Data from: Community-wide epizoochorous interactions revealed from roadkilled mammals

This dataset contains records of roadkilled mammals collected in To Japan. For each individual, species, sex, body weight, and the presence of externally attached seeds were recorded. The data were collected to investigate seasonal variation in epizoochorous seed dispersal by mammals. This dataset can be used to explore ecological interactions between roadkilled animals and plant seed dispersal, with implications for understanding dispersal dynamics in fragmented landscapes. A lack of information persists on external seed dispersal interactions, despite the rich diversity of potential dispersers. Roadkills offer a unique opportunity to obtain ecological data directly from carcasses. For 18 years, we collected road-killed mammals in Toyama (Japan) and screened them for seed attachment. We then illustrated species interactions, quantified the number of plant species and seeds individual roadkill carried, and evaluated seasonal variations in the probability of seed attachment. We identified nine mammal species dispersing seeds from 16 distinct plant taxa. Most importantly, medium-sized mammals (1.5–10.0 kg) accounted for approximately 88% of roadkill carrying seeds, with raccoon dogs (Nyctereutes procyonoides) dispersing the most seeds. Likely due to seed-set phenology, we showed a significant increase in seed prevalence for roadkills occurring in autumn. We advocate for future studies in epizoochory to focus on potential animal dispersers community wide.