With the 600 years of Madeira and Porto Santo celebrations upon us, an article written in 2014 could prove that Madeira was initially discovered in 1036 AD, nearly 400 years earlier than previously thought. According to studies of fossilised house mice bones unearthed in Ponta de São Lourenço, the earliest presence of mice on the island was between 900 – 1036 AD.
On further detailed analysis, the mitochondrial DNA from the mice showed Scandinavian and north German descent and not Portuguese. In this case, the Vikings may have discovered Madeira, and inadvertently brought the rodents with them, which would have had a disastrous effect on the island’s wildlife. However, there is no historical evidence showing that the Vikings sailed to the Macaronesia (Madeira, Porto Santo, Canary Islands, Açores and Cape Verde Islands) either.
According to Josep Antoni Alcover of the Mediterranean Institute for Advanced Studies, further studies of the fossilised mouse bones are needed to build a clearer picture of how these mice were introduced to the island and where they originally came from.
info at madeira-weekly.com