Early season pollinators

While watching the honey bees foraging on the snowdrops and looking out for my first bumblebee the other day I noticed several hoverflies on the flowers as well.  With the help of the kind folks at the UK Hoverflies Facebook page they have been identified.  This is Eristalis tenax ♀, a female drone fly.  It is so called because it resembles a drone, a male honey bee.  This might be Batesian mimicry but it seems odd that a female fly would disguise itself as a male honey bee (which doesn't have a sting).  Perhaps it is just coincidence that it looks like a drone.

This one is a female Episyrphus balteatus, the marmalade hoverfly, presumably named for its colour.

The third one caused some difficulty but was identified as Syrphus torvus, also known as the hairy-eyed syrphus.

I hope I don't get too interested in hoverflies as there are nearly 300 UK species, although it will be good to see which ones turn up in the garden.