ORIGINAL PAPER Landscape effects on large scale abundance patterns of turtle doves Streptopelia turtur in Portugal Susana Dias & Francisco Moreira & Pedro Beja & Mariana Carvalho & Luís Gordinho & Luís Reino & Vanessa Oliveira & Francisco Rego Received: 11 July 2012 / Revised: 28 January 2013 / Accepted: 31 January 2013 / Published online: 9 March 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract The European turtle dove is both a highly valued game species and a species of conservation concern, which is declining due probably to a combination of habitat deg- radation and unsustainable hunting. Although declines seem to be less severe in the Mediterranean region, it remains uncertain the extent to which ongoing land use changes will negatively affect this species. This study examined this issue, by estimating the effects of landscape composition on the broad scale abundance pattern of breeding turtle doves in continental Portugal. Turtle doves were surveyed in the breeding seasons of 2002 and 2003, from 3160 point counts spaced at about 1-km intervals along 158 transects of about 20 km, evenly covering the country. The frequency of occurrence of turtle doves at each transect was used as a proxy of species abundance, and related using GAM mod- elling to 21 variables describing land cover and woody linear features (e.g., hedgerows and riparian galleries). Turtle doves were most abundant in north- and central- eastern Portugal, with high abundances also recorded in the regions around Lisbon and along the Guadiana valley. Abundances were positively related to forest cover, particu- larly by broadleaved forests and by pine stands without woody understory, to cover by permanent crops, and to the density of woody linear habitats. Results suggest that con- servation of Mediterranean turtle doves requires policies and management strategies reversing the pervasive trends of forest management neglect and agricultural abandonment, while preserving hedgerows and riparian galleries in more intensive agricultural landscapes. Keywords Conservation . Forest management . Habitat selection . GAM . Mediterranean landscapes Introduction Some bird species are both legally hunted and have unfav- ourable conservation status, making its management particu- larly challenging (Bro et al. 2001; Machado et al. 2008; Besnard et al. 2010). This is the case of the European turtle dove (Streptopelia turtur), a sub-Saharan migrant bird that has markedly declined throughout much of its European breeding range during the past decades (PECBMS 2009), and which has thus been considered a Species of European Conservation Concern (SPEC) (Jarry 1994). Reasons for the decline are still not completely understood, but they may include the degra- dation of breeding and wintering habitats, along with unsus- tainable hunting pressure (Browne and Aebischer 2005; Lutz and Jensen 2007; Eraud et al. 2009). Thus, understanding the factors driving the species occurrence and abundance remains a prerequisite for proper population conservation and man- agement (Lutz and Jensen 2007). This is particularly impor- tant in Euro-Mediterranean countries, where the population is still large but may be at risk from rapid changes in land cover Communicated by C. Gortazar Electronic supplementary material The online version of this article (doi:10.1007/s10344-013-0702-2) contains supplementary material, which is available to authorized users. S. Dias (*) : F. Moreira : M. Carvalho : F. Rego Centro de Ecologia Aplicada Prof. Baeta Neves, Instituto Superior de Agronomia, Universidade Técnica de Lisboa, Tapada da Ajuda, 1349-017 Lisbon, Portugal e-mail: susanadias@isa.utl.pt P. Beja : L. Gordinho : L. Reino : V. Oliveira CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-601 Vairão, Portugal L. Gordinho ERENA SA, Ordenamento e Gestão de Recursos, Rua Robalo Gouveia 1-1A, 1900-392 Lisbon, Portugal Eur J Wildl Res (2013) 59:531–541 DOI 10.1007/s10344-013-0702-2