Climate change affects many species and alters a large part of their habitats. Even the life of migratory birds is modified by the increase in temperatures and associated climatic changes.
Some species, however, show exceptional adaptive capacity (resilience). This is the case of the Short-billed Goose (scientific name Anser brachyrhynchus), an Arctic goose that is modifying its migratory route by up to 1,000 km to better adapt to the new conditions caused by climate change.
The variation of course to the breeding areas has not only been observed in a particular group of animals, but seems to be being adopted by a large part of the species, in a possible new case of cultural transmission (social learning), according to a study led by experts from the Department of Ecoscience at the University of Aahus (Denmark), whose results have been published in the journal Current Biology.
Among the conclusions of this research is the fact that, possibly thanks to this adaptation to climate change, the population of short-billed goose has increased in the last decade by around 4,000 individuals.
"It is extremely fascinating to witness such a rapid evolution of new breeding sites and migratory routes by a species of bird that is considered to have highly fixed behavior," explains Jesper Madsen, co-author of the study and professor at Aarhus University. "It gives some hope for 'ecological rescue' in times of very radical environmental changes due to climate change and, more broadly, global change; this is very rare to observe; the speed of development is staggering," says this expert in a Note released by your university.
Madsen's team has been studying the population of these geese in Svalbard, Norway, for more than 35 years. They have kept a check on their population size and demographic variables, using a systematic program of marking and resighting. About 20 years ago, reports began of geese of this species migrating to Sweden and Finland, which were confirmed as members of the Svalbard population.
To learn more, members of the team traveled to Oulu, Finland, in the spring of 2018 and 2019 to observe the birds and mark some of them with tracking equipment, so that the migratory route and origin of the birds could be detailed. the individuals.
"It was a real surprise to see that half of the individuals tagged in Oulu migrated northeast to Novaya Zemlya in northern Russia," says Madsen. "From the tagging information, we were not only able to track their new course, but also got indications that the females were breeding there. This site is about 1,000 kilometers east of the Svalbard breeding grounds."
"It was also great to observe that geese from the traditional flyway appeared on the new route and seemed to have changed. So social learning and tracking of individuals from the new route has been an important phenomenon, which also explains how this development could be so fast," says Jesper Madsen.
Over the past 10-15 years, the population of these geese has grown due to breeding success and high survival rates, quite possibly as a result of adopting the new migratory route, the new study results indicate.
The new route has some disadvantages, for example it is longer, but the researchers suspect that the benefits of the new route and the conditions in the nesting area outweigh any drawbacks. The findings in geese show the importance of social learning in a changing planet, Madsen notes, especially in social animals, including birds, but perhaps also in ungulates, wolves and whales.
"At this time, when climate change and other human activities threaten many species, especially those in the Arctic, social learning may be a behavior that can provide advantages to avoid some negative impacts, at least in the short term," explains Jesper. Madsen.
