as to whether changing sea surface temperature will have an effect on the Little Auk. It has been found that foraging plasticity allows Little Auks to feed on the smaller and less lipid-rich copepods found in warmer water without a reduction in fledging success or adult body condition, although this is thought to be at the expense of energy expenditure on other activities (Grémillet et al. 2012). In contrast to this, Hovinen et al. (2014) found adult survival to be negatively correlated with the North Atlantic Oscillation index and local summer sea surface temperatures with a time lag of 2 and 1 years respectively, implying climate change may have a negative effect on the Little Auk population.
Conservation Actions Underway
The following information refers to the species's European range only: The species is listed under the African Eurasian Waterbird Agreement. It is one of the species considered within the Action Plan for Seabirds in Western-Nordic Areas (Nordiska Ministerrådet 2010). There are 18 marine Important Bird Areas across the European region for this species.
Conservation Actions Proposed
The following information refers to the species's European range only: Identify further important sites for this species, particularly in offshore regions and designate as marine protected areas. Identify the risks of different activities on seabirds, and locations sensitive to seabirds. Manage fisheries to ensure long term sustainability of key stocks. Establish observer schemes for bycatch and prepare national plans of action on seabird bycatch. Develop codes-of-conduct for more organised activities (e.g. tourism). Ensure that appropriate protection (national laws and international agreements) applies to new areas and times in case of changes in seabird migration routes and times.
Text account compilers
Butchart, S., Ashpole, J, Ekstrom, J., Hibble, R., Stuart, A., Martin, R., Calvert, R.
BirdLife International (2021) Species factsheet: Alle alle. Downloaded from http://www.birdlife.org on 17/04/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/04/2021.