Recording Bird Calls
Now why would one become interested in recording bird calls when there are so many excellent and comprehensive recordingsavailable to buy? Often one's own efforts do not compare well with those made by professionals apart from the fact that one is reluctant to embark upon a field which appears to be fraught with difficulties. After all, recording good quality sounds is for the expert; or so we think.
I have become interested because I made a study of South African bird calls as a hobby as I found it exhilarating to walk in the bush, drive in a car on a country road or to lie on a bed in a game park early in the morning and then mentally tick off all the species I recognise. The amasing thing is that I have many "lifers" on my checklist which I identified by their call alone. Examples that come to mind are the Greater Honeyguide, Emerald Cuckoo, European Cuckoo, Willow Warbler - the latter two in Holland of all places- Scops Owl, Barred Owl, Mozambique Nightjar and many other species.
I decided to make my own recordings as I became frustrated by hearing a sound which I could not place even though I know I have heard it before. Well, I started recording those calls and listened to them in the comfort of my home and comparing them with commercial recordings. An unexpected bonus also arose from these recordings. When I played them back, the callers often appeared into the open to investigate. That gave me a chance to visually identify the species responsible for the call.
One does not need complicated and expensive equipment to make these recordings. I use a handheld 35 cm "Sony" parabolic dish equipped with a small solid state microphone. My recorder initially was a simple tape recorder eqipped with a microphone jack. Its light and portable and easy to operate. Although I was recommended to use a recorder with earphones attached to be able to hear what I am recording, I had problems locating a simple inexpensive one and gave up on it. Well, one can get along just fine without this luxury. Just point your dish in the direction of the call and you have it! My dish is transparent and I can at least look at what I am recording if the bird is visible. Later I was fortunate to obtain a minisdisc digital recorder with ear phones which simplified matters. (See Pictures below)
Now for the real fun part!
If your computer has a good sound card you can have a ball with your own recordings. By
transferring your recordings to your hard drive through the
"line-in" connection of your sound card and by using
the sound recorder of Windows or any other sound recorder program for that
matter, the call is digitised and
saved in a "wav" file format. But beware! These files
can easily become very large if you do not take care. It is not
uncommon to end up with a file as large as 5 megabytes if
the sampling settings of your sound recorder are set at
"stereo, 16 bit, 44 100 Herz". If you have a reasonably
good recording of your call, the size of the resulting file
can be reduced significantly by using a "mono, 8 bit, 11 025
Herz" setting without degrading the quality of the
sound to unacceptable levels. In fact, the recordings on
the "Roberts' Multimedia Birds of Southern
Africa", are all in this format. These original
recordings are of professional quality so do not expect to get a
similar quality unless your original recording is
exceptionally clear and free from noise. Also, there is no
need for a lengthy file to save a call. The sound recorder
has a facility to cut out unwanted sections of the
recording until you end up with a file of less than 100 kilobytes
in size lasting for only about 7 to 10 seconds and
containing the best part of your recording. Keeping files
small also makes it easy to attach them to e-mail messages to
your friends on the Internet.
Nowadays it is simple to compress wave files
to MP3 or WMA format so that the size of the original wave file does not
matter any more.
(click on images below to view larger pictures)
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If you have the necessary software available, you can open a wav file and the sound file appears as a sonogram in the window. You can view the graphical representation of your recording and can simultaneously open a recording from the same species directly from a CD like the one from Roberts' Multimedia. Both sonograms can now be compared by tiling the windows horisontally as illustrated. Creative Wave Studio, the one I used, also has a number of other useful editing features such as increasing the volume, cutting, changing the recording format, adding echo etc. etc.
Have fun!
(Click
on image to listen to the
"pretty
georgie" call of the Emerald Cuckoo)
Sonogram of the call of the Emerald Cuckoo (Chrysococcyx cupreus - Roberts' no. 386) recorded in the Knysna Forest in the Southern Cape. The only call that can possibly be confused with this, is the imitation call by the Chorister Robin (Cossypha dichroa - Roberts' no. 598). This is a resident species while the Emerald Cuckoo migrates to the North in Winter. So if you hear the call in Winter, it is produced by the Robin!
