Urbanization and fragmentation can have significant negative effects on wildlife communities including changing behavior, altering community structure, and reducing or even extirpating populations. While some population or community changes may be relatively easy to detect, for mammalian carnivores that are difficult to monitor, it may be easy to miss even large population changes. Also, while more generalist reptiles, small mammals, or birds, may seem to persist reasonably well in the face of urbanization and fragmentation, there may be significant changes occurring in these populations that are harder to detect. For example, connectivity between populations is significantly reduced in fragmented landscapes, particularly for species that may not be effectively moving through the urban matrix.
Genetic techniques may allow us to effectively monitor populations of extremely vagile species such as mammalian carnivores, while at the same time allowing us to assess the loss of connectivity between populations of less mobile species and to determine whether this loss leads to loss of genetic variability. The NPS, FWS and other agencies require such information on population status for management actions. Understanding historical genetic integrity and the loss of this integrity due to anthropogenic change can greatly inform management actions.
We have two major objectives. First, we are using genetic fingerprinting to monitor the bobcat population in the Santa Monica Mountain Recreation area (SAMO) to ascertain whether fragmentation results in changes in individual movement patterns and gene flow. Second, we are assessing the genetic effects of habitat fragmentation for a taxonomically broad range of less vagile animals (reptiles, birds and insects). We will determine whether gene flow among populations is reduced in fragmented vs. non-fragmented conditions, and whether this reduction in gene flow has lead to a reduction in genetic diversity for small populations.
This work is supported through the USGS Natural Resources Preservation Program.
USGS Contact For This Project