1. WHAT & WHY?
NocMig refers to the process of passively-recording nocturnal migrant birds, with a wide possible variety of sound-recording devices/setups, from very cheap and simple, to expensive and complex. Although passive-recording has been covered in the previous section, we decided that the complexities of NocMig deserve a space of their own.
Fortunately for us, many bird species call as they migrate at night, presumably to maintain contact between others of their kind, and ensure they are following a safe and/or accurate path. These vocalisations are popularly referred to as Nocturnal Flight Calls or simply NFCs, which is the term we will use hereinafter.
In northern Europe, the most famous example of a nocturnally vocal migrant is Redwing (Turdus iliacus). This northern thrush migrates south in vast numbers in autumn, as they escape the extreme winter weather of their breeding territories. They do this in search of milder conditions and a steady supply of food to see them through until spring, when they will migrate north, once again. Most people will have heard this NFC in late autumn whilst walking home in the dark, as birds pass overhead, sometimes in their thousands.
However, it is not only Redwing that call at night. No matter where you live, if you take up NocMig you are guaranteed to add totally unexpected species to your garden list. NocMig is full of surprises and has the potential to throw up anything.
For those of you not accustomed to NocMig, you might be surprised to learn that Common Moorhen (Gallinula chloropus) – a species of well-vegetated, freshwater wetlands is one of the most commonly detected NFCs by “NocMiggers” throughout Ireland, the UK and indeed many other parts of Europe, even over habitat-devoid, urban locations.
Another eye-opening NocMig discovery is that of the overland migration of Common Scoter through the UK and Ireland. The regular overland spring passage of this normally highly pelagic duck came as a big surprise to many. Would this have been discovered without the widespread practice of NocMig in the UK? Probably not! To read more about this amazing discovery, click here and here.
NocMig in a European context is still in its infancy, relatively speaking. There has been a great deal of work done by the likes of the Sound Approach Team, in particular, to popularise NocMig, but there is still plenty to learn and discover, not only in a European context but in local contexts too. Are you curious to know what’s moving over your garden at night? You should be! NocMig is really exciting stuff, so let us take you through the basics to get you up and running. Follow through with our methods, tips and tricks and end it with a fun, interactive NocMig exercise, and get yourself NocMig-ready.
2. WHAT DO I NEED?
NocMig can be done with the simplest of equipment to get yourself started. Let us run you through some of the most common devices and setups so you can decide which suits you best.
If nocmig is something you’re not sure you’re going to like long-term then you can begin with simply using an old mobile phone, set out on record. To keep this dry, you can place it in a ziplock bag, or an upright container with some cling film stretched tight, kept in place with an elastic band.
Listen below to a very brief, yet perfectly identifiable recording, made by Cork-based sound-recordist Brian Lynch, of a Common Scoter migrating overland, at Glanmire, just outside Cork City. Just a few years ago, before NocMig really came into the spotlight, if anyone told you, that you could record Common Scoter flying over an inland, suburban garden with an old mobile phone, you’d have thought they were crazy! But as Brian shows, it is in fact totally possible!
The next step up is the tiny but amazingly versatile Audiomoth. This is a matchbox-sized device which can be programmed to turn on and off at whatever times you choose. The battery life is extremely good, with devices capable of running un-manned for up to several weeks or even months. To protect it from the elements, you can simply place it in a small Ziploc bag (see image below). Whilst the quality of the audio isn’t as good as a handheld recorder or parabola setup, the versatility of the device more than makes up for this. A second version has just been released (Jan’ 2021) onto the market which allows one to combine it with an external mic. This will be a big game-changer for NocMiggers on a budget. Combining the new Audiomoth with the Clippy EM272 (mentioned in more detail below) would work very well for nocmig.
For those of you who would like to do some basic sound-recording in the field, as well as NocMig , then a simple handheld-recorder is the answer. We use an Olympus LS-12, which is now unfortunately discontinued. However, don’t worry – there are plenty of comparable options on the market, with the Zoom range, in particular, proving very popular amongst NocMiggers. A common NocMig tactic when using a handheld recorder is to simply put it in an upright pot, sealed with cling-film and an elastic band. Both of these combined, protect the device from the wind and rain, with cling-film still being sufficiently sound-transparent to avoid any real noticeable deterioration in sound-quality.
People have created various homemade devices, where they combine mics with a handheld recorder: some of these work very well. One good option is to buy a simple Clippy EM272 which you can get for as little as £35 here. The EM272 is a low-noise, high-sensitivity omni-capsule which produces amazingly clean audio. You can combine the Clippy with any manner of MacGyver-esque setups to create your very own DIY NocMig-station.
See below for a perfect example, by Irish NocMigger and sound-recordist Mark Shorten. Here Mark combines a handheld recorder with a Clippy EM272, which is pointed to a metal dish, which in turn acts like a parabola – amplifying the sound. Whilst it doesn’t look all too pretty, Mark’s audio sample (below) speaks volumes.
If you want to get the best out of your NocMig recordings and take your field recording seriously, then a recorder and parabola setup is for you. A more serious external microphone such as the Sennheiser ME66 could also be an option here, although a parabola gives even further reach. We highly recommend Dodotronic who make extremely good parabolas at a price that is almost impossible to beat. As well as this, their customer service and delivery speeds are second-to-none. We use a Dodotronic Hi-Sound Stereo setup and swear by it. Have a listen to some of our favourite NOCMIG recordings taken with the device, below.
3. HOW DO I DO THIS?
So, you’re toying with the idea of NocMig and maybe you have a fair idea what route you want to take device-wise. Maybe you already have a device but are looking for advice on how to proceed. Well, keep reading and we will do our best to help you proceed, with this no-frills, step-by-step, practical guide. We will take you through everything from software, analysis, database management, as well as post-processing techniques and more. It isn’t at all overly complicated and once you have a practiced routine it becomes second nature.
STEP 1. Preparation
Depending on what setup you’ve decided to go with, there are a number of steps you can take, before placing it outside to ensure your recording will go as smoothly as possible:
- Ensure your batteries are fully charged (you’d be surprised how many times we’ve put out half-charged devices, only for them to fail halfway through the night).
- Ensure that your memory card is formatted before use, each night. Deleting files does not necessarily mean the card has truly been emptied, and can result in recording malfunctions.
- Keep an eye on the weather – try to avoid excessively windy or rainy nights. Birds don’t tend to move much and you’re putting your equipment at risk. Some rain is ok, and can in fact be very productive.
- Make sure your equipment is protected from the rain, in the event that a sudden shower does occur during the night. Remember – you’ll probably be snoring when this occurs, so you’ve got to get this right beforehand! Cling film works well in keeping your equipment dry, although it does create a slight echo. If you have an overhanging ledge or parasol, then these are excellent alternatives.
- Think carefully about where you place your device. A very simple but effective piece of advice was gifted to us by Magnus Robb, of the Sound Approach: before you place a device somewhere, simply place your ear there to see how it sounds. Sometimes a foot to the left or right can mean the world of difference.
- Be aware of animals. We have had several devices chewed (badgers), stood on (wild boar) and dropped from a height (jackdaws). Sometimes they survive, sometimes they don’t. Try to avoid the risk.
- Likewise, beware of humans or your equipment may walk!
- The best pointing-angle of the mic/parabola is debated by many, and really we don’t think it matters hugely, within reason. We usually point our parabola at a 45-degree angle. In spring, we point south and in autumn we point north, but again, this doesn’t make a huge difference.
- To record within true NocMig hours, as defined by the Protocol for Standardised Nocturnal Flight Call Monitoring, set-up your device to record between civil dawn & civil dusk.
- With these points in mind, place your setup outside and the process begins!
Step 2: Software
It’s morning time – you’ve had your cup of coffee and you’ve collected your setup from outside. It’s still running, it’s dry, and no animals have chewed on it. What to do now?
You’re going to need some software to upload, view, and edit your audio files. Luckily for you there are several free, excellent options available to download online. Viewing your audio in spectrogram form (see an example of a spectrogram below), means that you can, with practice, scroll through your 9 hours or so of data with ease, visually looking for NFCs as you go. This means that you can easily go through your files, depending on how busy or quiet it was, in about 30 minutes to 1 hour.
To do all of this, we personally recommend Audacity. It’s free, very easy to use and works very smoothly. RavenLite is another popular option but we find it a little bit more finicky, although it produces very nice spectrograms, which we often use for publications. For the sake of this demonstration we are going to work with Audacity.
To proceed, click here to download your free version of Audacity.
Step 3: Uploading and Preparing Files
You’ve installed your shiny new Audacity software – what now? From here on in, we’ll switch to videos, so we can demonstrate in a more engaging manner.
Step 4: Extracting & Entering Data
Now that you know to to open and adjust your files with Audacity, let’s take a look at how to find, and document your NFCs.
Step 5: Cleaning & Saving Files
You’ve come across a very clear NFC, and you’d like to cut it, clean it and save it for your collection. Let’s see how we can do that!
4. NOCMIG PRACTICE – with a genuine 3hr sample
To put all of your skills to the test, we have uploaded a 3hr 22m sample of very busy nocturnal migration, recorded Oct’ 2020, in Catalunya, for you to work and practice with.
Please click ——> here to download from our Google Drive account.
This was one of Seán’s favourite nights of nocmig from Autumn 2020, and even if you are an experienced NocMigger, we recommend you download and give it a try – you’re sure to enjoy it!
A summary table of the species, including an estimate of the numbers of individuals, as well as the total number of calls/species is available upon clicking the button below. Try not to click this until you have analysed the recording for yourself. We recommend you give yourself at least 30-45 minutes to do this. Take your time, making sure not to skip past the more distant, fainter NFCs. Feel free to practice extracting, cleaning and saving audio files from within- enjoy!
PS: Seán makes a cameo or two as he was sitting out and live-listening – marking some of the more interesting species vocally, for review the following morning.Reveal Answers