Since the publication of Charles Darwin’On the origin of speciesWe have discovered many things about the evolution of every being in Creation, but in reality we still know very little. Today we are dealing with an extraordinary peculiarity that is manifested in some birds’ eggs: bluish hues.
Blue jays, robins, bluebirds, starlings, house sparrows, singing thrushes, red-winged blackbirds and magpies are just a few examples of the small birds observed in Laying blue eggs. Unlike mammals, birds do not have a uterus, but a cloaca. It is functional for digestion and reproduction. Some species of birds, such as those listed above, produce a chemical pigment in the mantle: biliverdenAnd the responsible for blue shadows in the eggs of these flying animals.
A greater concentration of blue has also been documented in the first eggs, and then decreases with subsequent eggs. The latter can get a job Shades of green. But why does this phenomenon represent a benefit to the fetus?
The chicks are very sensitive to sunlight, in fact their parents build their nests in cool and shady places. However, blue would help More counteracting radioactive rays from the star. Obviously, there is a price to pay: the prey can easily identify the eggs, because they don’t blend into the eggs. Dedicated with the nest. Dark eggs remain Cool under the lightbecause too much radiation can be dangerous during incubation.
Staying on topic, have you ever wondered what is the difference between brown eggs and white eggs?