A plastic device fixed around trees can deter snakes from predating bird nest boxes

J C Senar,H Navalpotro,D Mazzoni

doi:10.32800/10.32800/abc.2021.44.0103

Abstract

Several devices have been designed to prevent predation in nest boxes by mammals and birds. Although snakes are one of the most common predators in cavity–nesters, they have always been difficult to deter. Here we tested a method originally designed to avoid predation by tree–climbing mammals. To prevent snakes from climbing trees and predating on nest boxes, we wrapped a transparent acetate sheet of 80 cm high around tree trunks below a sample of 40 nest boxes used by tits. The acetate sheets were secured with duct tape. The remaining nest boxes (N = 74) in the study area were left as controls. The predation rate in the experimental nest boxes was 20 % and 2 % in control boxes. This method can be useful to increase bird breeding success, improving both the effectiveness of resources to obtain scientific data and the breeding success of endangered species.

Highlights

Cavity–nesting passerines are commonly used as research subjects in many ecological studies because they can be monitored using nest boxes
The results of this study indicate that wrapping the tree trunk with acetate sheeting decreased snake predation by preventing snakes from climbing up to nest boxes
The case in which we failed to deter snake predation was because the tree with the nest box was very close to another tree, so that the snake could have climbed this adjacent tree and jumped to the nest box on the nearby tree

Summary

Introduction

Cavity–nesting passerines are commonly used as research subjects in many ecological studies because they can be monitored using nest boxes. Several devices have been designed to deter predation in nest boxes by mammals and birds (Yamaguchi et al, 2005; Bailey and Bonter, 2017; Stojanovic et al, 2019). For nest boxes hanging from a branch, a cone–shaped piece of plastic put on the box can sometimes be effective (Bailey and Bonter, 2017). When the nest boxes are placed on a metal pole, a stovepipe baffle or cone baffle placed on the metal structure has shown to prevent climbing snakes from reaching the box (Bailey and Bonter, 2017). When nest boxes are located on the tree trunk and near the ground, no simple device seems available

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Conclusion