Appalachian Laboratory

Extinction Risk of the Delmarva Fox Squirrel

An example of how increasing temporal autocorrelation can influence extinction risk in animal populations is shown at right. As you can see, as the autocorrelation increases, the number of consecutive years of poor survival (or good) increases. Multiple back-to-back years of poor survival make it very difficult for all but the largest populations to avoid extinction. Fortunately, animal populations are not so highly autocorrelated as depicted above. However, we know that weather is autocorrelated and predictions of future climate indicate that the variability will increase. Should this actually happen, many populations may be at increased extinction risk.

Our modeling results are being used by the US Fish and Wildlife Service to guide management and recovery of the DFS. Our model predictions are also being used to determine if and where population reintroductions may be feasible and how many squirrels need to be initially released to maximize the chances of success.