Table 1. Summary of the explanatory variables used for the HSMs.
The national models were performed at a 1–3 km resolution, while the road models were performed at a 100–500 m resolution.
| Explanatory variable | Resolution | Source |
|---|---|---|
| Arable (% cover) | 1–3 km | Land cover 2007 (LCM: Morton et al., 2011) |
| Broadleaved (% cover) | 1–3 km | Land cover 2007 (LCM: Morton et al., 2011) |
| Coniferous woodland (% cover) | 1–3 km | Land cover 2007 (LCM: Morton et al., 2011) |
| Urban (% cover) | 1–3 km | Land cover 2007 (LCM: Morton et al., 2011) |
| Improved grassland (% cover) | 1–3 km | Land cover 2007 (LCM: Morton et al., 2011) |
| Rough grassland (% cover) | 1–3 km | Land cover 2007 (LCM: Morton et al., 2011) |
| Freshwater (% cover) | 1–3 km | Land cover 2007 (LCM: Morton et al., 2011) |
| Greenspace (% cover) | 1–3 km | OS MasterMap Topography Layer (2019) |
| Hedgerow density | 1–3 km | Woody linear features (Scholefield et al., 2016) |
| Slope | 1–3 km | SRTM slope DEM (Pope, 2017) |
| All road traffic | 1–3 km | data.gov.uk (2019) |
| B road density | 1–3 km | OS Open Roads (2019) |
| Major road density | 1–3 km | OS Open Roads (2019) |
| Major road traffic | 1–3 km | data.gov.uk (2019) |
| Minor road density | 1–3 km | OS Open Roads (2019) |
| Minor road traffic | 1–3 km | data.gov.uk (2019) |
| Population density | 1–3 km | EEA (Gallego, 2010) |
| Summer precipitation | 1–3 km | Worldclim—global climate data (Fick & Hijmans, 2017) |
| Summer temperature | 1–3 km | Worldclim—global climate data (Fick & Hijmans, 2017) |
| Distance from arable (m) | 100–500 m | Land cover 2007 (LCM: Morton et al., 2011) |
| Distance from broadleaved woodland (m) | 100–500 m | Land cover 2007 (LCM: Morton et al., 2011) |
| Distance from Greenspace (m) | 100–500 m | Land cover 2007 (LCM: Morton et al., 2011) |
| Distance from buildings (m) | 100–500 m | Land cover 2007 (LCM: Morton et al., 2011) |
| Distance from improved grassland (m) | 100–500 m | Land cover 2007 (LCM: Morton et al., 2011) |
| Distance from urban area (m) | 100–500 m | Land cover 2007 (LCM: Morton et al., 2011) |
| Distance from suburban area (m) | 100–500 m | Land cover 2007 (LCM: Morton et al., 2011) |
| Distance from major road* | 100–500 m | OS Open Roads (2019) |
| Distance from B road* | 100–500 m | OS Open Roads (2019) |
| Distance from minor road* | 100–500 m | OS Open Roads (2019) |
| Slope | 100–500 m | SRTM slope DEM (Pope, 2017) |
| HSM (1–3 km) | 100–500 m | – |