 The nature of agricultural production was determined by the land and climate . The cold and wet climate meant that more oats and barley were grown than corn . The evidence of bones indicates that cattle were by far the most important domesticated animal , followed by pigs , sheep and goats , while domesticated fowl were very rare . Bone evidence indicates that there was a significant growth in the fish trade around 1000 . This increased marine exploitation of the Highlands and Islands may have been as a result of the arrival of Scandinavian settlers in this period . 
