Bird of the week - Coal tit

The coal tit, Periparus ater, or Periparus ater britannicus.  Coal tits appear to be monogamous and usually stay paired for life.  However, all is not as it seems.  Older males are particularly prone to cheat on their partners and father chicks by other females.  Maybe the females prefer more mature males (sensible!) as they may have better genes for longer survival.  See here.