The Little Auk Alle alle: an ecological indicator of a changing Arctic and a model organism

The Little Auk Alle alle is a small planktivorous auk breeding colonially in the High Arctic. Owing to its large population size and bi-environmental lifestyle, resulting in the large-scale transport of matter from sea to land, the Little Auk is one of the most important components of the marine and terrestrial ecosystems in the Arctic. As a result of globalization, which facilitates access to remote areas of the Earth, a growing number of studies is being dedicated to this endemic Arctic seabird. Research has focussed primarily on the importance of the Little Auk as an ecological indicator reacting to the climatic and oceanological changes that are particularly evident in the Arctic as a result of Arctic amplification (warming is more rapid in the Arctic than in any other region on Earth). Importantly, the species is also used as a model to investigate matter and energy flow through the ecosystem, mate choice, parental care and biological rhythms. Here, we review the natural history of the Little Auk, highlighting studies with the potential to provide answers to universal questions regarding the response of seabirds to climate variability and avian reproductive behaviour, e.g. threshold of foraging flexibility in response to environmental variability, carry-over effects between the breeding and non-breeding periods, the reasons for the transition from bi- to uni-parental care, parental coordination mechanisms.