Most nightjars rely on their large eyes to locate and capture moths and beetles at night.
In some species the eyes have been found to contain droplets of oil, which are thought to enhance visual acuity at low levels. But even with this adaptation, night-time conditions can prove challenging.
So nightjars are most active just after dusk and just before dawn, when there is sufficient light.
Foraging deep into the night only occurs when the sky is clear of cloud and the moon is bright.
In fact some species of nightjar align their breeding season to the lunar cycle, matching the period of chicks’ peak food demand with a full moon.
Many use artificial light too, feeding on moths and beetles attracted to streetlights.
Another adaptation is a wide gape – nightjars catch prey in their mouths and swallow it whole.
Their beaks are also fringed with strong bristles to increase their effective size.
Did you know?
The call of Africa’s fiery-necked nightjar is often rendered as ‘Good Lord deliver us’.
The European nightjar is a summer visitor to the UK, and overwinter south of the Central African Tropical Rainforest.