Monday, March 18, 2013

Riparian Areas and Wild Pigs

(Healthy riparian area with lush early spring vegetation)

Riparian areas are found between upland areas and streams or rivers. They serve a vital role in the function of a healthy watershed. Riparian areas help to slow the flow of flood water which slows erosion and increases water infiltration. These areas also increase sediment and nutrient filtration along with protecting the stability of stream and river banks. The vegetation found in riparian areas is a major contributor of nutrients and energy into the aquatic community within the stream or river. The structure and diversity of plant species in riparian areas also provide excellent habitat for wildlife species.

(Wild pig cooling down along a stream bank)

Wild pigs are a highly destructive invasive exotic species which threaten the structure and function of riparian areas. These dense, low lying areas allow wild pigs to move through the habitat unseen in the thick vegetative cover. While using these riparian areas as travel corridors, wild pigs opportunistically feed on the roots and mast of the plants found within the area. Wild pigs consume mast such as acorns directly off the ground and access underground food items by rooting in the soil. Overtime these feeding strategies can cause a shift in the riparian plant community by inhibiting the reproduction of some native plant species and providing optimal conditions for exotic species to colonize within the disturbed soils. During the warmer months wild pigs wallow along the stream banks to help regulate their body temperature since they lack sweat glands. Wallowing by wild pigs affects bank stability along with increasing the amount of sediment within the surrounding water.    

(Wild pig wallow along a stream bank)

Besides affecting the physical properties of riparian areas, wild pigs also alter the chemical and bacterial properties of the water found along the edge of riparian areas. Wild pigs serve as a non-point source of water pollution due to their fecal deposition in and around the water body. A variety of pollution sources including wild pigs have been cited as contributors to elevated bacteria levels in waters that have been listed as impaired by the Texas Commission on Environmental Quality.
Reducing wild pig populations would greatly benefit riparian areas across the state. Currently there are four legal methods for reducing wild pig populations in Texas. They include: trapping, shooting, snaring and the use of catch dogs. None of these methods are effective by themselves, but when used strategically in conjunction with one another they can be quite effective at reducing wild pig populations.
(Wild pigs captured in a corral trap)
The hyper-linked resource document below will provide you with quick access to many of our online feral hog resources including publications, fact sheets and videos.


If you would like to find out more about wild pigs or their management please feel free to contact Mark Tyson at mark.tyson@ag.tamu.edu (979) 845-4698 or Dan Gaskins at dan.gaskins@tamu.edu (254) 248-0562. We would be happy to offer watershed-based educational trainings to your organization or group. We also offer site visits for landowners to assess wild pig damage and formulate a population reduction strategy specific to the property. These services are provided free of charge through a Clean Water Act §319(h) non-point source grant from the Texas State Soil and Water Conservation Board and the U.S. Environmental Protection Agency.