Nature Coloured Eggs

This is a read for nature lovers especially those of you who like birds like I do. Yesterday my attention was drawn to something in the lavender bushes in my garden that I had not seen before. It was a well-built open nest with a featherless baby bird and a couple of colourful blue-green speckled eggs. It was a lovely sight to behold and I moved away quickly and quietly in order to ensure that the mother bird came back.

The question then formed in my mind as to why some birds have such colourful eggs. All the years I had spent colouring Easter eggs had never generated such a strong, vibrant colour. The answer is that these eggs are produced by an order of birds called Passerines who mostly produce colourful eggs. The white or cream eggs are mostly produced by the non-Passerine birds, unless they are ground nesters which lay coloured eggs to blend with the ground cover.

The Passerines are the birds that perch on trees and caves and set forth the wonderful bird songs or ‘tweets’ that we hear often in our gardens, backyards and parks. They make up more than 50% of the birds species, have twelve tail feathers and are generally smaller birds with three toes pointing backward and one forward in order to keep them from falling off their perches. Some of these birds include the sparrows, jays, wrens, larks and blackbirds.

The Passerines produce colourful eggs and the reasons are intriguing. The blue green eggs are apparently caused by the bile-derived biliverdin and zinc chelate pigments. The red and brown eggs produced by other birds are due to the haemoglobin protoporphyrin pigments and this accounts for the spotting on the eggs, as well. There are hypotheses about why the passerines produce such coloured eggs and this includes for adaptive or post-mating purposes. There is new scientific evidence that suggested that the pigmentation reduces the brittleness of the egg shells especially as the female bird matures and has her calcium store reduced.

Armed with my new knowledge I made a discreet visit to the nest. As I approached it, I spied the little blackbird sitting in it. I smiled with delight and backed away. It would be all right now that the mother bird has returned to its nest. I will check again in a few weeks time and hope that the nest will be empty and that the new birds are learning to fly and sing somewhere in the garden.