In a statement, CIBIO-Azores clarifies that the study reconstructed the conditions in which the Azores were inhabited for the first time and the impact that human presence had on the archipelago's ecosystems.

One of the main conclusions of the investigation, published in the journal PNAS, is that the first evidence of human presence on the islands was detected 700 before the arrival of the Portuguese in the 15th century, namely on the island of Santa Maria in 1427 and on the islands of Corvo and Flores in 1452.

The study also suggests, based on different simulations to determine weather conditions, that the first settlers of the archipelago were "probably" from northern Europe and that they found "favorable weather conditions to navigate towards the Azores at the end of the High Middle Ages , due to the predominance of the northeasterly winds and the weakening of the western ones”.

“The work now published records the arrival of the first settlers to the islands at the end of the High Middle Ages”, stresses CIBIO – Azores, adding that the investigation contradicts the consensus that the archipelago had never been inhabited until the arrival of the Portuguese.

Quoted in the statement, Pedro Raposeiro, a researcher at the Azorean center and the first author of the article, stresses that the investigation “demonstrates the importance of promoting multidisciplinary studies between the natural sciences and the human sciences” so that there is “a broader vision of what really happened in the past".

The researchers analyzed and dated, using geological, chemical, physical and biological techniques, five soundings of sediments recovered from the bottom of lakes on the islands of São Miguel, Pico, Terceira, Flores and Corvo.

“They detected in the lake sediments the presence of sterols, a very abundant fraction of the organic matter in the feces of mammals, and coprophilic bottoms, which are interpreted as indicators of human activity”, explains the center.

Also quoted in the statement, Timothy Shanahang, a researcher at the University of Texas (United States of America), clarifies that the intestines of mammals produce “in abundance fecal sterols and stanols that are well preserved in lake sediments and are a unique and unequivocal indicator of the presence of large mammals in certain periods of the past”.

“Furthermore, the compounds produced by the human intestine and by cattle are different, which allows us to distinguish them,” he says.

Santiago Giralt, one of the main authors of the article, adds that, due to their geographical position, the islands of the Azores “were not inhabited by large mammals” and that the appearance of “coprostanol in sediments can be attributed to the presence of humans and stigmastanol to ruminants such as cows, goats or sheep”.

Based on the study of pollen, fossil plant fragments and coal residues present in the sediments, the investigation also characterized the impact of the first human occupations on the islands' ecosystems, which led to “profound ecological and environmental changes”.

“Although historical sources describe the Azores as densely forested and untouched, this work highlights the discrepancy that exists between the fossil records and the historical records that most often serve as a reference to identify pristine ecosystems”, says Pedro Raposeiro.

In addition to researchers from the center of the University of the Azores, the study in Portugal had the collaboration of the Portuguese Institute of the Sea and Atmosphere (IPMA), the Dom Luiz Institute, the University of Lisbon, and the University of Évora.

Experts from Geosciences Barcelona (GEO3BCN-CSIC), the Institute of Science and Technology of the Autonomous University of Barcelona, ​​the Center for Ecological Research and Forestry Applications (CREAF), the Institute of Marine Research (IIM-CSIC) of the National Museum of Natural Sciences (MNCN-CSIC), University of A Coruña (UC), University of Barcelona (UB), University of Texas, Brown University of the United States of America, NIOZ (Netherlands), University Amsterdam (Netherlands), the University of Bern (Switzerland) and the Edith Cowan University (Australia).