I was on the minibus (a miniature bus in Hong Kong) today and a few House Swift came close enough to be identified.
What is your best wildlife tick, seen from public transport? It has to be genuine public transport, not a safari van. Ideally it would be on land - many ferries would pass by lots of interesting birds.
Part of the DART line in Ireland (urban rail) passes along sea cliffs, and I have seen Harbour Porpoises, Gannets and Fulmars from the train while on my way into the city. That was many years before iNaturalist though.