Effects of changed grazing regimes and habitat fragmentation on Mediterranean grassland birds

Abstract

In Iberian cereal-steppes, decoupling of payments from current production levels through the Single Farm Payment raised concerns regarding the potential for land abandonment and replacement of sheep by cattle, with eventual negative consequences for declining grassland birds. This study addressed this issue by analysing the responses of five grassland bird species of conservation concern to spatial land use gradients, which are expected to reflect changes potentially associated with the CAP reform. Our results show that both habitat fragmentation and grazing regimes were major drivers of breeding bird densities, though responses to these factors were species-specific. Thekla larks were most abundant in landscapes with small grassland patches and high edge density, whereas calandra larks were abundant only in large expanses of continuous open farmland habitat. Little bustard and short-toed lark densities declined in highly fragmented landscapes, but they appeared to tolerate or even benefit from low to moderate levels of open habitat fragmentation. Corn buntings were little affected by landscape patterns. At the field scale, little bustard and corn bunting densities were highest in fields grazed by cattle, whereas short-toed larks were mostly associated with sheep pastures. Short-toed larks and Thekla larks were most abundant in old fallow fields where cattle was largely absent, whereas corn buntings showed the inverse pattern. These results confirm the view that the same agricultural policies may be favourable for some species of conservation concern but detrimental to others, and so they cannot be assumed to bring uniform conservation benefits.

Does afforestation increase bird nest predation risk in surrounding farmland?

“…Non-lethal effects may also be relevant (Cresswell, 2008), as perceived predation risk may induce individuals to avoid breeding or foraging near wooded edges and in small patches (Ribic et al, 2009 and references therein), thereby causing reductions in the amount of usable habitat that are much larger than the area effectively occupied by forest plantations ). However, although some species of conservation concern show avoidance of forest edges (Stroud et al, 1990;, others may show no avoidance or even preference for this habitat type (Avery, 1989;Reino et al, 2009Reino et al, , 2010. Also, while many studies have documented increased predation rates at habitat edges (review in Batáry and Báldi, 2004), such an effect was not found by studies focusing specifically on forest plantations .…”

“…The study focused on fallow fields, because they are particularly important for grassland birds (Delgado and Moreira, 2000;Reino et al, 2010), and to reduce variation among sites unrelated to forest and landscape features . Sampling sites were selected according to Reino et al (2009), involving the identification of all forest plantations from land cover maps (http:// www.igeo.pt/IGEO/portugues/produtos/inf cartografica.htm) and systematic field surveys.…”

“…Afforestation with umbrella pines (Pinus pinea) and holm and cork oaks (Quercus suber) has increased since the early 1990s due to EU subsidies, mainly in the periphery of the SPA. Details of the study area are reported elsewhere (Delgado and Moreira, 2000;Moreira et al, 2005;Reino et al, 2009Reino et al, , 2010.…”

Predicting the spring abundance distribution of red-legged partridge populations in agricultural regions using environmental models and an application for game management

“…Agricultural intensification and land abandonment represent an important threat for farmland wildlife in southern Europe (Bignal & McCracken 1996, Pain & Pienkowski 1997, Aebischer & Lucio 1997, Meriggi & Mazzoni della Stella 2004). According to Reino et al (2010) the same agricultural policies may be favourable for some species of conservation concern but detrimental to other farmland birds. Consequently, they cannot be assumed to bring uniform conservation and management benefits (Suárez-Seoane et al 2002, Báldi et al 2005.…”

Spatial analysis of lanner falcon habitat preferences: Implications for agro-ecosystems management at landscape scale and raptor conservation

“…AES were introduced into EU law in the 1980s, and although designed primarily as a production control measure, they rapidly became the most important support to biodiversity in agro-ecosystems across the whole Europe (Whittingham, 2007). Depending on the species and landscape studied, AES were successful for some species and neutral for others (Batáry et al, 2011;Broyer et al, 2014;Reino et al, 2010), or even had negative effects (6% of cases reviewed in Kleijn and Sutherland, 2003). Nonetheless, Kleijn and Sutherland (2003) found a positive response for biodiversity in the 54% of cases reviewed across Europe, as well as many recent studies on plant and animal diversity did (e.g.…”