On Saturday night, we went straight from a swimming gala to Brimpt Woods, managed by Forestry England. Brimpts Wood is very close to Dartmeet, where the two branches of the River Dart meet. The West branch flows alongside the Woods, increasing the diversity of species in the area. I would be doing a nightjar survey for Forestry England, with the Dartmoor Youth Rangers. From 8:30PM to 11:00PM, we would be out in the dim dusk light, listening and watching for these phantoms of the night. It was overcast, slightly drizzly and teeming with midges, but I was ready for it! By the way, this is not part of the ongoing Mallorca series, but the final instalment of that one will be out in due course!
But first, a little bit about Nightjars. Their defining trait is that they feed at dawn and dusk, coinciding with when their primary food source, insects, are most abundant. They migrate to our shores for the breeding season, and stay with us from late April to September in order to raise their young, taking advantage of our mild climate and the abundance of insects at this time of year. They’re ground nesters, camouflaging themselves against the undergrowth with their incredibly detailed, cryptic plumage, and on Dartmoor they typically nest on heathland, or in young pine woodland, with the trees around 5-7 years old. They have a clever way of catching their insect prey, in which they simply fly around with their mouth open. This creates some often erratic flight patterns, and if it was your first time watching them you’d probably wonder what on earth they were doing. This is why they only feed at dawn and dusk, because they needs to be an abundance of insects or else their hunting method is not as effective.
Such a secretive, mysterious species has naturally featured in folklore through the ages. The Celts viewed them with awe, but also superstition, believing them to be the spirits of unbaptised babies, doomed to wander the night forever more. In Medieval times, there was a belief, began by Aristotle, that Nightjars drunk the milk of goats, causing their udders to dry up and for the animals to go blind. This, of course, isn’t true. Nightjars are only attracted by livestock due to the abundance of insects around them. But during these times when science and knowledge was less advanced, people would have certainly been afraid of the birds and the damage they thought they might do to their livestock. Then again, Aristotle did also say that Swallows hibernated in hollow places during the winter, so despite him being a great philosopher, take his teachings with a pinch of salt.
And how to survey them? Well, the group of Youth Rangers and parents, who had to be there due to the fact that this session was outside of normal hours, split into four, and headed off in different directions via pathways throughout the woods. There were two ways that we could identify a Nightjar as being present; by their call, or actually seeing them fly past. If we heard them call, we had to note down where we’d heard them on the map, as well as the exact time to the minute. If we saw them flying, we also had to note down the time, but instead of the ‘x’ we’d put down for a call, we had to mark the map with an arrow pointing the general direction the bird had been heading. We were doing a dusk survey, but Forestry England also operated dawn surveys at Brimpts Wood, from around 3:30 to 4:30 in the morning. I must say, I’m very glad we were doing the former! But all of this research and monitoring pays off, as Nightjars on Dartmoor are currently considered to be steadily increasing. So hopefully, these magical birds will be around for a long time to come.
Nightjars, if you can spot them, are usually very easily identified by their mechanical ‘churrrrrrrrrr’ call, which is very distinctive of this species. And gone dusk, you are unlikely to see anything else flying. But just in case, look for pointed wings and a long tail, almost similar to a falcon. As I’ve mentioned, their flight pattern is also very erratic when feeding compared to other birds, so look out for birds changing direction quickly, and flying in strange routes through the air.
Our group, led by Forestry England representative and Brimpts Wood expert Shaun, took the right fork, heading up a slope until the path levelled out and we could see all the way to Bellever Woods from our vantage point. It was fairly exposed up there, and the wind was whistling through the gradually darkening air. The problem was, Nightjars are much less likely to fly in windy conditions such as the ones we were experiencing, simply because their prey won’t fly either. A gust of wind may not seem like a huge deal to us, but to a tiny moth it can be a considerable obstacle. Before us, the slope was a very open woodland of young conifers, with plenty of cover on the ground for the Nightjars to conceal themselves and their nests in. Quite the contrary to the patch of woodland behind us, which was so dense that even I probably would have struggled to walk through it.
The wind, after about 20 minutes, started to die down slightly, and the insects decided to come out from their hiding places. I was just starting to notice an abundance of moths around me when an electrical ‘churrrrrrrrrrrrrrr’ started up. It almost sounded mechanical, like a clockwork toy quickly unwinding. Nightjars can call at 30-40 notes per second, which was clearly evident in this masterpiece of music from one of Britain’s most mysterious birds. It was exhilarating to hear such a thing in the night, but it stopped as abruptly as it had come. Suddenly, a phantom glided silently from a tree behind us, performing an erratic flight full of agile turns and dives. The Nightjar went on feeding, its prey caught off guard by an avian ghost. I watched in admiration as the bird came and went, as quick to disappear as it had materialised.
Nightjars are a relatively understudied species of bird, compared to most species in Britain. This is, in part, due to their nocturnal habits, which make them trickier to survey than diurnal (awake during the day) birds. Another reason is their cryptic plumage, which provides excellent camouflage against the ground, in a bush or upon a tree branch. But there are also concerns about surveys becoming too intrusive, as with all ground nesting birds. Unlike garden birds, for example, there is a risk with getting the public too involved as they may not have the expertise to avoid the nests or the birds themselves. So Nightjars are very understudied, but from what we do know, they seem to be steadily increasing on Dartmoor.
It seemed that as soon as that bird dropped back into the undergrowth, the wind picked right up. A light, drizzly rain began to fall on us, and we made the decision to head down the hill in order to escape the elements and hopefully see some more Nightjars. As I said earlier, Nightjars will not fly in windy conditions, so finding a more sheltered spot flew to the top of our agenda. In order not to skew the data, we decided to pause the survey there, and in the hope of seeing some more Nightjars, we headed back down the track, and this time took a different path, which led along the bottom of the hill we had been stood upon before. There we met another group, headtorches illuminating the gravel track. It was getting a lot darker now, and I hadn’t noticed how little light was left now. Of course, in this more sheltered spot, the other group had seen around a dozen Nightjars, and even as we walked towards them another ‘churrrrrr’ started up.
Suddenly, the birds were everywhere, emerging soundlessly from the vegetation. They scythed through the air, feeding on the wing like Nightjars possessed. It was a true spectacle, with as many as seven birds being in the air at once, all gliding rapidly past our heads, pursuing the moths that were now out in force around us. Their flight patterns were completely random as well. They weaved through the nighttime, whether in a zigzag or a loop the loop. It was breathtaking, standing in the darkness watching ghost-birds zoom about the woods.
But soon there came a time when all the Nightjars just stopped. We turned back at that point after we’d caught our breath back, but why don’t Nightjars just fly all night if they roost for most of the day? Well, one of the main reasons is that the insects just aren’t anywhere as near abundant as they are at dawn and dusk, and as I’m sure I’ve mentioned somewhere in this blog, the Nightjar’s feeding method (flying around with its mouth open) is not as effective when there are fewer insects in the air. So when they become less abundant, so do the Nightjars. Also, flying takes a lot of energy, and even during hours when the birds are most active, they still need time to rest and digest their food.
So if they fly at dawn and dusk, what do Nightjars do during the day? Well, the obvious answer is that they just roost. But it’s not exactly as simple as this. They still have eggs to incubate, and their cryptic camouflage allows them to do this even in broad daylight. Typically, the female is in charge of incubation duties during daylight hours, and the male comes in to take over during the night. So, you may just be more likely to see male Nightjars at dawn, and females at dusk (according to my logic, which is not, by the way, solid fact). Of course, being strict ground nesters, these birds are highly susceptible to disturbance, which was a reason for their previous declines. So, at this time of year, please make sure to keep dogs on leads and stick to paths when walking through areas such as these.
I feel so privileged to have had such an experience, which is up there with some of my most memorable birding moments. To experience such a secretive bird opening the door into its life, calling, feeding and flying around us, could not compare to little else. Soon these birds will be off again, migrating back to Africa in a matter of months. So let’s enjoy them while they’re here. Huge thanks to Forestry England and Dartmoor National Park for organising this event!
The Bovey Birder 