Douglas fir Douglas-fir forest is the primary habitat of the red tree vole ("Arborimus longicaudus") and the spotted owl ("Strix occidentalis"). Home range requirements for breeding pairs of spotted owls are at least 400 ha () of old growth. Red tree voles may also be found in immature forests if Douglas-fir is a significant component. The red vole nests almost exclusively in the foliage of the trees, typically above the ground, and its diet consists chiefly of Douglas-fir needles. A parasitic plant sometimes utilizing "P. menziesii" is Douglas-fir dwarf mistletoe ("Arceuthobium douglasii"). The leaves are also used by the woolly conifer aphid
Trysting tree smooth bark. The 'Great Fraser Yew' may be as much as 700 years old and once served as the rallying point of the Clan Fraser members in times of trouble. Kelso, in the Scottish Borders has a 'trysting tree' which is connected with the annual Common Ridings. The locally famous trysting place of the 'Three Thorns of Carlinwalk', this being an old name for Castle Douglas in Dumfries and Galloway, are recorded in the Ordnance Gazetteer of Scotland. Robert Burns writes of a trysting thorn tree (see below) at the Mill of Mannoch at Coylton in South Ayrshire. A new