USGS
USGS Western Ecological Research Center

Use of Genetic Techniques to Evaluate the Impacts of Urbanization and Fragmentation on Wildlife, from Wide-ranging to Sedentary Species


ROBERT N. FISHER¹, SETH RILEY², KATHLEEN SEMPLE DELANEY³, AMY VANDERGAST¹, TOM SMITH³, AND ROBERT K. WAYNE³
1 USGS, Western Ecological Research Center, San Diego Field Station
2 National Park Service, Santa Monica Mountains National Recreation Area
3 Department of Ecology and Evolutionary Biology, University of California, Los Angeles


Bobcat, Felis rufus

Project Overview

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.

Products

Vandergast, A. G., E. A. Lewallen, J. Deas, A. J. Bohonak, D. B. Weissman, and R. N. Fisher. in press. Loss of genetic connectivity and diversity in a southern California endemic Jerusalem cricket (Orthoptera: Stenopelmatidae: Stenopelmatus “santa monica”) in urban microreserves. Journal of Insect Conservation.
Side-blotch lizard, Uta stansburianaWestern skink, Eumeces skiltonianus
Western fence lizard, Sceloporus occidentalis
Wrentit, Chamaea fasciataStriped Jerusalem cricket, Stenopelmatus fuscus
Study animals from top:
1) Bobcat, Felis rufus
2) Side-blotch lizard, Uta stansburiana 3) Western skink, Eumeces skiltonianus
4) Western fence lizard, Sceloporus occidentalis
5) Wrentit, Chamaea fasciata 6) Striped Jerusalem cricket, Stenopelmatus fuscus

Back to SDFS Genetics Home


-- WERC Home -- Who We Are -- Where We Are -- What We Do -- What's New -- Outreach -- Contact Us -- Search --

USGS Privacy Policy, Disclaimer , Accessibility
Comments to: webmaster@werc.usgs.gov
URL: http://www.werc.usgs.gov/sandiego/SAMOPage.html
Last update: June 14, 2007