Male Chaffinch

It's been a few years since I have managed a shot of a Chaffinch in the garden.
    There were a pair there.But to get them together.And in focus, was nigh on impossible.
   So being as the male is the more colourful of the two? You have to suffer male dominance I'm afraid!

   A little help please!   Has anyone any experience of the new Tamron or Sigma 150-600 lenses please? As I am looking to get one.

  E-mail me on redken60@gmail.com if you prefer?