The Red List of threatened species prepared by the International Union for Conservation of Nature (IUCN) establishes that the populations of puffins, Fratercula arctica , are declining in practically all the enclaves where these birds can still be found, which inhabit the Arctic regions , the North Atlantic and the western Mediterranean Sea. According to the data managed by this organization, although there are still between 12 and 14 million adult individuals, it is estimated that up to 79% of all of them could disappear over the next half century.
The problem will be especially significant in Europe, where more than 90% of them live. Their congeners of the species Fratercula cirrhata – known as tufted puffins – live in the North Pacific, barely exceed 3 million and, like their relatives, are also in decline.
IUCN experts attribute it to a combination of several factors, such as the introduction of invasive species into their habitat, pollution, the deaths caused by the nets, where they are trapped, and the lack of food that causes overfishing.
Now, a team of researchers from different US institutions, coordinated by scientists from the University of Washington, in Seattle, believe that climate change may also contribute, in part, to this latest phenomenon. In an essay published in the journal PLOS ONE , they indicate that at least this is what the study of hundreds of bodies of these birds, found on the island of San Pablo, in the Bering Sea, about 400 kilometers from Alaska suggests.
The authors point out that the specimens died of starvation , shortly after an increase in sea temperatures and a notable change in the composition of zooplankton and in the distribution of fish and invertebrates that feed on it was witnessed; these, in turn, form the basis of the puffin diet.
A blow to the ecosystems
This is not the first work to explore the relationship between the aforementioned increase in temperatures, the significant alterations that this causes in ocean ecosystems and the mass deaths of birds. In this case, as of 2014, a decrease in the ice sheets that spread through the area in winter has also been observed. This, according to these researchers, has led to a progressive decline in the populations of the species from which many predators tend to feed and the migration of others to more northern regions. All together, has contributed, so to speak, to empty the pantry of the puffins.
The experts also point out that the specimens they have examined were experiencing the shedding of some feathers, a process that requires more energy from the animals and, with it, a higher intake. For this reason, the effects of the famine would have been even worse.
From the number of corpses found in this place, scientists suspect that between 3,150 and 8,500 birds would have died as a result of this phenomenon in 2016, when they began to study it.
Reference: Unusual mortality of Tufted puffins (Fratercula cirrhata) in the eastern Bering Sea . Timothy Jones et al. PLOS ONE (2019) . DOI: doi.org/10.1371/journal.pone.0216532
Image: Nic McPhee / CC
