Nesting and Brood-rearing Opportunities for Farmland Birds in and Around Miscanthus and Short Rotation Coppice Biomass Crops

Abstract

Reaching the EU target for renewable energy is likely to encourage a rapid expansion of biomass crop production in the UK.  This expansion could pose a considerable threat to farmland birds, via the loss of suitable nesting habitat for ground-breeding birds or by decline in availability and accessibility of foraging resource for other farmland birds.  Alternatively, the low-input management of biomass crops may provide benefits over more intensively managed arable crops.  The potential impacts of biomass expansion on nesting and foraging opportunities were therefore investigated by examining the nesting success of lapwings (Vanellus vanellus) in Miscanthus, and faecal components of songbirds nesting in boundaries of Miscanthus and short rotation coppice (SRC) willow fields.

Despite similar nest densities and field occupancy across crop types, lapwing clutches experienced lower hatching success in Miscanthus fields than in arable crops.  This result was mainly influenced by increased losses in 2012; a particularly wet breeding season.  In years of already unfavourable breeding conditions, nests in Miscanthus may therefore be more vulnerable and suffer higher predation rates than those in arable crops.

More invertebrates were found in SRC crop than in Miscanthus, and this was reflected in the faeces of whitethroat (Sylvia communis) chicks nesting in the boundaries of SRC and Miscanthus fields.  Despite lower availability of Coleoptera in Miscanthus fields than SRC, this was not reflected in faeces of whitethroats or yellowhammers (Emberiza citronella), suggesting birds nesting in Miscanthus may supplement chick diet with food found elsewhere.

Converting land to biomass crop cultivation may pose some risk to farmland birds, but while nesting and foraging opportunities may be limited in Miscanthus crop, SRC provides a more abundant foraging resource.  The extent of any risk will depend on the crops being replaced, the position of biomass crops within the landscape and the extent of biomass crop uptake throughout the UK. It is vital that government energy targets are met in a sustainable manner, which could be achieved if the expansion of the industry is managed sensitively.