GIS-models work well, but are not enough: Habitat preferences of Lanius collurio at multiple levels and conservation implications

• Published in: Biological conservation Vol. 142; no. 10; pp. 2033 - 2042
• Main Authors: Brambilla, Mattia, Casale, Fabio, Bergero, Valentina, Matteo Crovetto, G., Falco, Riccardo, Negri, Irene, Siccardi, Paolo, Bogliani, Giuseppe
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2009; Kidlington, Oxford: Elsevier Science Ltd; Elsevier
• Subjects: Animal, plant and microbial ecology; Applied ecology; biodiversity; Biological and medical sciences; breeding season; Conservation, protection and management of environment and wildlife; environmental models; Fundamental and applied biological sciences. Psychology; General aspects; geographic information systems; grasslands; Habitat mosaic; habitat preferences; Lanius; Lanius collurio; Model validation; Multiscale; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; prediction; Predictive model; Shrike; shrubs; spatial data; wild birds; wildlife habitats; wildlife management; Italy; Model validation; Multiscale; Shrike; Predictive model; Habitat mosaic; Conservation; Habitat selection; Forecast model; Vertebrata; Geographic information system; Habitat; Aves; Environmental protection
• ISSN: 0006-3207; 1873-2917
• DOI: 10.1016/j.biocon.2009.03.033

Species conservation largely depends on knowledge of habitat needs of target species. GIS-models are increasingly used to assess habitat preferences and distribution of target species, but their accuracy is constrained by availability of digital data layers. We developed a two-steps approach aiming at showing pros and cons of landscape (GIS)- and site-level habitat models, identifying key habitat factors for conservation of a threatened bird species, the red-backed shrike Lanius collurio. A spatially explicit GIS-model was generated using landscape variables, and a second model at site level was developed using fine-scale variables measured on the ground. The GIS-based model was then extrapolated to the entire region to obtain a map of distribution of suitable habitats. Positive associations between shrike occurrence and both hedgerow length and partial shrub cover were detected at both scales. Shrikes were also positively associated with grassland cover at landscape level and with partial cover of untilled herbaceous vegetation at the finer scale, and negatively affected by lucerne cover. The GIS-model led to an affordable map of predicted habitat suitability which should help conservationists to focus on different local priorities, but was unable to identify effects of untilled and lucerne cover. Site-level model gave fine details for habitat management, but its application elsewhere requires ground-measurements of factors. Combining the multiscale models could indicate more urgent actions at large scales (e.g. maintaining suitable habitats, or improving connectivity among isolated patches) and draw a detailed figure of the most suitable habitat for the species. Shrike occurrence was associated with a higher number of shrub and tree species: the indicator value of the species should ensure general benefits for biodiversity from dedicated management.