Previously the answer to this question was something along the lines of ‘just because’. It had been observed (correctly) that there were relatively few crannogs in the eastern half of Scotland, but there had not been any deliberate attempts to explain why this is the case. To my mind, this was problematic, but also an opportunity. This question was at the heart of my MA dissertation, and led me to several conclusions.
The first conclusion is that the present landscape of northeast Scotland has gone through an incredible transformation over the past 300 years. This transformation centred around shifting agricultural practices beginning in the 18th century, and as part of this transformation, there has been a steady trend to drain lochs and other wetlands. This drainage was done to create more arable land and to access the loch sediments for use as fertiliser. The amount of drainage can be seen through a close analysis of the Roy Military Map of Scotland (the map is an incredible achievement in itself, and a future post will discuss it in more detail). The Roy Map (1747-1755) was made just as the ‘Improvements’ were getting underway, and the map shows many more lochs and wetlands in northeast Scotland than there are now (an example here). After assessing each loch depicted on the Roy Map, I found that over 70% had been drained or significantly lowered. When looking at lochs below 200m above sea level (where most crannogs can be found), that percentage creeps up close to 90%. The landscape of northeast Scotland is far drier now, than it was 300 years ago.
The impact on crannogs in the region was likely to have been similarly dramatic (up to 90% fewer crannog sites!). Crucially, this is where the timing of all this loch drainage comes into play. Most of the drainage that took place in northeast Scotland, occurred during the 18th century and the first few decades of the 19th century. This was before widespread interest in antiquities and the past (particularly the past relating to Britain, as opposed to Ancient Rome or Greece). It is safe to assume then that most crannogs uncovered through drainage in the area were simply removed. But there is some reason to be hopeful for northeast crannogs, as upon further investigation of the areas of drainage, there appears to be handful of sites recorded within these former lochs that bear resemblances to a crannog. For various reasons they have not been recorded as crannogs, but they definitely deserve to be re-assessed in light of their likely former situation within a loch, and some of them may turn out to be crannogs.
So why are there so few crannogs in northeast Scotland? – the answer is mostly drainage. It is reasonable to assume that owing to naturally fewer lochs in the region prior to drainage, there have always been fewer crannogs, but the relatively early and intense levels of drainage in the northeast has vastly exacerbated the disparity in numbers. This significantly changes the distribution of crannogs throughout the country. Exploring how this impacts our understanding of crannogs as a site type in Scotland is forming an integral part of my PhD research and should influence how research on crannogs is viewed going forward.