The blue eggs of an American robin in New Jersey, USA

© Mira/Alam

No egg dye required. Easter

The American robin doesn't go out of its way to hide its colourful eggs, nor does it need paint to celebrate Easter! Thanks to a process in the mother's blood, her eggs - which she can lay up to three times each year - are always this lovely shade of blue. There’s even a name for this natural hue, 'robin's egg blue'.

The American robin isn’t the only bird that produces coloured eggs. The emu (greenish-blue), great tinamou (turquoise), peregrine falcon (mottled brown), and red-winged blackbird (light blue with black spots) are just some of the others that can produce eggs worthy of an Easter egg hunt.