Interesting pattern you've flagged there. I've been cross-referencing reports on the BFRO database and a few of the American sighting maps, and the railroad correlation does seem oddly consistent - particularly in the Midwest states.
My working theory, for what it's worth: old rail lines cut through terrain that was never properly developed afterwards. Overgrown embankments, culverts, abandoned depots - essentially undisturbed corridors running for miles. If something large and territorial exists, those would be ideal travel routes. Same reason we see big cat sightings along old drovers' roads here in Cheshire, funnily enough.
What I'd want to know is whether the sightings cluster around specific sections - curves, tunnels, bridges - or whether they're distributed evenly along the lines. That distinction matters. Predatory behaviour versus territorial marking would look very different spatially.
Has anyone actually plotted these properly on GIS mapping software? Feels like the sort of thing that deserves more rigorous treatment than a handful of anecdotes.
Also curious whether the railroad-adjacent sightings show any seasonal bias. Worth asking, surely?
