Supplementary feeding can attract red squirrels (Sciurus vulgaris) to optimal environments

Abstract

A number of conservation approaches are used to manage threatened species. However, some of these approaches require intensive planning and can often be restricted by funding. Supplementary feeding is a non-invasive and cost-effective approach to manage vulnerable populations, but we lack data on its usefulness. Here we investigated the effects of supplementary feeding on a population of red squirrels (Sciurus vulgaris), a UK priority species which faces competition from the non-native grey squirrel (Sciurus carolinensis). The study took place October-December 2015, lasting 8 weeks. Twenty feeders were installed 1 week prior to the beginning of the study in a protected woodland free from grey squirrels, either containing food (full feeders) or no food (empty feeders), and squirrel abundance before and after feeding was recorded at each feeder (for a total of 27 feeding and recording events). Six times more squirrels were seen at full feeders, and numbers increased by 7 fold after feeding. We also observed that the activity of red squirrels in the vicinity of full feeders increased during the course of the study. Eighty-five hair samples were collected during the study, all of which were found at full feeders. Results demonstrate red squirrels can differentiate between full and empty feeders, suggesting their awareness increases when supplementary food is present. Increased abundance of squirrels at full feeders after feeding times not only implies that squirrels are attracted to and can benefit by supplementation, it also shows that food supplementation can be used to regulate the movement of individuals across habitats. Understanding how red squirrel populations are affected by supplementary feeding will contribute towards existing conservation efforts to improve this species future survival.