Agri-environmental measures and the breeding ecology of a declining farmland bird

Abstract

Agricultural intensification is a key cause of the population declines shown by many farmland bird species across Europe. Changes in land management through agri-environment schemes (AES) are frequently cited as the best tool to reverse these trends, to date however they have received mixed support. This study tested whether AES options in England that provide winter seed food or insect-rich foraging during the breeding season, were associated with improved breeding performance in tree sparrow, Passer montanus, and/or the formation of larger breeding colonies. Breeding attempts (n=428) representing 210 pairs of tree sparrow comprising 22 colonies were compared in Wiltshire, England in 2013 and 2014. The area of margin AES, an insect-rich habitat, was positively correlated with fledgling success per breeding attempt and per breeding pair. Colony size increased with increasing wild bird seed mix AES area, a winter seed food resource, but this option negatively affected hatching success and the number of fledglings produced per breeding attempt. The observed association between colony size and this habitat was expected given that wild bird seed mixtures provide important seed food resources for granivorous birds during winter. The negative correlation with fledgling success, on the other hand, requires further investigation to determine whether this relationship relates to a lack of invertebrate and seed food during the breeding period. These results highlight the importance of providing a suite of AES habitats that are appropriately located to deliver both overwintering and breeding requirements of target, declining farmland birds.

Effects of higher‐tier agri‐environment scheme on the abundance of priority farmland birds

“…Despite increased counts of both species on HLS farms in 2011, abundance returned to 2008 levels by 2014 and no overall effect of AES status was detected. We note evidence from other studies that AES‐type habitat provision can enhance breeding success and breeding densities of both species (Aebischer & Ewald, ; McHugh et al ., ).…”

Population responses of farmland bird species to agri‐environment schemes and land management options in Northeastern Scotland

“…For example, reed bunting abundance was enhanced by the creation of water margins which provide tall dense vegetation next to watercourses, the species' preferred nesting habitat (Brickle & Peach, ). AES options can also benefit farmland biodiversity through invertebrate food resource provision (e.g., McHugh, Prior, Grice, Leather, & Holland, ; Vickery, Feber, & Fuller, ), and this probably explained the positive associations between creation and management of species‐rich grasslands and wetlands options with yellowhammer abundance. Further examples of the conservation benefits of targeting AES options to species' ecology include corn bunting population increases in the FBL scheme following delayed mowing of meadows (Perkins et al., ).…”

Finer‐scale habitat predicts nest survival in grassland birds more than management and landscape: A multi‐scale perspective

“…This can lead to fewer and shorter foraging bouts for parents (Chalfoun & Martin, 2007), which reduces predator cues to nests (Eggers, Griesser, & Ekman, 2008) and gives parents more time to engage in parental nest defence and attentiveness (Martin, 1987). Similar effects of increased arthropod food availability are suggested to improve breeding success of several European farmland birds (i.e., skylarks Alauda arvensis, corn buntings Miliaria calandra, tree sparrows Passer montanus) on set-aside and Agri-Environmental Scheme habitats, compared to traditional agricultural practices (Brickle, Harper, Aebischer, & Cockayne, 2000;McHugh, Prior, Grice, Leather, & Holland, 2017;Poulsen, Sotherton, & Aebischer, 1998…”