Goals and Objectives:

• Quantify the extent of deer population genetic structure across Iowa, and identify relationships between landscape features and genetic structure.
• Characterize levels and patterns of genetic diversity in deer in Iowa and other Midwest states.

Progress:

We received several thousand deer tissue samples collected for the Iowa Department of Natural Resource’s CWD surveillance efforts. In addition, we obtained samples from several Midwest states. Deer selected for the project were genotyped at 10 microsatellite markers and the control region of mitochondrial DNA (mtDNA) was sequenced.

We found that white-tailed deer exhibited relatively weak genetic structure across Iowa. We detected very small associations between genetic structure and natural (i.e., amount of row crop agriculture, ecoregion) and anthropogenic (i.e., interstate highways) features of the Iowa landscape suggesting that they likely have minimal effects on deer movement.

We sequenced mtDNA of deer from 11 Midwest states, including Iowa. Deer in all states exhibited high levels of mtDNA diversity. We identified 15 different quite distantly related haplotype groups across the Midwest, the most frequent of which occurred in almost all states. In Iowa and the states immediately surrounding it, two haplotype groups predominated.

Conclusions and Recommendations:

Our findings suggest that, for the deer population in Iowa, landscape features likely have minimal effects on dispersal. Consistent with conclusions drawn in other investigations documenting weak genetic structure in deer in agricultural areas of the Midwest, it appears that the natural (deer-mediated) spread of disease will largely only be limited by the dispersal distance of deer.

Regionally, standing levels of mtDNA diversity are likely the result of the complex history of deer in the Midwest. Specifically, following a history of overharvest and local extirpation, relatively recent recolonization coupled with the high mobility of deer and their ability to adapt to a diversity of habitat types likely facilitated extensive spatial mixing of the diverse and highly differentiated lineages we observed across the 11 states.

Funding Organization: Iowa Department of Natural Resources (IDNR)

Duration: 06/01/2011 to 12/31/2015