Why do robins lay blue eggs? It seems kinda counterintuitive to have brightly visible eggs that are easily seen by predators.
it's so they can recognize their own eggs!
a predator really won't be able to see the eggs in the first place unless it's already found the nest, meaning it's going to find those eggs anyway at that point, so robins made their eggs a brilliant sky blue as an adaptation against brood parasitism.
brood parasitism can be a major concern for songbirds, because it means that parent birds will raise an unrelated species instead of their own offspring, and this may be the only breeding season they get if they're unlucky.
(note that cowbirds and cuckoos are NOT EVIL, this is just nature!)
BUT BACK TO ROBINS:
one of these is a cowbird egg, can you tell which?
SO CAN THE ROBINS. that little sucker is getting yeetus the fetus'd as soon as mom or dad returns from foraging and finds a weird little not-blue egg in the nest.
which is just another reason why robins are so successful! we're knee deep in these suckers every spring and summer because they are in fact, VERY good at being birds.
bop bop.
