ALRF staff and a group of UNBC students were visiting a teaching site in a shelterwood harvest treatment in late August when someone noticed a bird nest located in a short but very branchy birch tree. The site has been actively browsed by moose ever since the 18 ha block was harvested in winter 1994/95. The browse in this area was so extensive that the moose were basically controlling the brush, making room for the planted spruce to grow in the understory.
We know from a recent pilot study at ALRF that when moose browse the new shoots off birch saplings, the tree responds by sprouting more shoots, which encourages more browsing, which promotes more shoot growth, and so on, resulting in a very unusual tree morphology or shape.
Apparently some types of nesting birds also find this moose/birch browsing and growing cycle very beneficial as well! According to Plants of Northern British Columbia (MacKinnon, Pojar & Coupe), the lichen species used to construct this nest indicate either warbler or vireo bird species.