Defining optimal small woody features and water densities to maximize European turtle-dove (Streptopelia turtur) occurrence in French agricultural landscapes

Abstract

The European turtle-dove is globally threatened, suffering a widespread and sustained decline in numbers across its breeding range, partly driven by habitat loss. Although the effects of certain habitat features are recognized, questions remain as to which landscape elements should be given priority and in what proportions. We assess how different habitat elements influence the occurrence density of turtle-dove at two management scales (25 and 100 ha), using fine-scale GPS tracking data from 38 turtle doves in France during the breeding season. We found some non-linear responses, with a steeper increase in occurrence density up to at least 25 % small woody features (SWF) density or 10 % water density at a 100 ha scale, refining the proportion to nearly 50 % for SWF at a 25 ha scale. Additionally, at a 25 ha scale, broadleaved forest displayed a bell-shaped trend, indicating a positive effect up to 22 %, whereas vineyards showed a sharp initial decline at a 100 ha scale. Grassland was positively associated with occurrence at the 100 ha scale, whereas fodder, cereal, and broadleaved forest showed negative effects at the same scale, while fodder, build-up, and maize had negative effects at the 25 ha scale. Variable importance analysis revealed that water was the most influential factor at 100 ha, followed by SWF, while at 25 ha, SWF was dominant, followed by water, highlighting scale-dependent habitat preferences. Our study provides insights into the optimal densities of SWF and water resource required for effective conservation, offering valuable guidance for the management and restoration of turtle-dove breeding habitats in agricultural landscapes.