This is an excellent footage capturing the behavior of a ground nesting nightjar. These birds are night-flying aerial insectivores active during dusk and dawn. It is almost impossible to see them during the day because of their camouflage. Nightjars are also known as goatsuckers which has no biological basis. If an intruder comes dangerously close to the nest, adults perform a well-known “broken wing” display. It is an excellent visual distraction. The bird will easily disappear soon after the intruder is at a safe distance. In this footage you can see an adult bird returning to its nest after a successful evasive flight.
Alfred Russel Wallace, another influential biologist contemporary to Charles Darwin who also independently came up with the idea of natural selection argued that dull coloration could arise because females face different risks than males, being burdened with motherhood. In his 1867 essay titled “Theory of Birds’ Nest” he elaborated why being less noticeable can be an adaptive trait.