Interesting pattern. I came across a few older rail corridor reports when I was cross-referencing some Mothman sighting data a while back and the geographic overlap was odd enough that I bookmarked it for later.
My question would be - is it the corridors themselves or what they connect? Old rail lines often cut through terrain that was otherwise left undisturbed for decades, dense woodland, wetlands, that sort of thing. So are we looking at habitat corridors that these things actually use to move around, or is it just that rail lines give witnesses a clear line of sight and a reason to be out there at odd hours?
Has anyone mapped this properly? Like actually plotted the reports against the specific rail lines rather than just noting the proximity. Would be curious whether certain stretches show clustering or if its spread fairly evenly.