Irish badgers have previously been the subject of several genetic studies which compared their heritage to those of badgers from other European countries
In a new study, just published the journal Royal Society Open Science1, scientists from the Agrifood and Biosciences Institute in Northern Ireland, working with colleagues from the Department of Agriculture Food and the Marine and Waterford Institute of Technology in the Republic of Ireland, assembled a larger, island-wide set of 545 badger samples.
Collaborators at the Universities of Glasgow and Exeter and the UK Animal and Plant Health Agency provided a further 91 samples from British badgers.
How badgers came to Ireland
Their population genetic analyses have revealed that badgers with British genetic heritage are localised in north-eastern and south-eastern counties in Ireland and that human-aided import of badgers from Britain, around 700 years ago, is the most probable explanation.
Although anecdotal, it is notable that humans from these same regions in Ireland also exhibit genetic and genealogical links to Britain, an observation thought to result from the Plantations of Ireland that occurred in the 13th and 16th centuries.
These findings improve our knowledge of how Ireland’s modern mammal populations have been formed and specifically enhance our appreciation of the population structure of badgers in Ireland.
Links to WIT
Dr Denise O'Meara, Lecturer in Molecular Biology at WIT is co-author of the publication. O'Meara contributed samples and the study builds on an earlier study she led in 2012 related to the origins of Irish badgers, and this new study has added further to our knowledge of the history of badgers in Ireland.
She says "This new study has shown that while some Irish badgers have been here for thousands of years with genetic similarity to badgers in Scandinavia and Iberia, others retain a more recent genetic footprint to Britain, and were likely introduced here during the plantations. It is interesting from the perspective that the genetic legacy of Irish mammals has parallels to the genetic history of Irish people," she says.
Mammals in Ireland
The island of Ireland has fewer mammal species than Britain and continental European neighbours, a fact related to the island’s deep geological history. Ireland became an island around 15,000 years ago, at a time when glaciers were retreating from northern Europe, Permitting recolonization by animals that had retreated to more temperate, southern climates at the height of the last ice age.
Consequently, natural colonisation routes for animals into Ireland were barred for all but those species that could fly. As a result, how Ireland came to acquire the fauna it possesses in modern times, is one of the great puzzles of modern biology. Much effort has been expended in the field of genetics to attempt to discover from where extant Irish animals came and how and when they arrived.
The Irish badger
Irish badgers have previously been the subject of several genetic studies which compared their heritage to those of badgers from other European countries. These revealed that Irish badgers had a mixed genetic profile – sharing similarities with animals from Britain and Scandinavia and suggesting they may have been moved from those territories into Ireland by human agency.
However, these studies were based on small numbers of animals from only a few Irish locals. The extent of the influence of British animals on the Irish population, and the timing and mechanism of any potential import events remained unclear.