Stochastic assessment of management strategies for a Mediterranean peri-urban wild boar population

Abstract

Wild boar (Sus scrofa) population spread into urban and periurban areas has exacerbated conflicts with humans. There is a need for planned wild boar management strategies, and Population viability analysis (PVA) combined with perturbation analyses allow the assessment of the management effort of control methods. Our study aims to develop stochastic predictive models of the increasing wild boar population of the 80 km2 peri-urban Mediterranean area of Collserola Natural Park (CNP), located near Barcelona, Spain, as well as assessing specific management measures (including reduced food availability, selective harvest, and reduction in fertility). Population parameters were estimated from previously published census and hunting data provided by the CNP and the local hunting administration. The results revealed that under the current conditions the CNP wild boar population will continue to increase. The most efficient strategy to reduce wild boar abundance was a combination of reducing supplementary anthropogenic food resources and selective removal of juvenile (<1 year) and yearling (1–2 years) wild boar. These strategies will probably be also the most efficient ones in other oversupplemented increasing wild boar populations in similar situations, although specific studies will be needed to fine-tune the best management option for each context. PVA allows the prediction of future population trends and the assessment of the efficacy and efficiency of potential management strategies before implementing management measures.

Too many wild boar? Modelling fertility control and culling to reduce wild boar numbers in isolated populations

“…Similar densities and levels of culling (21.1 per km 2 and 25% respectively) were also recorded for the Forest of Dean. The model's predictions on the effects of culling on wild boar numbers are consistent with previous studies suggesting that, in populations open to immigration, between 55 and 70% of a wild boar population should be removed each year to suppress population growth [8,17,35].…”

“…To capture the ecological processes within a closed population of wild boar we developed a stochastic stage-based Lefkovitch matrix model [49] explicitly dividing description into three distinct cohorts: piglets and sexually immature juveniles, all referred to as "juveniles" (<1 year old, as in [35]); sexually mature, adult, females (>1 year old); and, adult males (>1 year old).…”

Genetically similar hepatitis E virus strains infect both humans and wild boars in the Barcelona area, Spain, and Sweden

“…The ongoing expansion of wild boar populations leads to increasing contacts with humans, such as wild boars colonizing suburbs and urban areas, damaging crops and causing traffic accidents (Kotulski & König, ; Primi, Pelorosso, Ripa, & Amici, ). In the Collserola Natural Park (CNP), an 80 km 2 Natura 2000 site within the Barcelona Metropolitan Area (BMA), the wild boars invade suburban areas and parks, where their presence poses specific management problems and health issue challenges (González‐Crespo et al., ; Castillo‐Contreras et al., ; Cahill, Llimona, & Gracia, ; Cahill, Llimona, Cabaneros, & Calomardo, ). In Sweden, wild boars are entering into gardens, villages and farm lands to seek for food (Jansson, Månsson, & Magnusson, ).…”

Factors and costs associated with removal of a newly established population of invasive wild pigs in Northern U.S.

“…Increased use of bait sites during periods of climatic stress is supported by other studies where wild pigs and boars alter their behaviors during times of year when caloric or habitat requirements are not being met. Wild boar in Spain seek urban areas for anthropogenic food resources during warmer, drier months 51 – 53 . High daily temperatures have been reported to limit movements of wild pigs in North America 54 , 55 and Australia 56 , which could limit foraging efficiency 57 .…”