Recording Natural History Sounds
A look at this interesting but often neglected aspect of recording wildlife.
Home recording is not limited purely to the recording of music; it encompasses a wider variety of subjects, one of which is wildlife recording. One practitioner of this intriguing art is Richard Margoschis who lectures on the subject, and in this feature, he outlines the techniques and equipment used in making recordings of wildlife sounds in the field.
For the past quarter of a century I have been using a studio which is available to anybody, at all times of the day and night every day of the year, and it is free of cost; the actors and singers are there all the time, and they have no interest in copyright! It is not without some snags, however, because the wide open spaces of the countryside that are my studio have no roof and no walls, and the wild animals that are my subject cannot be directed. My control room is at home but might be better described as a 'sound workshop' where the recordings are processed, though it is backed up by a motor-caravan which frequently doubles as a control room when on location.
It is all the result of an earlier interest in making 16mm documentary films for which I needed sound recordings from places where no mains electricity was available. At that time the only portable tape recorders on the market were outside my budget; so I made one. Based on the famous EMI L2, it was driven by a huge clockwork motor and weighed about twenty-five pounds! With it I made my first recordings of birdsong and became so interested that I dropped the filming and started to specialise in recording all sorts of natural sounds. That was over twenty years ago, and it remains my hobby today.
Somewhere around the year 1960, the Fi-Cord 1A appeared and I managed to find the £60 needed to purchase one; ½ track on quarter-inch tape at 7½ips and an overall weight of only four pounds - it was a gem! I was really mobile. Through the years since then I have used several portables, including the Tandberg Series II, and three of the four marks of the famous Uher 4000 Report family. But my pride and joy, now several years old, is my Nagra 1VS; at a bulky 16 pounds very different from the original Fi-Cord but much better than my clockwork effort.
Microphones, too, have changed. Twenty years ago my favourites were the Grampian DP4 and 6, and the Beyer M119. Now I use various versions of the Sennheiser MKH series of RF condenser microphones and cannot speak too highly of them; a pair of MKH 815 gun microphones with my Nagra 1VS is, I think, the ultimate for stereo recording in the field.
These microphones are very susceptible to wind rumble and it is quite impractical to use them in the field without a very efficient windshield. In locations such as moorland, for instance, there is usually at least a stiff breeze blowing and, with a subject that is producing a relatively low level signal, the record gain has to be that much greater, with the result that the slightest wind blasting will ruin a recording.
In extreme conditions some assistance can be given to the windshield by the use of a bass cut filter in the microphone line, but I use one only as a last resort. Some very good windshields are available but I prefer to make my own, not only because it is cheaper; they are designed for special purposes and several have double walls to allow an air barrier between the microphone compartment and the external air.
Although wind is such a problem it is also part of the habitat, in fact, it can add atmosphere - another dimension, and so I am always pleased when I am able to make it sound convincing rather than merely a background roar. That is not easy, and much will depend upon the way the wind is blowing onto the shields. Just as difficult is to make the sound of wind in trees, hedges, reeds etc. sound right, and in this case stereo can, I think, help. However, with a pair of microphones, each in its own shield, bunching can occur resulting, on replay, in wind sound to left and right and not in the middle. This is where my special windshields, built to contain a pair of microphones are a great help.
If wind is a hazard when recording in the field, then extraneous noise from the internal combustion engine in its various forms is an even greater one, and of these the small engines propelling small motorbicycles and chainsaws rank high. Railways, unless a very busy main line, are at least intermittent, whereas a motorway produces a continuous roar causing interference over a mile or more under good atmospheric conditions. Naturally, I try to avoid working in such areas but when that is not possible I bear in mind the fact that I might be able to do something about it later - during processing by using special filters.
With these extraneous sounds virtually outside the control of the sound recordist, considerable problems arise in respect of the balance or, as I prefer to put it, the signal-to-ambient noise ratio. Obviously, the proximity of the microphone to the subject is all important, but how do you get a microphone near enough to a wild animal and at the same time have regard to the Acts of Parliament which protect certain species from wilful disturbance. Some knowledge of the subject, prior observation, anticipation and a large amount of patience are the required attributes, in addition to a first class working knowledge of the equipment in use.
I am usually aiming for one or other of two principal types of recording; either an individual species or a habitat, and they are really very different. When recording an individual species, be it insect, bird or mammal, I aim to make the subject stand out from any other species which might be calling, but not to the extent that the others are inaudible because they must provide a background which is just sufficient to define the habitat in which the subject is living and if, as occasionally happens, there are no other animals calling, then I want some other sound - wind in trees, or a stream, for instance.
The habitat recording is quite different: here I am not dealing with only one species but attempting to portray all the species that live within a habitat, which can be anything from a few square yards of undergrowth to a river estuary half a mile across, and I want no one subject to be dominant for more than a few seconds at a time. 'Attempting' is the right description really, because rarely will all the animals present call within the few minutes for which a band can run. Invariably, when making this type of recording, I do very long takes and sort out the best parts at a later date.
As usual, there is an exception to this rule of balance between subject and background. It is usually broken when I am working in mono, as I frequently still do, and attempting to get the microphone close enough to produce a clean background. My reason for doing this is to obtain a recording of an individual species which can later be mixed with others and will not add any unwanted noise to a basic background atmosphere, often provided by a stereo recording made immediately afterwards.
That is a situation which calls for another very important piece of equipment - the parabolic reflector. Whether in use with an omni or uni directional microphone, the reflector is more directional than any other set-up, especially in the mid and high frequencies, and because the lift of some 12 to 15dB is achieved mechanically, it adds no system noise to the recording. It can be used to record most birdsong and the considerable improvement in the signal-to-ambient noise ratio means that good recordings can be made over a much greater distance.
Diameter and focal length are the two parameters which determine the shape, and therefore the size of the dish. For many years I have favoured a diameter of twenty inches and focal length of five inches; there are several reasons for this, not the least being the fact that whilst the dish is of adequate size for my purpose it can still be easily carried. Over the years I have developed the design and now manufacture and market the Atherstone Reflector Mk3, made in glass-fibre and light enough to use in the hand, though it can be mounted direct onto a tripod.
Although the majority of recordings are made while sitting or standing as comfortably as possible, and waiting for long periods within the habitat, there are circumstances when it can be a distinct advantage to work from the motor-caravan. Once the microphones are set up in suitable positions and the leads, which can be up to 300 metres long, run back to the caravan, no further disturbance of the habitat need occur for many hours.
Two examples come to mind. To record capercaillie, I set up before dusk and was then ready for a long recording session from before dawn until nearly midday without getting out of the caravan! The other occasion was when I found a stoat with kittens in the nest; I stayed there for twenty-four hours and came home with what I believe to be unique stereo recordings of a truly wild stoat with young.
Equipment in my workshop includes Revox A700, Phillips N4522 and Ferrograph Logic 7 studio machines for quarter-inch tape and a Technics three head cassette machine, together with Audio Developments Pico mixer (also used in the field), Technics equaliser and a special set of filters produced by Electro Sound.
After a successful field recording session I have to spend a lot of time going through each tape to take out the sections I want to keep which often runs out at 10 to 15 per cent of the recorded material but in some cases can be much lower. On one subject, for which I spent four days in a Scottish forest in October, I saved less than a quarter of an hour out of twenty-four hours of recorded tape! In the case of the stoat, three-quarters of an hour was saved out of six hours.
My library now contains nearly three thousand recordings of 213 British species, and a wide variety of habitats, nearly half being in stereo. From this collection I am able to build up programmes for many purposes, including my own commercial cassettes in the British Wildlife Habitat Series in stereo, and there is also a small demand from theatres, film and television producers for sound effects.
When I am building up a sound 'picture' of a countryside habitat, the detailed documentation of where and when each library recording was made goes a long way to safeguard against falling into the trap of mixing the calls of species which would not be present, or not calling at the same time in that habitat; inevitably, at some time, somebody will spot such an error!
Although so very specialised, recording natural sounds is like any other branch of the sound recording art - it can be taken to the degree desired by the individual; top quality with expensive equipment, or 'have a go' and make a start with equipment costing under £200.
For those interested in wildlife recording, more details of membership to Wildlife societies and design information for a 'parabolic reflector' can be obtained through Richard Margoschis, (Contact Details).
Feature by Richard Margoschis
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