On December 18 of 2020, the SUBMON team made a different sighting that is always special to see: a puffin. The sighting took place during the campaign framed in the Tramontane Dolphins project, which this year has the support of the Department of Territory and Sustainability of the Generalitat of Catalonia.

Every winter, the Catalan waters are visited by these well-known seabirds due to their characteristic appearance. Puffins are birds that can reach 20 cm in height, characteristic for their white and black coloration, short orange legs and thick triangular beak with striking colors (orange with blue/gray base and yellow lines). Their friendly and graceful appearance has made them a tourist attraction in many North Atlantic countries where they can be seen during the breeding season.

However, the presence of puffins in Mediterranean waters is not related to breeding. In this case, they come to spend the winter and during these months they will feed and rest in our waters, and then return in spring to the breeding areas located on the northernmost coasts of Europe.

The puffin is a mainly pelagic bird that, apart from the breeding season, does not usually come close to the coast and while it is in our waters it is normally found on the continental slope or further out of the continental shelf and therefore, it is not easy to observe it.

This species is found throughout the North Atlantic, from northwestern Greenland to the coast of Newfoundland (Canada) and Maine (USA) to the west, and from northwestern Russia to the Canary Islands (in winter) to the east. The reproduction period occurs in the summer months and we can find them in their breeding colonies spread along the North American and North European coasts, such as Newfoundland, Labrador and Maine on the one side, and England, Ireland, Norway and Iceland on the other, where we find 60% of the world population of puffins and the largest colony of this species today. As soon as summer ends, the puffins leave the colonies and fly out to sea where they will overwinter and will not return to land until the next breeding season.

Recent studies reveal that puffins overwinter in the waters of the North Atlantic and adjacent seas with hotspots in southern Greenland, the Labrador Sea, around Iceland and the British Isles, and confirm that a proportion of birds that breed in colonies in Wales and Ireland spend the second half of winter (from December) in the Western Mediterranean. Specifically, on the east coast of the Iberian Peninsula and the French coast, but it does not extend further east to Corsica or Sardinia. These specimens reach the Mediterranean through the Strait of Gibraltar since these birds never fly large areas of land.

But if you ever observe a puffin in winter you will see that it does not have the same appearance as in summer, since the bright orange color plates and other facial characteristics are developed in spring, during the breeding season, and when the end of the breeding season is near these coatings and appendages, such as eye ornaments and bill plates, shed in a partial molt, so that the bill appears narrower, has a less bright coloration and the base becomes darker, even black. In addition, as can be seen in the photograph of the individual observed this December, the feathers on the head and neck lose their white coloration and become darker.

Currently, the puffin is considered a Vulnerable species by the IUCN (International Union for Conservation of Nature) and its population is in decline, mainly due to the change in distribution and decrease in the abundance of its prey, due to both the anthropogenic factor as the overexploitation of fishing and changes in water temperature due to climate change. Other factors that affect their survival are the presence of terrestrial predators introduced in the hatchling colonies, marine pollution and hunting.