Animals are present on Itarsi - Bhopal line (above Narmada river).......even Tigers from Satpura tiger reserve have been run over by trains in Itarsi - Bhopal section ..........on Itarsi - Nagpur line there are no animals.......
I think the reason is that the route was constructed as single line initially during British time ...during doubling they selected alignment with less curves for 2nd line.....this may be the reason