Nest-boxes for raptors as a biological control system of vole pests: High local success with moderate negative consequences for non-target species

• Published in: Biological Control
• Main Authors: Paz, Alfonso, Bintanel, Héctor, Viñuela, Javier, Villanúa, Diego
• Other Authors: Fundación BBVA, Ministerio de Economía y Competitividad (España)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2020
• Subjects: Biological pest control; Rodent outbreak; Predator-prey relationship; Ecologically based management rodent pest; EBMRP; Microtus; Common vole; Microtus arvalis
• Online Access: http://hdl.handle.net/10261/221553; https://doi.org/10.1016/j.biocontrol.2020.104267; https://doi.org/10.13039/501100003329; https://doi.org/10.13039/100007406

Biological control of rodents in agricultural areas, increasing avian predator abundance by nest-box provisioning, has been proposed during the last decades in several regions around the world as an alternative to the widespread use of anticoagulant rodenticides (AR) to protect crops. However these experiences have often lacked a “Before-After-Control-Impact” (BACI) experimental design providing evidence strong enough about their efficacy reducing vole abundance or crop damages. Furthermore, little is known about possible indirect effects on non-target species. Here we test the effectiveness of providing nest-boxes to common kestrels (Falco tinnunculus) and barn owls (Tyto alba) in reducing the abundance of two different vole species using indirect index methods to estimate rodent abundance in late spring (May). We monitored the abundance of both vole species in a treatment (with nest boxes) and control (without nest boxes) areas during three years in alfalfa fields, using a BACI design. We studied also the efficiency of this control method in three different crops (alfalfa, cereal and fruit-trees) during the last year of the experiment. We compare the results obtained in this study area in NE Spain with those obtained simultaneously in other three experimental areas in NW Spain. Finally we explored potential negative effects of this method on the abundance of several passerine birds present in our research area. Our results showed a clear-cut reduction in the abundance of the two vole species, the common vole (Microtus arvalis) and the mediterranean-pine vole (Microtus duodecimcostatus) in the experimental area after applying the treatment (nest box installation) in alfalfa crops. We also found a significant decrease in the presence of both species of voles on fruit-tree plantations and alfalfa crops but we did not find significant effects in the cereal fields, where voles were in general very scarce. These results suggest higher efficacy of biological control in this study area than in some areas of NW Spain, ...