 This largesse notwithstanding , conditions were primitive . There was no permanent minister and when one visited he was obliged to conduct sermons in the open air , there being no church . Nor was there a mill , and leather was tanned with willow bark and dressed with sea shells due to the lack of lime . The nearby smaller island of Muck was valued for land rental the same as the whole of Rùm at this time , again indicating the poverty of agriculture on Rùm . The growing population of Rùm 's demands on the land led to the extermination of the native red deer ( Cervus elaphus ) during the latter half of the 18th century . 
