Colononization of Madeira was years ago

The man could have been in the Portuguese archipelago of Madeira 400 years before it was colonized by Portugal. This was revealed by the dating of ancient bones of a house mouse found in a fossil site of Ponta de São Lourenço. 

According to the study, led by the Higher Council for Scientific Research (CSIC) and published in the journal Proceedings of the Royal Society B, house mice would have arrived on the island before the year 1036, most likely transported in a boat, as the note of CSIC has recently explained. The article also suggests that the introduction of this species would have led to an ecological catastrophe. 

Until now it had documented the arrival of man-they Macaronesia Atlantic north-five archipelagos in two successive waves: 

• Aboriginal, limited to the Canary Islands for two millennia.
• Colonial, from the fourteenth century onwards, which occurred in all the islands of the archipelagos. 

According to historical data, the Portuguese took possession of Madeira officially in 1419, when colonization began. 

The research team, which also included Germans and the University of La Laguna scientists analyzed two samples of bones found in Ponta de São Lourenço. 

The small size of the first date it prevented, but the second one has been dated between 900 and 1030, which is the earliest testimony of the presence of mice in Madeira. "The current populations of house mouse Madeira show similarities in mitochondrial DNA with those of Scandinavia and northern Germany, but not with those of Portugal. Therefore, this second sample analyzed leads to think that the Vikings were led home to the island mouse. However, it is a conclusion that must be ratified with new morphological and genetic studies of fossil Ponta de São Lourenço, since to date there are no historical references to Macaronesia Vikings travel" says CSIC researcher Josep Antoni Alcover, Mediterranean Institute for Advanced Studies (CSIC mixed and the University of the Balearic Islands). 

Apart from modifying the historical data, the new dating extends the time frame in which the most significant ecological changes occurred on the island. According to investigators, the first man would have triggered the extinction of endemic bird species in the archipelago of Madeira (consisting of Madeira and Porto Santo). 

Once seated, the population of mice, which hardly differs from the current house mice, have reached a high density because of its reproductive potential and the absence of rats. Their predatory activity would have focused on the eggs and chicks of small and medium birds such as quail or rails. The bones obtained from Holocene deposits indicate that at least two thirds of the endemic birds and two non-endemic species became extinct. They would also have played a significant role in enabling the prosperity of other predators such as owls. "The introduction of the mice probably led to an ecological catastrophe, based on the extinction of endemic birds and changing the ecology of the island 400 years earlier than previously thought" CSIC researcher highlights.