Assessing methods to live‐capture wild boars (Sus scrofa) in urban and peri‐urban environments

Abstract

BackgroundWild boar (Sus scrofa) populations are increasing worldwide and invading urban areas. Live-capture can improve the management of this challenge, maximising efficiency, allowing scientific studies and potentially improving animal welfare. This study assesses teleanaesthesia, drop-net, corral trap and cage trap to live-capture wild boar in urban and peri-urban areas, evaluating efficiency and animal stress through haematology and serum biochemistry.MethodsFrom 2012 to 2018, 655 wild boars were captured in 279 operations (drop-net=17, teleanaesthesia=186, cage trap=66 and corral trap=10) in the urban and peri-urban areas of Barcelona (Spain). Haematological and serum biochemical variables were determined in 145 wild boars (42 drop-netted, 41 teleanaesthetised, 38 cage-trapped and 24 corral-trapped).ResultsPerformance (wild boars captured per operation) was highest for drop-net, followed by corral and cage traps, and finally teleanaesthesia. The three physical capture methods were more stressful than teleanaesthesia, causing a more intense physiological reaction, muscular damage, renal function impairment and homeostasis adaption. Stress response was predominantly adrenergic for drop-net and cortisol-induced for cage and corral traps.ConclusionTeleanaesthesia is the choice in reactive urban situations thanks to its adaptability; drop-net effectively targets wild boars in peri-urban environments; cage and corral traps are useful as long-term methods in specific areas.

Research priorities to fill knowledge gaps in wild boar management measures that could improve the control of African swine fever in wild boar populations

“…The characteristics of WB trapping techniques (and their specificity) are variable (e.g. corral traps, cage traps, funnel traps; Hampton et al., 2019 ; Seward et al., 2004 ; Torres‐Blas et al., 2020 ) and present different advantages. Trap capture of WB should minimise negative effects on animal welfare, irrespective of whether the animals are trapped for hunting, research, or management purposes.…”

“…The assessment of the effectiveness of WB trapping as a sustainable culling method has yet to be done in the EU, particularly, in non‐urban or peri‐urban environments (Torres‐Blas et al., 2020 ). The key question is whether programmed and sustained WB trapping can control WB populations in the long term across Europe.…”

“…Behavioural (during and post‐release), pathological, haematological and biochemical assessments after capture events of WB (Fenati et al., 2008 , Barasona, 2015 , Fahlman et al., 2020 , Torres‐Blas et al., 2020 ) are required to evaluate capture‐induced stress in WB. Trap‐related pathological findings due to trauma and other indicators reveal that, under appropriate management conditions (e.g.…”

“…In areas where no other population management methods are available (e.g. hunting in urban areas or public parks), trapping is a feasible option for controlling WB population (Cahill et al., 2012 ; Torres‐Blas et al., 2020 ).…”

“…The drop‐net installation, monitoring and triggering should follow Torres‐Blas et al. ( 2020 ) and cage and corral trap should follow Barasona ( 2015 ). If remote triggering is not applied, trap deactivation must follow welfare regulations in place.…”