On Thursday, the 18th of July, the North Cornwall Bird Ringing Group ventured up to a Forestry England site on Bodmin Moor with an exciting mission: to ring and GPS tag Nightjars.
Our project involves equipping these fascinating birds with a GPS tag that also includes a small radio tag. You might wonder why we need both. The GPS tag tracks the bird’s movements, but we can only access this data once we retrieve the tag. That’s where the radio tracking comes in! The tag is attached to the bird using a thread that dissolves in water, so after it rains, the tag will fall off and we will track the tag using the radio system in order to retrieve it!
Once we retrieve the tags, we'll gain a better understanding of the Nightjars' behavior and ecology in the area. By tracking these birds during the breeding season, we can identify nesting sites, territory sizes, and foraging habits. This information is crucial for informing habitat management and conservation strategies in the area.
Tracking will also help us locate roosting spots, which we can then protect. Additionally, mapping their habitat use across agricultural land, woodland, and heathland will aid in future restoration efforts. We will be able to reveal survival rates and identify threats such as predation and habitat loss.
This knowledge supports effective, area-specific conservation measures and enhances our understanding of the Nightjars' life cycle and their adaptation to environmental changes in the area.
The evening kicked off with a warm and dry sunset. Brian Cresswell, a Nightjar and tagging expert from Dorset Nightjar Study Group, joined us. Brian is also the managing director of, Lotek, which designs and produces wildlife tracking systems globally. They are constantly improving the tags to make them lighter, more efficient, and suitable for different species.
Brian provided the team with valuable training on radio tracking, tag fitting, and shared some of the behaviors he's discovered through tagging.
We then set up our nets, creating three dog-legs across the site and adding white hankies to some, as these can attract males who mistake them for displaying rivals. To our delight, a Nightjar flew into one of the nets we’d just finished setting up! It was carefully extracted and taken to the ringing station. After fitting a ring and recording the bird's bio-metrics, we photographed the spots on its wings and tail. This data, collected over the past 20 years, helps us understand any differences in spot size on males and their significance. We checked if the bird was an adult in good health, making it suitable for tagging. This male was not only an adult but also in excellent health, with a beak full of moths!
Brian then trained Pete on how to fit the tags, as this would be Pete’s responsibility moving forward. The process involves cleaning a small patch on the bird's tail feathers and attaching the tag with a dissolvable string and sticky pad. The tag weighs just 2 grams. To put it in perspective, a fully fed Nightjar can carry up to 10 grams of moths! After tagging, we released the bird back into the night. On our next net round, we caught a healthy adult female and repeated the process, fitting the second tag.
Feeling very pleased with our successful evening, we wrapped up around 11:30 PM. Our next task is to retrieve the tags after the next rainfall to collect the data. We’re excited to find out where these Nightjars have been and share the results with you!
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