Swifts have been thriving for about 70 million years, when they would have been nesting in crevices in rocks and trees alongside the last of the Tyrannosaurs. But despite millions of years, something has now gone dramatically wrong, and UK numbers have plummeted in the last 25 years.
These extraordinary birds can remain in the air for three whole years because everything else apart from nesting is done on the wing. Only when they reach maturity and start to build will they touch anything solid.
No other bird can fly faster in level flight. They eat insects, drink raindrops or water from a lake, even mating and sleeping on the wing, up near Earth’s stratosphere. Their huge eyes are surrounded by bristles that act as sun visors and their feet are incredibly strong and so needle-sharp and tiny that they are unable to hop or walk, so they fly directly into the holes, cling to walls or slip into spaces where they can easily drop back out again.