According to an international study in which the Higher Council for Scientific Research (CSIC) has participated based on the observation of the migrations of the black kite , the survival of these migratory species is based on the ability to improve the abilities to cope with environmental conditions. adverse.
This study, published in the journal Nature , adds new data to the knowledge of migratory biology, still unknown in many respects. “The improvement in the traveling capacities of birds throughout their lives is the result of the death of individuals with the least abilities , which end up disappearing from the population.
The improvement in the skills of each of the individuals who managed to survive as a result of the accumulated experience also influences, ”explains CSIC researcher Fabrizio Sergio, from the Doñana Biological Station.
To carry out the research , miniaturized satellite transmitters have been applied to 92 specimens of the black kite (Milvus migrans), a bird of prey that can live for 27 years. The monitoring has been carried out during 364 migratory trips, which “has made it possible to verify that the ability to move between Europe (where black kites breed) and Africa (where they spend the winters) progressively improves with age, especially during the first seven years of life.
The birds that were able to improve their abilities to cope with the adverse environmental conditions of these long journeys – such as headwinds and side winds – were able to survive and reproduce . On the contrary, those specimens that did not know how to improve with age ended up dying ”, says Sergio.
Another of the conclusions of the study is that “the youngest kites, between 1 and 6 years old, were less able to cope with adverse environmental conditions than the older individuals.” The researchers also highlight that understanding how climate change and human action will affect the migration of younger specimens could be the key to predicting future environmental impacts on many threatened migratory species.
