Blackbird movements and habitat selection inform restoration of functional connectivity across cities

Although ecological restoration strategies are increasingly promoted to enhance biodiversity, ecosystem services and climate resilience in cities, little is known about their impact on functional connectivity. We integrated empirical movement data with spatially explicit connectivity modelling to assess how alternative urban restoration strategies may affect breeding habitat availability and functional connectivity for the common blackbird ( Turdus merula ) in Gijón (NW Spain). Telemetry data from 13 adults were used to assess home range size, movement distances and habitat selection within the urban matrix. This dataset allowed to parameterise resistance surfaces and identify potential breeding habitat patches, which served as nodes in a circuit-theory-based connectivity framework. To evaluate how different urban restoration strategies may influence habitat availability and connectivity, we compared three scenarios representing increasing levels of restoration intensity. Under baseline conditions, suitable breeding habitat was highly fragmented. Although nearly 10% of the study area was suitable, only one third was functionally connected. The “Connectors Restoration” scenario, adding small-scale linear connectors along streets, was predicted to substantially improve connectivity among existing patches despite it did not increase habitat availability. The “Targeted Restoration” scenario, promoting strategically selected public green areas, was associated with the highest efficiency, achieving large gains in habitat availability and connectivity with relatively limited restoration effort. The “Full Restoration” of all public green infrastructure yielded the largest absolute gains, but showed lower efficiency, indicating diminishing marginal returns at broader spatial scales. Overall, our results suggest that connectivity-informed planning may enhance landscape functioning in dense urban environments and highlight the importance of targeted restoration actions to maximise ecological outcomes under limited resources.