LB 25-218 - Mammal movement in riparian corridors: Linking natural habitats within an anthropogenic matrix

Rapid industrialization has restricted wildlife movement by severing necessary landscape connections. The resulting discontinuity has limited resource exchanges and increased competition between and among species. Of the remaining natural habitat, climate change alters the landscape at rates faster than wildlife can adapt to. To alleviate stress from habitat fragmentation, one strategy is to protect wildlife movement corridors. We propose the use of riparian areas as continuous natural pathways for wildlife to avoid highly impermeable developed landscapes. Another strategy is to protect residential habitat that is resilient to stochastic disturbances. We propose that riparian areas are resilient as they are rich in resources, experience frequent disturbance, and often support higher ratios of biodiversity to land area compared to other habitat types. Here, we used camera traps to determine whether stream and riparian habitats or terrestrial matrix habitats had the highest mammal richness, and if this relationship changed along a developmental gradient and at varying stream widths. We installed 72 camera traps among two study areas in British Columbia starting in April 2022. Each study area had 12 camera trap sites, containing groups of 3 cameras installed to survey the habitat types of interest. We collected 347,341 images over the course of the data collection period and had a total sampling effort of 13,378 camera trap nights. We classified 39 unique taxonomic groups of mammals, of which we identified 24 to the species level. Preliminary results from generalized linear mixed-effects models showed that matrix and riparian habitats had significantly higher species richness than stream habitats, but that there was no significant difference in species richness between matrix and riparian habitat. We observed 29 taxa in riparian habitat, 29 taxa in matrix habitat, and 23 taxa in stream habitat. We also found that 6 taxa used matrix habitat exclusively, while riparian and stream habitats had 5 and 4 unique taxa, respectively. Our results suggest that riparian areas are supportive of a wide variety of mammals, but that they cannot be the only habitat types left intact if the management goal is to retain all major biotic functional groups, a key to achieving resilience. Access to matrix habitat and connectivity to streams may be critical for species who have an obligate relationship to these habitat types. Further analysis will indicate where riparian areas might be most important for wildlife movement along a developmental intensity gradient, and which stream widths might support the highest biodiversity.