(Common Sandpiper sonogram image © Harry Appleyard)
In 2017, having already vigorously covered the Tattenhoe area in birding and photography of other wildlife for nearly 10 years, I started to share my local findings and records more widely with other local birders and field naturalists. Through social media with such like-minded people, I was introduced to the concept of ‘nocmig’, the recording of nocturnal migration in birds through sound recording.
Aside from late evening walks occasionally producing wintering thrushes and the odd wader or two, this was very much uncharted territory for me but with a goal to record as many bird species in and around the Tattenhoe area as possible, it was something that I was keen to investigate further. Findings by others, like Bitterns and Common Scoters from the comfort of their own homes, made it all too exciting to resist.
As with wildlife photography, there are countless ways in which nocmig can be carried out. In 2020 I went for a fairly simple setup: a Tascam DR-05 sound recorder left running overnight on a small tripod in a bucket, placed in the middle of my garden. Providing temperatures kept near or around double figures with no precipitation, the recorder would usually run all the way through the night until I would pick it back up the next day.
Recording and reviewing sound recordings (in brief)
After retrieval, the recordings are imported and amplified in Audacity, a free piece of audio editing software, which provides a visual representation of the audio known as a spectrogram or sonogram. No single night is ever without the sound of traffic here but as the time progresses towards midnight and into the early hours of the next day, a much calmer suburban soundscape allows for fleeting calls and vocalizations to be at their most detectable, forming bold dots and streaks.
Picking out calls from late at night and into the early hours is usually quite easy even on brief scroll-throughs of the files (when magnified). However, singular flight calls or those of more distant birds can be very easily missed, so the recordings are always worth giving careful review, especially during the peaks of migration in spring, late summer and early autumn. In spring and summer, Blackbirds and Robins gently start off the dawn chorus, adding a few more consistent patches of song into the spectrogram, which gradually progresses into a more jumbled, convoluted collection of multiple species combined with increasing traffic noise. Trying to find the vocalizations of scarcer species in such high activity within the immediate area can be a gruelling process but patience can be rewarded in listening out for unusual early daytime flyovers. Even familiar species can make odd-sounding calls in the night but websites like Xeno-canto.org focusing on vocalizations can be a great help.
The species
Coots and Moorhens, especially the latter, are familiar sights on daytime walks in Tattenhoe and around the city’s larger waterbodies. Sticking close to their freshwater homes, their flights in the daytime are usually short distance, seeing off others from their territories or evading potential threats. By night however, they have become surprisingly regular garden birds for me in these recordings, in the flyover sense. With 11 recordings so far, Coots have been detected passing by the recorder as early as 20th February to 14th July. As with the Moorhens, it’s likely that late winter and early spring records involve birds departing from wintering flocks to head for breeding grounds elsewhere, while records further into the spring and summer are more likely to involve local breeders patrolling their surroundings. Another species I’d never expect to see over the garden in the daytime, the more elusive Little Grebe, has also been detected several times between early June 2020 and late February 2025.
(Coot recording and image © Harry Appleyard)
Aside from the odd Mallard, Greylag and Canada Goose, other waterfowl have had little presence on the audio, but Common Scoter was a much-hoped-for target species achieved, with several calls caught at around 1.35am on 22nd March 2021, coinciding with their seasonal cross-county movements by night. Waders of any kind are always a treat in Tattenhoe these days. With the exception of the graceful, slow-flying Lapwings, record shots of them in flight are usually the best means of illustrating their often fleeting appearances here but nocturnal migration recordings have offered much clearer means of documentation.
Oystercatchers have made few-and-far between appearances on my daytime walks across the Tattenhoe area, though nocmig has increased their recording rate here, ever so slightly. Two years after my previous daytime record, one was picked up calling just before 1am on 5th April 2020, another at 01.13 on 15th June 2020 and lastly in 2023, a single call at around 03.47 on 18th July. Golden Plovers have been scarce autumn and winter flyovers, with 3 nocturnal recordings adding to a handful of patch records. Several of their calls were picked up between 23.00 and 23.20 on 9th and 11th October 2020 and more recently, several more just before 20.00 on 19th March 2023, which is currently my latest winter/spring date for them here.
(Golden Plover recording © Harry Appleyard)
Both Ringed Plover species have also joined in on the action, with the largest of the two being an entirely new Tattenhoe bird for my records. Exactly a month after one flew fast and low through Tattenhoe Park, two calls from a Little Ringed Plover were caught at around 1.34am on 15th July 2020. Much more recently, the sombre-sounding Ringed Plover provided two August records, with four calls picked up around 1.53 on 23rd August 2023 and almost a year later, two calls at around 2.20 on 11th August 2024. Another one of the much scarcer daytime flyovers here, Curlew, kindly provided a single loud and clear call at around 23.21 on 10th August 2023.
(Curlew recording © Harry Appleyard)
Preferring the larger lakes and wetland sites of the city, Common Sandpipers haven’t exactly lived up to their name in the Tattenhoe area with only one previously seen in the daytime in 2016 and one heard over Howe Park Wood on the night of 25th August 2018 – but in just three weeks in 2024, nocmig added three additional records. A single call was caught at 01.42 on 24th July, a series of overlapping calls undoubtedly from multiple birds around 01.15 on 12th August and another single call the next morning at 02.33. Strangely, Green Sandpipers which have produced several more daytime records here, including some grounded individuals, have alluded the recordings so far. The highlight of 2024’s nocturnally moving waders came in the form of a Dunlin, another all-new Tattenhoe bird for me, making a single call at 04.07 on 11th August.
Aside from Redwings and presumed continental Song Thrushes and Blackbirds arriving in the autumn, passerines have contributed very little to the recordings outside of the dawn choruses, though there have been a few birds of note well into the night. A Blackcap was caught giving a short burst of song nearby at 23.49 on 14th April 2020 and just over a month later, interestingly a Lesser Whitethroat was also caught briefly singing just after midnight on 21st May, at a time when none seemed to be holding territory nearby, so perhaps a late-moving migrant? A Dunnock also gave a single burst of song at 01.17 on 1st May 2021. One of the area’s scarcer passage migrants, the Tree Pipit, was recorded twice on 24th August 2023, with calls at 01.05 and 02.02.
(Tree Pipit image and recording © Harry Appleyard)
Along the way, two of the city’s more elusive and cryptic species have also made themselves known by sound. Tawny Owls have been perched nearby and calling on several occasions, while the Water Rail has been caught in passing, making an unusual late spring record with two calls caught at 00.41 and 1.53 on 31st May 2021 and an autumn record with a single call at 00.52 on 22nd October 2023.
(Nightjar recording © Harry Appleyard)
One of the personal highlights so far was the first Quail I’ve recorded in any capacity, calling loud and clear as it passed over at 2.47 on 28th May 2023 but easily the biggest surprise of them all was one of the earlier findings, a European Nightjar “churring” in the dawn chorus on 31st May 2020. On the sonogram, its song formed large thick bars, which I thought were probably a helicopter until I pressed play, completely and utterly failing to contain my excitement when I realised what it was. This was in fact my second record of the species in the Tattenhoe area, only a few months after filming one hawking around an oak tree on the late autumn date of 2nd October 2019 but I never thought I would get another one so soon, let alone singing in the vicinity of my own house. It seemed to sing nearby for about 4 minutes but was not found again in any subsequent recordings, so presumably another passing migrant, rather than a fully territorial bird calling my garden home for the season.
Conclusion
So far I’ve been blown away by the results from these recordings. While being in a landlocked area means it is more a case of quality over quantity, even in the best of nights, nocmig has generated records of species I never even thought I would see or hear from the comfort of my own home (if I was awake at the time!). Amid the rapid expansion of MK and changes to the local landscape not far from home, it’s provided some reassurance that there is still huge potential in the array of species coming and going locally.
Unfortunately I haven’t been able to record on anywhere near as many nights as I would have liked to, mainly due to weather or simply forgetting to recharge the batteries (doh!), but it is something I’ll definitely stick with into the future, whether I am in Milton Keynes or further afield. If you’re also a keen patch birder or just curious as to what you might catch in the night, I highly recommend giving it a go!
Harry Appleyard
February 2025