First published at https://www.benlocke.co.uk/2020-nightjar-season-summary-part-1/.
Part 1 – May-June
When the 2020 nightjar season got underway, Britain was in Covid-19 lockdown. Consequently, with everything I had planned cancelled, and with little else to work on, I decided to switch my daily ‘exercise’ to the evenings and start looking for nightjars early. Given that much of the project is concerned with bioacoustics and the need for good conditions for sound recording, we tend to notice the unwanted background noise of aeroplanes overhead and the drone of cars elsewhere in the forest. In early May this year though, the forest was truly quiet. Flights were essentially grounded and the only traffic was the very occasional ambulance or key-worker. Perfect conditions for listening for nightjars!
Before getting on to the subject of the Nightjars themselves, a few notes on other wildlife sightings that were had along the way. Roding woodcock are an ever-present sight and sound at every nightjar site around the forest, particularly during the first half of the nightjar season. Unusually, on the 24th May I was able to watch one feeding on insects (presumably) that it was picking from the gravel forestry track. Later that same evening I quite literally bumped into a boar piglet, or more accurately, it bumped into me. I’d already made way for the mother and her piglets which were crossing in front of me, and having already seen them twice that evening, I knew to expect no more than 5 piglets. After counting 5 across I continued walking, only this time there was a 6th lagging way behind, which likely mistook me for its mum as it crashed into my legs trying to catch up with her. On 19th May on the drive back home I had an unconfirmed polecat cross the road in front of me. Having seen many Scottish Pine martens, on the 24th June I saw my first ever English marten as one crossed the road close to home as I was driving back, and earlier that same evening I had an equally unlikely mammal sighting as a mole crossed my path as I walked to one of my sites in daylight. In another first for me this year, just as I was leaving the house one evening, I saw swifts mating in flight.
On the 2nd May I heard my first nightjar of the year. It was at 8.40pm at the closest nightjar site to my home. This is an early record. My first bird of 2019 was 10th May. Just a couple of brief flight calls, nothing more and no sighting. The same thing would occur a couple of days later at a different site. My third bird (and first proper sighting of the year) was on the 11th May. I’d already made 2 or 3 unsuccessful visits to that particular site but it’s long been a favourite place of mine and a reliable place for a pair of birds I’ve spent a lot of time watching over the years and I was eager for them to return. It seemed like it was going to be another no-show. At this early stage far more sites were unoccupied than occupied, so not seeing a bird wouldn’t be a surprise. Just as I was about to head back home, a male nightjar flew right past me along the track in silence. It came back and circled me, then landed on the track only a few metres away from me. We looked at each other, then he flew away, low along the same track. This was my first sighting of the year and one of my most memorable.
From that point onwards, birds started to arrive at nearly all of the usual territories. I was pleased to see the site closest to home was once again going to host two pairs. It also seemed highly likely that one of the two males was a bird that was well known to us (previously ringed and radio-tagged) as it was using all the same song perches. This was later confirmed with audio analysis. Female birds seemed a bit thin on the ground for longer than usual this year, but at this site at least, the 2 males had already found partners. Around mid-June it seemed there may have been a later influx of females.
By the 19th May I’d visited 10 sites and on 7 of them I’d managed to locate 11 birds in total. Lockdown rules had started to be relaxed and I was now able to meet up with the other members of our very small team, whose numbers have increased by 1 this year thanks to the welcome addition of a university student. On the evening of the 19th, and for the following days, one pair gave me some good clues as to where they might be intending to nest this year. However, another pair at the same site also had similar plans, and I got the impression that the two pairs were too close together. Most evenings all four birds would end up interacting, chasing each other around, and generally not getting on. In what seemed to be a last-minute change of mind, the original pair I’d been watching focussed their attentions on a different area. After giving them a few days I went to have a look in the early evening and found my first nest of the season, containing two eggs.
As we approach the end of June, I’ve visited at least 15 of the sites in the forest, many of them repeatedly, in the evenings. There are still many more sites left to check in person, but this year we’ve also made plans for a lot of the time-consuming work to be carried out automatically and without the need for evening visits. Last year we trialled the use of programmable audio recording devices to monitor for the presence of nightjars. This was successful, so much of our surveying this year will be carried out remotely. These devices will simultaneously cover almost every known and potential nightjar territory, and those that aren’t covered will be covered by visits in person. Using audio analysis it is possible to not only identify individual birds from the resulting sound recordings, but in theory, we’ll also be able to build up a picture of their movements through the forest, at least to some extent.
As with previous years, this year we intend to attach radio-tags to a small number of birds. These identifiable birds give valuable data to the research we’ve been doing. In addition, this year we also intend to take buccal swabs for DNA samples to contribute towards a national study of nightjar population genetics. Restrictions brought about by Covid-19 mean that for one reason or another we’ve been unable to make a start on this work until now. We’ve got a lot of catching up to do!
Hopefully in part 2, at the end of the season, I’ll be able to provide an update with regard to the radio-tagging, the results of the audio recording that is taking place across the whole forest, and an update on the overall numbers of birds in the forest this year. What I can say at this stage is that all the sites that I’ve visited this year (so far) that I would expect to hold nightjars, do. I’ve also found birds on brand new habitat that hasn’t had birds recorded on before. There are one or two sites that really are past their best as far as nightjars are concerned, and whilst they may not have nightjars any longer, this is to be expected. I think there’s probably more newly created habitat than lost habitat for the size of the Dean’s population to be negatively affected.