Swifts challenge our understanding

Sometimes a story is worth reporting just because its findings open your mind and challenge you to reconsider what you though you knew. This is one such story and it is about some ordinary birds that live an amazing life.

Swifts are a species of bird that live on all the continents and also on some islands. They are incredibly successful and their Latin name (Apus) is derived from the Greek meaning “without foot”. No doubt the ancient Greeks dubbed them this way because the feet of the swift are small and hardly detectable when they fly and, as a new study has shown, they spend a remarkable amount of time in the air.

This new study was carried out using a new type of micro datalogger that was able to record acceleration and so indicate a bird’s flight activity. The researchers also added light sensors to the dataloggers to assist with geolocation. The dataloggers were attached to 19 common swifts that were later recaptured.

Swifts spend 99 per cent of their time, during the 10 months that are not breeding season, in flight.

The data gathered showed that the swifts spend 99 per cent of their time, during the 10 months that are not breeding season, in flight. Some birds did settle down at some points in that 10 months but other birds never did; they flew continuously. The birds’ flight activity was lesser during the day than at night as during the day they spent their time soaring on warm air currents.

We knew that swifts spent a lot of time in the air but not that they could be in the air 100 per cent of the time (aside from breeding). It is not as if swift’s lead short, brutish lives either as they can live up to 20 years. The researchers estimate that in a lifetime this means a swift can cover an accumulated flight distance equivalent to seven round-trips to the moon.

These simple but astounding discoveries challenge us to consider the capacity of the swift’s physiology and, of course, to ponder when do they “sleep” and what is the nature of that sleep? The researchers theorise that swifts may sleep during slow descents during dawn and dusk.

It all really raises more questions than it answers; which is why it is such a delicious piece of research as it gives us a glimpse into life in the swift lane.

Source: Current Biology