Forest Connectivity and Patterns of Genetic Structure in Northern Spotted Owls
Federal researchers used landscape genetics to evaluate the role that forest connectivity plays in determining genetic connectivity for the federally-threatened northern spotted owl.
They studied associations between genetic structure and landscape connectivity, examining genes from 339 owls. The researchers found evidence that connected habitat to facilitate owl dispersal reached a low point in the 1940s, but then improved from 1986 onward. Genetic differentiation patterns, however, were more closely associated with straight line geographic distances and habitat conditions from the 1870's. These results suggest either the genetic effects of habitat alterations such as deforestation may not yet be evident in Spotted Owls, or also possibly that forest habitat was not sufficiently fragmented to the point where owl connectivity was previously disrupted. The second hypothesis could indicate that forest management practices mandated by the Northwest Forest Plan succeeded with one of its primary goals, yet authors caution that other factors, such as competition with barred owls, can influence dispersal and possibly genetic structure in northern spotted owls.
Miller, M.P., Davis, R.J., Forsman, E.D., Mullins, T.D., Haig, S.M., 2018, Isolation by distance versus landscape resistance- understanding dominant patterns of genetic structure in Northern Spotted Owls (Strix occidentalis caurina): PLOS ONE, v. 13, no. 8, p. online, https://doi.org/10.1371/journal.pone.0201720