Data files used to accompany code for Paper 2

(i) AbstractUrban development and road infrastructure are key contributors to landscape fragmentation, posing significant threats to biodiversity. Wildlife underpasses are a common mitigation strategy for target species, yet their broader ecological effectiveness remains unclear. This study investigated wildlife tunnels designed for badgers (Meles meles) and amphibians along a 1.4km stretch of new road infrastructure. Clay mats were monitored daily for 9 consecutive days during summer to assess species activity. The results showed frequent usage by the European badger (Meles meles) and the red fox (Vulpes vulpes), however there was not much evidence of any other species using the structures. No significant relationship was found between tunnel use and tunnel attributes or proximity to landscape features. While the underpasses appear effective for medium sized mammals, the limited evidence of use by other wildlife highlights further study would be beneficial to assess seasonal use and broader ecological factors. Future research should focus on evaluating the sufficiency of current mitigation measures with particular focus on predator-prey dynamics and climate change to assess long-term effectiveness for both target and non-target species.