Small mammal responses to moose supplementary winter feeding

Simen Pedersen,Lucrezia Gorini,Christina Skarpe,Harry P Andreassen,Karen M Mathisen,Eivin Røskaft

doi:10.1007/s10344-014-0816-1

Abstract

Supplementary feeding of wild large herbivores is a widespread practice in North America and Europe. The presence of feeding stations may have ecological consequences through changes to animal distributions, patterns of herbivory and a net nutrient input into the ecosystem. In Fennoscandia, supplementary feeding of moose in winter (Alces alces) is increasing. Although it has been shown to affect bird communities, its effects on small mammal communities were unknown. Here, we studied the effects of moose supplementary feeding stations on plants and on abundance, reproduction, and biomass of small mammals in years with low and high vole abundance. We sampled small mammals with snap traps and conducted surveys of the field layer vegetation, at varying distances from moose supplemental feeding stations. Due to the vegetation changes induced by feeding stations, abundance of common shrews (Sorex araneus) and Microtus voles were positively affected by long-term moose winter feeding, while bank voles (Myodes glareolus) were not affected. Moose feeding stations did not affect reproduction, individual body mass, or the total biomass of small mammals. Moose winter-feeding stations have impacts on nontarget species, providing islands of preferred grass and forb habitat for Microtus spp. and common shrews, allowing them to penetrate into a matrix of less preferred forest habitat.

Highlights

Supplementary feeding of large herbivores is a widespread practice in North America and Europe (Putman and Staines 2004)
When the model type and nesting structure was given, we compared models with different explanatory variables based on Likelihood ratios for linear mixed effects models (LME), F tests for generalized linear models (GLM), χ2 tests for generalized linear mixed effects models (GLMM) and t tests for analysis of variance (ANOVA) (Zuur et al 2009)
Vegetation composition varied between the three distance classes (Table 1), with field layer vegetation in general being more affected by distance to feeding stations than the tree layer

Summary

Introduction

Supplementary feeding of large herbivores is a widespread practice in North America and Europe (Putman and Staines 2004). Goals of feeding include divisionary feeding to reduce damage to cultivated or natural vegetation and to reduce vehicle collisions (Gundersen et al 2004; van Beest et al 2010a), and supplementary feeding to improve the quality of trophy animals or to sustain higher populations for hunting (Rodriguez-Hidalgo et al 2010; Putman and Staines 2004). The presence of feeding stations may have ecological consequences due to the net input of biomass into the ecosystem. Since most of the supplementary food is consumed, effects on the vegetation are mainly expected to be mediated through the enhanced nutrient input from faeces and urine of large herbivores using the feeding stations, as well as from intense herbivory of natural vegetation (Gundersen et al 2004; van Beest et al 2010a). Similar changes have been observed around artificial waterholes (Andrew 1988; Brits et al 2002), in the latter case no biomass is added to the ecosystem

Objectives

Methods

Results

Conclusion