Well they are more in the traditional mechanical engineering fields, namely petro-chemical, mining, transport, hvac etc. Or rather lets say heavy industrial.
Usually these industries are serviced by trade magazines, usually you can only get a hard copy, so very little online presence, and very little community participation (forums, user submitted content etc.)
I've never seen the need. Having a variety of tech sites usually gets the larger mechanical projects as everything is leading to Mechatronics anyway.
Exactly what kind of Mechanical engineering specialisation are they looking at?