Informing wildlife habitat conservation just became a little easier, thanks to new methods for combining local research with the Forest Service Forest Inventory and Analysis (FIA) Program’s vast database of forest metrics. A Northern Research Station scientist and his partners developed a novel approach to helping the Minnesota Department of Natural Resources better understand potential wood duck habitat in Northern Minnesota.

Tree cavities provide nesting habitat for wood ducks, a species prized by both waterfowl hunters and wildlife watchers. But nesting duck hens won’t settle for any tree hole; cavity size, height, and condition need to be just right. Artificial nest boxes provide such conditions at some local sites, but natural cavities in forest trees support a majority of the wood duck population. Forest managers need to know how many suitable nesting cavities are available, and how those numbers are changing over time. But counting cavities over millions of acres of forest is an impossible task. Wildlife researchers from the Minnesota Department of Natural Resources (MN DNR) recently reported that the probability of suitable nest cavity occurrence is based on three tree characteristics: species, size, and health status. These same tree attributes are measured on every FIA sample plot. Researchers from the Northern Research Station FIA program and the MN DNR teamed up to develop new statistical methods for extrapolating local research findings to strategic scales. They found that the abundance of potentially suitable wood duck nesting cavities increased during recent decades in northern Minnesota, exceeding prior projections. The methodology can be used to assess trends across the range of wood ducks and other cavity nesting species, making the research good news for wood ducks and the forest owners who manage their habitats in Minnesota, and even better news for wildlife managers who need tools that allow for accurate assessments of habitat.