Impact of baiting on feral swine behavior in the presence of culling activities

Abstract

We studied the effects of baiting on feral swine (Sus scrofa) movements and corresponding likelihood of disease spread under real and simulated culling pressure. Our objectives were to determine the proportion of feral swine that used the bait station site, and if baiting of feral swine altered areas of utilization, distances from location centroids to treatment location (control or bait station), and movement rates by survivors during culling activities. We hypothesized that the bait station would increase the sedentary nature of feral swine, thus reducing the potential for dispersal and hence disease dispersal. Our experiment was conducted between February and May 2011 on the Rob and Bessie Welder Wildlife Foundation (WWF) in San Patricio County, Texas. We trapped 83 feral swine and placed GPS collars on 21 animals. We established and maintained a centralized bait station on one side of the WWF from 13 March to 27 April. We conducted population-wide culling activities, including trapping, controlled shooting, drive shooting, and aerial gunning, from 3 to 27 April and removed 143 feral swine (4.6feral swine/km(2)). Areas of utilization did not differ between treatments (control or bait station). However, we found location centroids of bait station site feral swine to be closer to the treatment location than those of control site animals and daily movement rates of bait station site feral swine to be 39% greater than movement rates of control site animals. Based on our observation that only 62% of feral swine trapped in proximity to the bait station used it, we cannot recommend baiting as an alternative to fences for containing animals during culling activities. However, there is value in using bait stations to describe patterns of feral swine movements, facilitate observation, and improve efficacy when conducting removals.

Effects of simulated removal activities on movements and space use of feral swine

“…Although this removal activity was only applied once to collared feral swine, these findings support our first removal activity results. Similarly, population-wide culling activities, including trapping, controlled shooting, drive shooting, and aerial gunning that incorporated a centralized bait station, had no effect on size of areas used by feral swine, but movement rates at bait stations were greater compared to control sites (Campbell et al 2012).…”

“…There have been no research efforts devoted to understanding how multiple types of removal activities might affect feral swine behavior in North America (except, see Campbell et al 2012). Our study goals were to determine if repeated simulated removal activities altered the size or location of space-use areas and assess differences in feral swine movements before, during, and after simulated removal activities.…”

Evaluation of movement behaviors to inform toxic baiting strategies for invasive wild pigs (Sus scrofa)

“…Use of the landscape by wild pigs is primarily driven by the location and availability of food and water . However, previous research has shown that wild pigs will adjust their space‐use to utilize transitory anthropogenic food sources, such as bait or crops .…”

“…8 Use of the landscape by wild pigs is primarily driven by the location and availability of food and water. [9][10][11][12] However, previous research has shown that wild pigs will adjust their space-use to utilize transitory anthropogenic food sources, such as bait or crops. [10][11][12][13] Some wild pigs shift their home ranges to include these types of resources or constrict their movements around such resources demonstrating the importance of thoughtful spatial strategies when deploying bait stations to maximize bait delivery.…”

Camel culling and carbon emissions in rangelands in central Australia

“…Despite the devastating history of many lethal control programmes, removal has a legitimate role in wildlife management in many countries and does contribute to coexistence between people and wildlife (Treves and NaughtonTreves 2005). As lethal wildlife management is an important approach in environmental management, and has been practised on various wildlife species in many countries, such as feral camels in Australia (Edwards et al 2008), elephants in Africa ( van Aarde, Whyte and Pimm 1999;Koenig 2007), swine in the US (Campbell et al 2012), it is critical to understand the environmental consequences of such a management approach. Carbon emissions are one part of such consequences that requires concern.…”