How does shell color work to protect the egg from sunlight?

Birds that live in cool climates lay darker eggs, as darker colors absorb more heat from the sunlight

Birds that live in hotter climates lay lighter eggs to prevent the egg from overheating.

The pigmentation acts to thermo-regulate the internal temperature of the egg, acting as a buffer between the embryo and the outside world. It does this by preventing overheating of the egg, through reflecting the sunlight off the pigmentation, rather than allowing it to be absorbed through the shell

they both go up but then go back down. they both end lower than they started. lastly, they both are competitive/the second on.

explanation: