The Importance of Linear Landscape Elements for Bats in a Farmland Area: The Influence of Height on Activity

In the past 50 years, widespread removal of hedges and hedgerows in many European regions, with a consequent reduction in biodiversity, has occurred as a result of farming intensification. Acknowledging the ecological importance of linear farmland landscape elements, many agro-environmental schemes provide financial support for the management, conservation and reconstruction of hedges and hedgerows. The efficacy of such initiatives, also aimed at bat conservation, could be enhanced by including the role of hedges and hedgerows correlated to the variability of their physical structure and to the surrounding landscape context. Linear landscape elements are in fact of great importance to bats, whose flight activity tends to increase in proximity to hedges and hedgerows, used both during foraging and as commuting routes. Nevertheless, information concerning the correlation between various physical structures of hedges and flight and foraging techniques in bats is still lacking. The present study analyses the activity of bats along two different hedge types, with and without trees, and in open spaces, in an area of the Padana plane (North-western Italy) as a function of different flight behaviours.

Activity in bats appears higher along hedges than in open spaces but no significant differences are noted between the various hedge types under investigation. Foraging behaviour is primarily detected along hedges with trees but is lower along hedges without trees and in open spaces. This is particularly evident in bat species that have adapted to foraging in closed spaces surrounded by foliage (Myotis and Plecotus genera) or at the periphery of these environments (Pipistrellus genus), whereas it not seen species that forage in open spaces (Nyctalus genus). Hedge reconstruction aimed at bat conservation ought to, therefore, favour tall hedges with trees as opposed to low hedges without trees.