Our senior ecologist Aaron Grainger is taking part in an exciting research project to find out more about the private life of the mysterious nightjar, also known as The Goatsucker.
He reports,” A team from the London office is currently involved with some cutting edge work in tracking the movements of European nightjar in Nottinghamshire. Nightjars are nocturnal birds that migrate to the UK and other parts of Europe from sub-Saharan Africa each spring. They possess a cryptic plumage which makes them well camouflaged against a background of bark or leaves. During the day, nightjars will usually sit motionless on the ground or lengthways on an open branch to minimise the chances of being noticed by predators. During the breeding season, the males emit a characteristic ‘churring’ call which can be delivered continuously for up to 10 minutes from a perch. They feed on a wide variety of flying insects often catching moths, beetles and other invertebrates on the wing.
Interestingly, they have evolved bristles around their mouth that are thought to help with detecting the prey and funnelling it into their wide gapes. Even more curiously, nightjars have evolved a serrated claw which they use as a comb to removed unwanted insect parts such as moth scales from the bristles!
The nocturnal and secretive nature of nightjars can make it difficult to for us to gain useful information on their behaviour and movements using conventional survey methods. Our surveyors have been working with a local group of experienced bird ringers who have also been assisting with the British Trust for Ornithology’s high profile cuckoo project. The ringers possess a special licence to allow them to trap the birds in nets placed near their nest site. This does not harm the birds in any way and often when a bird has been caught once, they can be difficult to catch a second time as they are aware of what we humans are up to!
Once the birds are caught, biometric measurements are taken and a small radio-tag and GPS receiver attached to the bird. This new technology takes multiple locations of the bird over the course of a single night. This allows us to gain an insight into the area each individual is using for foraging. New tags are currently in development that will have a long-life battery capable of lasting the lifetime of the bird. Once available, it is hoped that they can be used on future surveys to ensure The Ecology Consultancy is using the newest, most effective technology available to maximise the amount of data collected when tagging rare birds such as nightjar”.
(Picture credits BTO Images: British Trust for Ornithology)