Seasonal Movement of Wild Hogs in Big South Fork National River and Recreation Area and Great Smoky Mountains National Park

Science Center Objects

The wild hog (Sus scrofa) is an exotic invasive species that significantly impacts native resources and their populations are expanding significantly throughout the United States.  In addition, wild hogs are likely contributing to the spread of disease such as pseudorabies. National Park Service units in the Southeast that have populations of exotic wild hogs include Big South Fork National River and Recreation Area (BISO) in Tennessee and Kentucky and Great Smoky Mountains National Park (GRSM) in Tennessee and North Carolina.  NOROCK is working with GRSM and BISO managers to study seasonal movement information of wild hogs to determine how they move across the landscape. 

Project Objectives are to 1) Improve existing models and overall effectiveness of wild hog control in GRSM and 2) Provide baseline data for the development of a wild hog control strategy in BISO. 

 

A feral hog is in a trap in southeastern U.S. awaiting immobilization and GPS collar.
A feral hog is in a trap in southeastern U.S. awaiting immobilization and GPS collar. These "Judas pigs" will assist USGS scientists and partners at Big South Fork National River and Recreation Area (BISO) in Tennessee and Kentucky and Great Smoky Mountains National Park (GRSM) in Tennessee and North Carolina in tracking how wild hogs move across the landscape. (Public domain.)

Background: Despite the presence of wild hogs in BISO and GRSM for nearly 50 years, studies on seasonal movements have been limited.  Given changes in the forest ecosystem and improvements in telemetry technology (e.g., GPS radio collars) a study was needed to determine how wild hogs move across the landscape.  Seasonal movement information of wild hogs will not only improve modeling efforts, but will also be useful to management staff by helping determine specific habitat use, as well as evaluate responses of wild hog to various control/hunting efforts. 

Movement data will be examined to determine how wild hogs respond to intensive hunting pressure (e.g., do they become night active? Do the leave the area?  Do they simply bed down for a long time? Does their distribution or habitat use change in response to this pressure?).  The efficiency of keeping a telemetered sample of “Judas pigs” to assist control staff in locating hogs is also being evaluated.  This information will enable BISO to make informed management decisions related to hog hunting (public hunting is allowed five months of every year), as well as aide the park in developing an effective eradication program. 

 

Project:  NOROCK is assisting in improving the capabilities of existing models to evaluate control efforts and predict consequences for spread of pseudorabies, as well as emerging foreign animal diseases by:

  1.  Initiating a radio-telemetry project to determine movement patterns of wild hogs in GRSM and BISO including their response to control/hunting efforts.
  2.  Conducting a stable isotope analysis to determine the scope and extent of illegal releases of feral hogs near GRSM. 

Information gained from this project will significantly improve the capabilities and usefulness of the models, and provide information related to wild hog control and law enforcement efforts.  Information will also be used to revise the GRSM wild hog control guidelines and GRSM wild hog management folio, as well as the development of a wild hog control strategy and plan for BISO. 

 

Field Work:  Researchers are capturing and radio-tagging feral hogs in GRSM and BISO so that about 20 are being radio monitored at any point in time.  Data is being collected year round and will be used to estimate home range and activity patterns with the goal of predicting movement across the landscape.  Researchers are also using stable isotope analysis to determine whether the origin of hogs can be determined based on stable isotope signatures.  If so, it may be possible to estimate the proportion of animals that were recently translocated.