Anticipating Knowledge to Inform Species Management: Predicting Spatially Explicit Habitat Suitability of a Colonial Vulture Spreading Its Range

Patricia Mateo-Tomás,Pedro P Olea,Brian Gratwicke

doi:10.1371/journal.pone.0012374

Abstract

BackgroundThe knowledge of both potential distribution and habitat suitability is fundamental in spreading species to inform in advance management and conservation planning. After a severe decline in the past decades, the griffon vulture (Gyps fulvus) is now spreading its breeding range towards the northwest in Spain and Europe. Because of its key ecological function, anticipated spatial knowledge is required to inform appropriately both vulture and ecosystem management.Methodology/FindingsHere we used maximum entropy (Maxent) models to determine the habitat suitability of potential and current breeding distribution of the griffon vulture using presence-only data (N = 124 colonies) in north-western Spain. The most relevant ecological factors shaping this habitat suitability were also identified. The resulting model had a high predictive performance and was able to predict species' historical distribution. 7.5% (∼1,850 km2) of the study area resulted to be suitable breeding habitat, most of which (∼70%) is already occupied by the species. Cliff availability and livestock density, especially of sheep and goats, around 10 km of the colonies were the fundamental factors determining breeding habitat suitability for this species.Conclusions/SignificanceGriffon vultures could still spread 50–60 km towards the west, increasing their breeding range in 1,782 km2. According to our results, 7.22% of the area suitable for griffon vulture will be affected by wind farms, so our results could help to better plan wind farm locations. The approach here developed could be useful to inform management of reintroductions and recovery programmes currently being implemented for both the griffon vulture and other threatened vulture species.

Highlights

In the management and conservation of species it is fundamental to determine their current and potential distribution, as well as both the amount and arrangement of suitable habitats in a landscape [1,2]
Environmental factors According to maximum entropy (Maxent) jackknife analysis, the most important environmental variables in determining habitat suitability for griffon vulture were slope (51.24% of contribution) and sheep and goat LU density within 10 km (21.45% of contribution; Fig. 2 and 3)
The results clearly show that the griffon vulture could expand its breeding range west of the Cantabrian Mountains, increasing the total species range to around 1,782 km2 (Fig. 1 and 4) According to our model, this expansion could mainly occur through the center-southern part of the area, where habitat suitability is higher (Fig. 4)

Summary

Introduction

In the management and conservation of species it is fundamental to determine their current and potential distribution, as well as both the amount and arrangement of suitable habitats in a landscape [1,2]. Presence/absence models are frequently used to predict species’ distribution, but there is a common problem related to the uncertainty in determining absences [6], especially where the species does not occupy all available suitable habitats [7]. This is frequently the case in invasive [1] or native species whose distribution ranges have been either reduced or are still spreading. The anticipated spatial knowledge of these possible outcomes can be a very useful piece of information in order to advance the planning needed in management and conservation. Because of its key ecological function, anticipated spatial knowledge is required to inform appropriately both vulture and ecosystem management

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