Nest

There are some animals in the wild who are indeed affected by human scent in or near their nesting grounds to the point that they will abandon their own offspring, born or unborn, but birds are not among those who exhibit this behavior.

Birds have an extremely poor sense of smell, so you could slather an egg or chick in human scent and it wouldn’t make an ounce of difference. This myth no doubt began as a way to deter good Samaritans from interfering when they see what they perceive to be a crisis, when really it’s just nature at work, teaching the bird to fly. If you find an egg or a nestling on the ground, if they are not physically harmed and you can locate the nest, by all means, put them back in their rightful place. However, if you happen upon a fledgling, who will have significantly more feathers and defined features than a nestling, better to leave it where you find it. Fledglings of many bird species are known to spend time on the ground or in low branches after leaving the nest while they develop their flight skills.