Effectiveness of vole control by owls in apple orchards

Abstract

1. Biological pest control is gaining greater acceptance as an important part of integrated pest management for sustainable agriculture. However, knowledge regarding biological control of rodent pests is limited, and its effectiveness in temperate areas has not been quantified. In traditional Japanese apple orchards, the Ural owl Strix uralensis breeds in tree hollows and preys on the Japanese field vole Microtus montebelli, a native pest species that can harm fruit production. In this study, we hypothesised that the Ural owl, a generalist predator, can act as a biological control agent by reducing vole densities in temperate orchards.2. To quantify the pest control effects of breeding Ural owls, we first analysed the diet of individual owls nesting in apple tree hollows. Second, we installed nest boxes in orchards to attract breeding owl pairs and collected data on vole population changes around owl nests to compare with control areas. The population changes were analysed using a generalised linear mixed model to assess the effect of breeding owls within their breeding territory. The model considered seasonal fluctuations in vole population size as well as surrounding land-use. We also examined vole populations around the owl nests in April, and the distance between nests and forested areas, to determine if these variables influenced nest site selection.3. Voles were the primary prey of Ural owls breeding in orchards and the owls reduced vole populations within their estimated breeding territories by 63% (±SE: 53%-70%) compared with the predicted density without owls. Owls preferred to nest in orchards with higher vole population densities in April. Our findings also indicate that higher occupancy rates are possible by distributing nest boxes based on Ural owl breeding territory size (306 m radius circle in our study). Synthesis and applications.As breeding Ural owls provide significant pest control effects within their breeding territories, the reintroduction of breeding Ural owl pairs within orchards would contribute to rodent pest control. Promoting the reproduction of native raptors in agricultural areas can be an option for developing integrated pest management while simultaneously maintaining regional biodiversity. K E Y W O R D Sbiological pest control, generalist predator, Japanese field vole, microtine population, orchards, predator-prey, rodent pest, Ural owl How to cite this article: Murano C, Kasahara S, Kudo S, et al. Effectiveness of vole control by owls in apple orchards. J Appl

Phase tipping: how cyclic ecosystems respond to contemporary climate

“…We believe that this approach will enable scientists to uncover P-tipping in many different cyclic systems from applications ranging from natural science and engineering to economics. For example, the predator-prey paradigm is found across biological applications modelling, including epidemiology [80], pest control [81], fisheries [82], cancer [83,84] and agriculture [85,86]. The fundamental relationship described in predator-prey models also appears in many areas outside of the biological sciences, with recent examples including atmospheric sciences [87], economic development [64,65], trade and financial crises [88][89][90] and land management [91].…”

Phase tipping: How cyclic ecosystems respond to contemporary climate

“…We believe that this approach will enable scientists to uncover P-tipping in many different cyclic systems from applications, ranging from natural science and engineering to economics. For example, the predator-prey paradigm is found across biological applications modelling, including epidemiology [76], pest control [77], fisheries [78], cancer [79,80], and agriculture [81,82]. The fundamental relationship described in predator-prey models also appears in many areas outside of the biological sciences, with recent examples including atmospheric sciences [83], economic development [64,65], trade and financial crises [84,85,86], and land management [87].…”

Mow the Grass at the Mouse’s Peril: Diversity of Small Mammals in Commercial Fruit Farms

“…Thus, even while recognizing negative small mammal impacts such as crop damage and monetary losses [3,7], the current position is to maintain their communities, even in agricultural ecosystems, as providers of ecosystem services [2]. Therefore, chemical-based pest management methods are being changed to those based on small mammal ecology [55] or biological control [29].…”

“…In general terms, small mammal diversity in agro-landscapes depends on several factors: (a) disturbance of the habitat [23], with medium levels of disturbance possibly supporting higher small mammal diversity [24]; (b) application of rodenticides and mechanical measures such as mowing, soil scarification, and traps, though these had no permanent effect on voles [15,25,26,27]; (c) nonlethal measures that affect the behavior and reproductive success of animals [28], such as biological pest control or the provision of owl boxes [29]; (d) time required for communities to restore from surviving individuals or migration from neighboring habitats [30,31,32]; (e) crop type [11]; and (f) biology and ecology of small mammal species [30].…”