Demographics, Diet, and Spatial Characteristics of Feral Hogs in the Chihuahuan Desert, Texas

Little is known of feral hog ecology (food habits, demography, and spatial characteristics) in the desert mountains of the Southwest.  In response to the expansion of feral hogs into the arid regions of the Chihuahuan desert, Texas, we began an investigation into feral hog ecology in the Davis Mountains of west Texas. Specifically, our objectives were to (1) describe food habits, (2) document demographic characteristics, and (3) evaluate movement patterns and habitat use of feral hogs in the Davis Mountains.

Feral hogs were radio collared, and monitored via aerial telemetry to determine survival rates, herd composition and structure, and density. Summer food habits of feral hogs were determined by collecting feral hog stomachs from April - August. Summer feral hog diet consisted mainly of herbaceous material and roots and tubers, and the diets did not differ between male and female hogs. 

We found that, in comparison to feral hog populations in environments which experience more annual rainfall, the feral hogs in the Davis Mountains occur at relatively low densities, have larger ranges, and are habitat generalists. Feral hog densities were 1.7 hogs/sq mile, and males on average had a homerange size of 12,000 acres while the average female homerange size was 8,400 acres.  Feral hogs exhibited a generalized use of habitats but preferred open-canopy, evergreen woodland. Although feral hogs occurred at relatively low densities in the Chihuahuan Desert, there is still concern over their potential to cause damage to natural resources, particularly if populations are concentrated around the limited perennial water sources.  Our results suggest that to control feral hogs in the Davis Mountains, resource managers should take a proactive approach and target riparian and open canopy evergreen woodlands.

Female feral hogs and their offspring form family groups know as sounders.  The size of sounders observed in the Davis Mountains ranged from 2-12 with an average of 6 individuals.

 

diet graph

The above graph shows the summer diet of feral hogs in the Davis Mountains.  Although their diets mainly consisted of plant material, feral hogs are omnivorous and there was evidence of them consuming both invertebrate and vertebrate species.