Thanks for all the infomation on different recording equipment for bird calls. I have attached all the comments because there was so much interest from other listers. So please refer below.
MP3 is what is known as lossy compressed audio, it discards what humans can't hear, making it useless for most bioacoustics research. Most mid- and high-end recorders should allow to record in wave (.wav) format, which is uncompressed. MP3 files are compressed, and the compression necessarily loses some of the sound quality. Most people using recordings for analysis (say, with spectrograms) or for playback, if they're using digital formats, use WAV files. WAV files take up a lot more space than MP3 files, but that extra space is because MP3's are throwing out some of the data. As for equipment, there are a lot of compact digital recorders that are really good (that can usually record in WAV or MP3 or some other formats). I use a Roland Edirol R-09. For microphones, you can use either a parabolic dish microphone or a shotgun microphone. Parabolic are definitely better for recording quality (they isolate the target better and give a better signal-to-background), but generally more expensive and a lot less portable. I use a Sennheiser ME 66 / K-6 shotgun microphone. But the best recordists use big (up to 1-meter across) parabolic dishes with microphones designed for them. Cornell's Macaulay Library has a nice document that gives some detail on different brands and models of recorders and microphones. It's here: macaulaylibrary.org/documents/AudioEquipment.pdf I would get a second opinion, as I haven't made a point of recording birds with this device, but I use a Zoom H2 recorder, which records *.wav files (better resolution than *.mp3) and can be used as a stand-alone recorder, or can be used with an external mic. There are 4 channels (4 mics built-in), which can be set to record in surround stereo, or directionally (90 or 120 degree sweep) in two-way stereo. You can set the gain level to high, low, or intermediate (low if the bird is right there, high if it's quiet or far away), and there are built-in filters for field recording. It seems like parabolic mics and 'shotgun' mics are often used by people recording in the field - I don't know much about their use. That may have been helpful...hope it was! When I was recording gibbon calls for analysis in Vietnam, I was warned off using MP3 players because you lose information during compression of the data to the MP3 format. This was 10 years ago, though, so perhaps now theres a better option than the old-fashioned cassette tapes that were recommended to me at the time? I record birds on a small, digital voice recorder (suggested for use in meetings and so on) - and have made very good sonograms with those recordings. Almost all recorders describe the frequency ranges they record, so you can see which will get the range you want. More important would be the microphone. Ideal, a parabolic, next, a shotgun mike, but that will depend on the recording conditions. If you can always get close and hear well the bird you are recording, then it will be easy. If you are always far away in complex vegetation, that is another story - in bad conditions, better microphones become increasingly important. You may have already gotten your answers. The file format for mp3 players compresses the sound and you loose information. Basically it looses the frequencies that human ears cannot hear (or cannot hear well). Which is fine for us listening, but if we are trying to play it back and get other organisms to respond, it could be a problem. The best I have found is made by http://www.wildlifeacoustics.com/index.php However - they are pricey! The best equipment we are using at the moment is a Sound Devices 722 Recorder or a Korg M1000 Recorder with a Telinga Twin Science Parabolic Microphone. I would definitely recommend a parabolic microphone over a directional one as the difference in quality is stunning. We record at 16bit 44.1Khz. Yes never use MP3 player for your playback experiments if you want to get published as the sounds are compressed. We used either an ipod with a little portable speaker or lately we have been using FoxPro Scorpion playback systems which have a remote control and are much easier to use. I really recommend the latest. I have no first hand experience with recording bird calls, but do have audio experience. You are right that MP3 is not good for recording nature sounds. MP3 makes very small files by eliminating parts of the audio signal that will not be noticed when playing back music. What the human brain does not miss in music can make non-music recordings sound really bad. Birds would almost surely not be fooled. It would make frequency spectrum analysis of the recordings meaningless. Nature recordings often have audio frequencies that do not match human speech, so a good quality microphone is going to be important. Professional-quality microphones often have a frequency response graph. Look for one with a relatively flat response across all frequencies and one that has a wide frequency response. Good luck with the recordings. We have been using a Olympus LS-10 Linear PCM Recorder with a AudioTechnica AT 897 condenser microphone to record a variety of animal vocalizations successfully (including cranes and kiwis). We're saving the files in .wav format. The FoxPro playback gear is ~AUS $1000. http://www.king-cart.com/apc/product=/product_name=FOXPRO/keywords=/exact_match=/next=30/return_page= The recorder/microphone is more expensive ~4000 I think. http://www.sounddevices.com/products/722.htm The microphone is probably the more expensive bit (come from Sweden) but if you are doing recording at the nest only you can get away with a shotgun microphone (we use Behringer C2 condenser microphone that we placed directly under the nest http://www.behringer.com/EN/Products/C-2.aspx) They should not be too expensive. Which software do you use for transform/analysis? I used Raven and Amadeus Pro. In case other people have not already emailed you about this, the problem with MP3 files is that they compress sound in a 'lossy' way, throwing out information that human listeners cannot perceive. You should never record sounds to such a format if you want to analyze them later. However, many kinds of recording equipment allow you to choose what format you record to, so you can choose an uncompressed format such as .wav or .aiff. The best way to choose the equipment you will use to record a bird is to find high-quality recordings, such as from a CD field guide, make some spectrograms, and look at the frequency range of the sounds. Then, look up the frequency response of the microphone that you are using. The microphones that come with cheap digital voice recorders are often only able to faithfully record sounds up to 8-9 kHz. The digitizing equipment that you use will also impose some limits on what frequency ranges you can record, but generally much less severely. In my research, I use a pretty expensive Sennheiser microphone, but I have plugged it into a lot of things, including Sony cassette recorders, Marantz digital recorders, and battered old laptops running the free Audacity software. We are using SongMeter Model SM2 recorder which is made by Wildlife Acoustics. Our first recording calls are amazing, but of course it depends where about you have to place the recording system, and how hard is the noise around it. You can have a look on the SongMeter supplier website: http://www.wildlifeacoustics.com/index.php Hope this helps
