Is it me, or is it global warming?????

I have seen these hover flies frequently in the garden and on here.
I dont ever remember them up here in the wilds of the north as a lad.
Mind you insect life never interested me then, Tennants lager and women were more appealing.
We very rarely got magpies,collared doves either but that wasn't the kind of birds the drew my attention.
Anyway enough of my sordid past, is it globalisation of nature???