Nesting habitat may sometimes develop earlier in younger coastal forests with a high proportion of western hemlock. Douglas-fir dominated forests develop murrelet habitat characteristics at an older age. Forests with residual trees or other suitable stand attributes may be the products of windstorms, fire, local microclimates such as high humidity zones, previous logging operations that did not remove all trees, or high site productivity for regrowth of historic clearcuts. These stands usually exhibit a broad range of interior conditions often including snags, decaying down material, and moss. Platforms may be the top of a large branch, forked limb, dwarf mistletoe infection, witches broom, deformities, overgrown broken tops, or other structure large enough to provide a useable surface for a nesting adult.
Canopy cover directly over nests provides protection from predators and weather.
Some of those forests may indeed have large size classes of fast growing trees on high quality sites, but lack the large branches and irregular crown structures for platforms, cover, and moss potential. The process outlined below displays two alternative methods to determine whether or not there are enough platforms present in a stand to trigger murrelet surveys. The Field Sampling Method employs sampling of candidate stands selected using local knowledge, aerial photographs and inventory data. The Inventory Model Method utilizes the results of a platform model developed to query an inventory system and predict the likelihood of platforms. Field Sampling Methods Select stands that meet murrelet forest stand characteristics and field review to confirm the findings.