This couple of serins (Serinus serinus) was photographed at one of Porto's biological vegetable gardens. The male (on the left) is more colorful than the female (on the right).
<a href="//commons.wikimedia.org/w/index.php?title=User:Jo%C3%A3o_Manuel_Lemos_Lima&amp;action=edit&amp;redlink=1" class="new" title="User:João Manuel Lemos Lima (page does not exist)">João Manuel Lemos Lima</a>
CC BY 4.0
<span class="int-own-work" lang="en">Own work</span>