Words by Jocelyn Akins

Previously we described how mitochondrial DNA collected from carnivore scats can be used in conservation. Here, we explain how nuclear DNA, which we use to identify individual wolverines, Cascade red foxes, and Canada lynx, allows us to understand how carnivore populations are faring. Nuclear DNA comes from the nucleus in the animal’s cells and each cell has one copy. For this reason, it is much harder to successfully extract from a cell unlike mitochondrial DNA, which has many copies (housed within the many mitochrondria found in each cell).

The genotyping of nuclear DNA at genetics laboratories in Montana and California allows us to produce a genetic signature for each unique carnivore. This signature is called a genotype, and when we analayze the genotypes of many individuals together, we can see how genes move across the landscapes - that is, how individuals move and reproduce across the Cascade Range. We can create a landscape genetic resistance map to understand which landscape features, such as a large river or a low-elevation valley with a large highway, restrict animal movements, and thus restrict gene flow, thereby acting as a barrier or at least a challenge preventing carnivores from finding new mates. This type of analysis is critical to identify where to put a wildlife crossing, reduce highway speeds, or restore the forest in the area.

Photo credit: Duncan Mullen

Nuclear DNA is also used to determine if a population is so small that individuals are beginning to breed with close relatives, which can negatively impact the health of individuals, and thus the chances that a population will persist over time. When populations are inbred, we start looking for ways to restore connections points across the landscape, such as safe passage ways over highways to facilitate animal movement, reconnect populations, and increase genetic diversity. We may also ask whether we should introduce individuals from elsewhere and "genetically rescue” a small, inbred population. While this is no small feat, it has been successful elsewhere including with Florida panthers!