Surveying Nightjar with the BTO
Whilst in Norfolk at the end of June for my work experience placement at the BTO, I was offered the chance to join a group heading out into Thetford Forest one evening to find and survey the nightjar living in the area. I jumped at this opportunity, and it turned out to be a fantastic night.
Thetford Forest is the largest lowland forest plantation in Britain, and is full or patches of recently felled or new conifer plantations which provide great habitat for the Nightjar. This makes it possibly the best area in the county for surveying the nightjar.
Throughout the week there had been fears of evening rain that would force the survey to be cancelled and postponed to a different evening in the next week. But, luckily for me, the rain held (just about) on the Thursday that I was joining the group, so we headed off at around 8pm into the forest.
The BTO conduct these surveys of the nightjar in the area to monitor their populations and to help advise the landowners and Forestry Commission on what habitats or areas are used by the birds when they come to the UK to breed, and therefore which locations should be managed or left alone. The BTO also catch, ring and attach GPS tags to the nightjar here to help monitor survival rates and collect information on the movements of the birds. GPS tagging also helps the BTO to identify feeding areas during the breeding season. They also attempt to re-catch the Thetford birds to track migration. If you would like to learn more about bird ringing, see the BTO ringing page here. For more information on the Nightjar project, click here.
The night started with us driving along small dirt tracks leading into the forest until we came across open areas of bracken and heather, which would be the location of our first task - finding nightjar nests. I had only glimpsed nightjar before this point - in Turkey sat on the side of the road - so to see one properly and to see first hand how the birds nest and what the nests and eggs look like was a very exciting prospect.
As we searched the conifer compartments, we came across something very interesting before finding our first nightjar. A Tree Pipit suddenly sprung up from the undergrowth in front of us and began to stagger across the floor as if it was injured. It was in fact faking a broken wing, with the aim of distracting a predator away from the nest or young by making itself out as an easy meal. It was certainly very convincing - my dad and I were certain it was an injured bird until we got a little too close and it flew off as if nothing had happened. Amazing.
Soon we were back to nest-finding, and it wasn't long before we found our first nightjar nest. As the female flew up and into a nearby tree, we all stopped and soon found the nest. I say nest, but this wasn't your stereotypical bowl-shaped nest made of twigs. This was more of a little scrape in the ground. But this made it less obvious, and kept what was inside very well camouflaged. Sitting on the floor was a nightjar chick. The chick was very small and very difficult to spot with its mottled grey feathers. It was starting to get some of the more obvious features of a nightjar, notably the strange beak that can open ridiculously wide. This was an absolute treat to see for myself. But after taking a few photos, we left it be, being careful not to trample too much of the bracken around the nest to ensure it was still well hidden. We then promptly left the compartment to allow the mother to return and look after the chick.
From here we split up into two groups and headed off in separate directions to search the next set of compartments. We found one more nest once we had split up, with the other group finding two. This second nest was concealed amongst the bracken, and held two eggs this time. The eggs were fairly non-descript, but surprisingly well camouflaged, and it took us a while to find them amongst the vegetation.
Now that the light was fading, we finished searching for nests and headed for a larger, more open area to watch the nightjars as they began to emerge for a night's hunting. And sure enough, only a few minutes after arriving, a haunting sound drifted up from the bracken. The males had started churring! This was, surprisingly, the first time I had heard nightjar churring so it was fantastic. After about ten minutes, we had 4 or 5 different males calling simultaneously from different corners of the bracken field.
As the night went on, I managed to record a few minutes of the churring, which can be heard in the video below:
A short wait after the churring had begun, we got to see our first nightjar of the night. Males and females began to spring up from the undergrowth and fly low over the bracken. Despite the oncoming darkness, our binoculars still worked well, and we managed to watch the birds as they flew around the area for quite a while. The males were relatively easy to tell from the females by the distinctive white flashes on their wings and tail. The males also started wing-clapping, which I presume is a show of strength. I was amazed at how loud the wing-clapping was. I was expecting a muffled smack, but when the birds hit their wings together underneath their body it created quite a noticeable clap that echoed around the area of forest. Very cool!
The nightjar continued to fly around our heads for quite a while. I then learned that the birds would soon leave the area around their nests once it was dark enough, and fly off to nearby heathland to hunt, returning maybe one or two times during the night to tend to the nest and the chick. But whilst nightjars flying around our heads, we spotted another nocturnal bird - one that I wasn't expecting to see.
Two Woodcock flew over our heads, low enough to get a great view of them through our binoculars. Despite the rapidly fading light, we managed to watch these two birds flying around the area for quite a while before they disappeared into the black of the forest.
|Woodcock in flight|
credit Stefan Berndtsson, license, cropped
Having watched the nightjar flying around the area for a bit, it was now time to see if one could be caught to be ringed, processed and tagged. As well as providing great scientific data, this process would also allow me to see one of the most mysterious nocturnal birds in Britain up close.
So the nets were set up, and we waited to see if we'd catch one to process. Whilst waiting, we heard plenty more churring that continued well into the night, making the whole experience very atmospheric. We also, being stood still, had quite a few male nightjars flying very low over our heads, which was very exciting as they came out of nowhere and gave us some great views.
But unfortunately, as the night wore on, it wasn't looking very likely we would catch one, so we packed up and headed for home. But we certainly weren't disappointed. We had got some great views of some great birds - including an unexpected view of Woodcock. And finding a Nightjar nest, and seeing a young chick was something I certainly didn't expect to see.
I want to thank the BTO for giving me this opportunity whilst on my placement. And special thanks to Greg Conway for having me along for the evening, and for reviewing this post before it was published. It was fantastic to properly see Nightjar, and to get a great insight into some of the brilliant fieldwork carried out by the BTO.