Achilles heel of a powerful invader: restrictions on distribution and disappearance of feral pigs from a protected area in Northern Pantanal, Western Brazil

Abstract

This paper focuses on a rare case of natural disappearance of feral pigs (Sus scrofa) in an extensive area without using traditional methods of eradication programs. The study was conducted both in the Private Reserve of Natural Heritage (PRNH) Sesc Pantanal and in an adjacent traditional private cattle ranch. In 1998, feral pigs were abundant and widely distributed in the PRNH. However, the feral pigs gradually disappeared from the area and currently, the absence of pigs in the PRNH contrasts with the adjacent cattle ranch where the species is abundant. To understand the current distribution of the species in the region we partitioned the effects of variation of feral pigs’ presence considering the habitat structure (local), landscape composition and the occurrence of potential predators. Additionally, we modeled the distributions of the species in Northern Pantanal, projecting into the past using the classes of vegetation cover before the PRNH implementation (year 1988). Our results show areas with more suitability for feral pigs in regions where the landscape is dominated by pastures and permeated by patches of Seasonal Dry Forest. The species tends to avoid predominantly forested areas. Additionally, we recorded that the environmental suitability decreases exponentially as the distance from water bodies increases. The disappearance of feral pigs in the PRNH area seems to be associated with changes in the landscape and vegetation structure after the removal of the cattle. In the Brazilian Pantanal, the feral pigs’ occurrence seems strongly conditioned to environmental changes associated to livestock activity.

Modelling species distribution from camera trap by‐catch using a scale‐optimized occupancy approach

“…Roe deer are found to shift between sites with high and low elevation (Coulon et al., 2008; Mysterud, 1999) but tend to avoid rugged terrain (Lone et al., 2014). Global wild boar distribution is limited predominantly by temperature, both high and low (Cordeiro et al., 2018; Markov et al., 2019). In the Jura Mountains, we expect that wild boar occupancy is positively affected by forest availability but negatively affected by elevation and human presence, while roe deer occupancy is positively affected by forest availability but negatively affected by elevation, ruggedness and human presence ( Prediction 2 ).…”

“…Roe deer are found to shift between sites with high and low elevation (Coulon et al, 2008;Mysterud, 1999) but tend to avoid rugged terrain (Lone et al, 2014). Global wild boar distribution is limited predominantly by temperature, both high and low (Cordeiro et al, 2018;Markov et al, 2019). In the Jura Mountains, we expect that wild boar occupancy is positively affected Instead of relying on the scale determined for the lynx study, we pseudo-optimized the characteristic scale of each variable (McGarigal et al, 2016).…”

Effects of afforestation on water resource variations in the Inner Mongolian Plateau

“…Being part of the Mongolian Plateau located in Eurasia, Inner Mongolia, whose terrain is dominated by plateau and mountainous areas, is an important ecological barrier in North China (Ouyang et al, 2018). In recent years, drought and anthropogenic impacts in the region have intensified sand and dust storms (Cordeiro et al, 2018). As a result, these particulates have changed the composition of dust clouds, which have affected most of the world to the extent that floating dust from Inner Mongolia can reach the Pacific Coast of North America (Cheng et al, 2006).…”