| FAQs |
Detection distances vary with frequency and loudness (amplitude) of the bat calls, atmospheric attenuation, the directional characteristics and sensitivity of the bat detector. It is also affected by the amount of structural clutter (obstacles such as vegetation) which can block the path of the signal.
The frequency and amplitude of the bat call has a major influence on how far away the call can be detected. This makes some species easier to detect from afar than others. Quiet (low amplitude) bat calls are more difficult to detect than loud (high amplitude) calls. Call amplitude can vary within an individual (as many bats will reduce the amplitude of their calls as they approach prey or clutter) and also vary between species. Species which always produce low amplitude calls (“whispering bats”) will be more difficult to detect from a distance than other species. In addition, bat calls of higher frequencies cannot be detected from as far as those of lower frequencies. Higher frequencies are often absorbed by the atmosphere (attenuate) faster than lower frequencies.
How quickly sounds attenuate in the atmosphere depend upon weather conditions such as temperature, humidity and air pressure. This relationship is complex, but in general, cool dry conditions will allow the detection of bat calls over greater distances.
The sensitivity of the detector also has a major influence on detection distance. While there is always some variability in sensitivity among units, the biggest influence is the setting of the sensitivity control.
Given all the above, it is obvious that detection distances will vary enormously. Many bats are easily detected over 30m under typical conditions, while some species which call at low frequencies may be detectable from as far as 100m. However, some species will be hard to detect from even 1m away. This is why only relative rather than direct statistical comparisons of bat activity are made between species.
Further information on detection distances and the calculation of detection fields and distances can be obtained from Chris Corben’s AnaVolumes software and the associated manual (http://users.lmi.net/corben/Beta/).
We no longer make Australis receivers, radio tags, collars or yagi antennas. We do still supply radio-tracking accessories including chargers, car chargers, and battery packs. We no longer service Australis receivers and yagi antennas.
Typically, a directional microphone will detect a bat from further away, but only directly in front of the detector. An omnidirectional microphone will detect a great volume around the microphone.
Which microphone is best depends upon your recording requirements. For example, a directional microphone may be best if you are recording a reference call and only want to record that particular individual in flight, or if you are conducting an active transect with spotlighting where you can follow the bat with your detector. An omnidirectional microphone with a cone may be best where you are performing a walking transect and you do not want footfall noise. An omnidirectional microphone may be best where you are performing a passive survey where there is no clear flyway. Speak to your local distributor about which microphone may suit your needs best.
The advantages of full spectrum include the ability to see intensity, harmonics, multiple bats calling at the same time, and faint bat pulses during high ambient noise. The disadvantages of full spectrum are that they are much larger files (typically 6 times the size of a zero crossing file), they require more processing power to record, and are slower to render on a computer for post-recording analysis. The advantages of zero crossing analysis is the small file size, so memory space is not an issue, and many published guides to bat calls are based on zero crossing analysis. The disadvantages of zero crossing are that spectral information is lost (which may be helpful to species identification), and that in cases of high frequency ambient noise (eg. insects), bat calls may not be recorded fully.
It is important to note that post-recording full spectrum files can be converted to zero crossing, but zero crossing files cannot be converted to full spectrum. Deciding which recording format is best will depend on the aims of your survey, the recording environment, and your data storage budget.
There are a number of file types used by Titley Scientific detectors. The Ranger, Chorus, Walkabout and Scout can record in either full spectrum (.wav) or zero crossing (.zc), you can select your recording format on the detector. The Walkabout additionally allows you to record both formats at the same time. The Anabat Express (no longer available) records zero crossing analysis files in .zca format, which records one file per night. The .zca can be split into individual .zc files using Anabat Insight.
All Titley Scientific detectors now save metadata in the GUANO (Grand Unified Acoustic Notation Ontology) format. This format is now the standard across bat acoustic fields. GUANO is also supported by the Anabat Insight software package.
On our passive detectors, such as the Ranger and Chorus, there is a Night-Only mode. This mode uses the built-in GPS to determine your location, it then calculates the sunset and sunrise times, and will automatically record from 30 minutes before sunset, until 30 minutes after sunrise. It will continue to record in this mode until the batteries run flat, the card/s become full, or you turn the detector off. This mode requires a GPS fix when first deployed, so be sure to make sure the Check LED on the front of the detector has stopped flashing to indicate the detector is ready to deploy. You can also use schedule mode to manually specify a location, for situations where GPS is not available.
On our passive recorders (such as the Ranger and Chorus), you can choose from Night-Only Mode, Continuous Mode, and Schedule Mode. These modes refer to when the detector is active and ‘listening’ for audio triggers. You choose between Night-Only, Schedule and Continuous Mode using the button on the control panel. Continuous Mode will keep the detector awake (day & night) and ready to record whenever a trigger event occurs.
Constant Recording is a different feature which can be used in conjunction with any of the operating modes listed above. This feature can only be turned on using the Settings Menu or through a schedule set up in Insight. Constant Recording will constantly save files to the card instead of waiting for triggered events. For example, if the Chorus has been configured to record from 6pm to 6am, with Constant Recording on, each night will result in a full 12 hours of files being recorded. The recorder will automatically create a new file as soon as the maximum file length has been reached, so as soon as one file ends, another will begin. This can be used to record soundscapes, or to record everything where there is a particularly quiet species of interest.
Constant Recording mode is generally only recommend for acoustic/audible sound recording, as the data volume for ultrasonic recording can be immense.
This will depend on your survey aims, however there a few general pieces of advice:
Mount the microphone pointing horizontally to prevent water droplets hitting the microphone element. Such water droplets generate large amounts of noise and can block ultrasound signals from reaching the microphone until they dry out. This needs to be considered when you are analyzing your data. Sensitivity can be reduced by inclement weather. Do not let heavy rain land directly onto the microphone element. The impact force of the raindrops can permanently damage the sensitive element, reducing its sensitivity.
Mount the microphone at a ‘flyway’ if possible (and if not contradictory to survey requirements). A flyway is a corridor where bats will fly through or beside vegetation, such as a track or open gully. Do not point the microphone across the flyway, but instead pointed along the flyway, this will increase your chances of recording a longer, high-quality pass.
Unless specifically required, do not mount a detector directly at a dam/lake. Bats will often change their search phase calls when approaching water to drink, so species analysis may be more difficult. If water is rare in the area, many individuals of multiple species are likely to drink at the water source each night, these datasets will likely contain confounding social calls, and individuals shifting frequency in the presence of conspecifics. Additionally, the water if flat will create a lot of echoes, if turbulent will create ultrasonic noise, and will likely be home to a multitude of noisy insects. Instead place the detector (if possible) along the flyway approaching the water source, or further back from the water’s edge.
Mount the microphone on an extension cable (if possible) away from flat surfaces. This is especially important if using the omnidirectional microphone. The omnidirectional microphone will record echoes from the surface of the detector if mounted directly to the detector, the same will occur if the microphone is placed next to a large flat surface. If possible, mount on a pole or small post/tree.
Windy, dry conditions can result in electrostatic build-up which may damage the microphone. Also, be aware that mounting your microphone or detector on a tall mast may attract lightning. To minimise the chance of electrostatic damage isolate the detector from ground, i.e. operate it from internal batteries or make sure the external power supply doesn’t have a path to ground. In dry conditions avoid mounting microphones on tall non-conductive masts (inc. fibreglass and nylon), wood or metal masts are preferable. Ground the microphone, either by making sure it is clamped to a properly grounded metal surface directly (metal to metal contact), or by attaching an earth wire to the body of the microphone (e.g. with a hose clamp) and then connect that wire to a grounded surface (e.g. metal mast or ground stake).
For more information on mounting, placement and weatherproofing considerations, see your detector user manual.
Unless you are using constant recording mode, your detector will not be constantly saving files. It will rely upon triggers to decide when to save a file. These triggers can be adjusted by the user to optimize the detection of bats based on local conditions/species. Trigger settings include sensitivity, minimum trigger frequency, maximum trigger frequency, minimum event time, and trigger window. You can set all the trigger settings on the device.
Please see individual user manuals for explanations on trigger settings and how to adjust them.
When you have a multi-channel detector (a detector that can have multiple microphones), there is a lot of new terminology to understand what you can and can’t record.
Mono – Mono recording is recording one file from one microphone. This is how traditional bat detectors (like the Swift) work.
Stereo – Stereo recording is recording one file from two microphones. The recording will have multiple ‘channels’, which are slightly different depending on the microphone placement (one microphone will be closer to the sound).
Dual – Dual recording is recording multiple files from two microphones, but not simultaneously. For example, you can record ‘file X’ from the acoustic microphone at 5pm, then record ‘file Y’ from the ultrasonic microphone at 6pm.
Simultaneous – Simultaneous recording is the ability to record multiple files, from two (or more) microphones at the same time. For example, you can record ‘file X’ from the acoustic microphone AND ‘file Y’ from the ultrasonic microphone at exactly the same time. The Ranger is the only detector on the market that can record acoustic and ultrasonic simultaneously.
Acoustic and ultrasonic refer to generally accepted frequency ranges. Acoustic is recording audible sounds (eg. bird calls), whilst ultrasonic is recording high frequency sounds (eg. bat echolocation). There is some overlap between acoustic and ultrasonic frequencies. Acoustic generally means between 20Hz and 20kHz, whilst ultrasonic generally starts at 10kHz, extending beyond 250kHz. Microphones are designed to either record acoustic or ultrasonic.
Sample rate refers to the number of ‘samples per second’ taken during recording, measured in kilo samples per second (ksps). The recommended sample rate should be at least double the highest frequency of interest. For example, if your highest frequency bat echolocates up to 150kHz, then your sample rate needs to be above 300ksps.
The default sample rate for acoustic recordings is 44.1ksps. A suitable sample rate will depend on the frequency of the sounds being recorded, it needs to be at least double the highest frequency sound you want to record. For example, since koalas make low-frequency sounds, a sample rate of 22.05 or 32ksps is often used. For best sound quality, a sample rate of 44.1 or 48ksps is recommended.
The gain setting is how much amplification is applied to the signal. A higher gain setting will pick up sounds from further away, but at the cost of distorting loud or close sounds by over-amplification. Conversely, a lower gain setting is used to record sounds close to the detector that are expected to be fairly loud. A gain setting of +12dB is a good starting point for general applications.
TrOUBLEshooting / Product Specific Questions:
Ranger & Chorus
The Chorus comes supplied with a low-profile acoustic microphone, which will have a wind sock attached. The acoustic microphone will be underneath the cardboard insert in the box below the detector. If you purchased an ultrasonic microphone, this is also a low-profile ultrasonic microphone and will be pre-mounted on side B (the hinged side) of the Chorus. The acoustic microphone can be mounted on either side, whilst the ultrasonic microphone can only be mounted on side B.
If the Check LED is flashing without the magnet applied, it means there is an issue affecting deployment. Do not deploy until you resolve the issue. To check the issue/s, open the case and look at the status message/s on the dashboard.
Common issues that need to be addressed include locked SD cards, no GPS fix and no microphone detected for the recording settings chosen.
On the Ranger you can record ultrasonic and acoustic at the same time (even stereo acoustic).
On the Chorus you are unable to record ultrasonic and acoustic simultaneously, however you can create a schedule to record ultrasonic and acoustic during the same deployment. For example, you can record acoustic through the day and ultrasonic through the night.
When recording in full spectrum, if you find that your spectrogram has excessive echoes (“messy”), it is likely due to echoes from where the microphone was mounted. We recommend that you mount the recorder away from any flat surfaces (such as boxes or walls). This will produce much clearer recordings.
Accessories to mount the microphone away from the recorder will also help avoid this problem, and can be purchased from Titley Scientific. A gooseneck accessory on the Chorus, and a microphone extension cable on the Ranger can be used to mount the microphone away from the surface of the recorder itself.
While these recorders are designed for passive monitoring, they can be used as an active recorder by connecting your headphones. You can also use the built-in GPS to log your track using the Transect Mode function.
No, the Chorus cannot be powered externally.
The Ranger can utilise external power and solar panels.
The Chorus is only compatible with the low-profile ultrasonic and acoustic microphones.
If you need to use a directional microphone, you will need to use a Ranger.
Theoretically yes, however the performance may be compromised. Microphones lose sensitivity over time, so you should get your microphones serviced to check their functionality. Additionally, old versions of the microphone (whilst they may work) will use more power than our current microphones, so the battery life will be compromised.
The division ratio is set at 8. The division ratio affects the amount of data which is saved in Zero Crossing recordings, the lower the division ratio, the greater the number of data points in the resulting sonogram. The division ratio for the FD audio output is 16.
Sample rate refers to the number of ‘samples per second’ taken during recording, measured in kilo samples per second (ksps). The sample rate of the Anabat Scout is 320ksps.
To improve the GPS lock, move to an area with a clearer view of the sky for better satellite reception. You can still record without a GPS lock, but the timestamp and location data may not be accurate. Initially, your GPS data may be less accurate, but this will improve within a few minutes as more satellites are locked.
The bat counter creates a .csv spreadsheet from presses of the In and Out buttons on the detector. Each In or Out record is time and date stamped, and it records a total tally of ins and outs and the GPS location at each button press. This feature is designed to help you with roost emergence counts.
The gain setting of the Walkabout is fixed and is not user adjustable. The gain of amplifier is configured to suit the full dynamic range of the microphone so no adjustment is required. Faint calls can be made brighter on the display by adjusting the spectrogram brightness and contrast settings.
If you want to keep your selected settings from being accidentally changed, we recommend you save them in a profile where the important settings are locked. That way, your helpers can still collect data, without altering your settings accidentally.
If you are using a full spectrum display you may need to adjust the spectrogram brightness/contrast settings. Very faint calls will need high brightness & contrast settings. If you are using zero crossing display, you may need to increase the zero crossing sensitivity. This should be increased right up to the point where you start to get the occasional dot drawn on the graph by background noise. Full Spectrum display and recording is recommended when looking for faint/whispering bats or maximum sensitivity is required.
Alternatively, your detector may have frozen. This is most commonly caused by an unsuitable, old, or partially full SD card. Ensure your memory card is meeting the minimum SD card requirements and empty/formatted before each recording session.
If there is a large amount of low frequency noise present you can adjust the trigger frequency range to exclude signals below a certain frequency. For example, if there are a lot of insects below 10 kHz, you can set the minimum trigger frequency to 10 kHz and the auto record or compressed view will then ignore any signals outside that range. You can also try using the clip on directional cone attachment.
When you receive your detector you need to charge the batteries fully, with the detector turned on before first use, this will calibrate the battery gauge. You can repeat this process again at any time to re-calibrate the battery gauge. If you have done this, try using some of the power saving options outlined in the user manual. If you believe your detector has a faulty battery, please contact your local distributor. Typically the detector will run for approximately 6 to 8 hours, depending on how the detector is used and the amount of files being saved. In Screen Off mode the detector will record for approximately 12 hours.
Anabat Insight does not identify bat calls to species. It does have a plug-in for BatClassify UK, which will perform automated identification of UK woodland bats. Outside of this region, automated identification is not currently provided.
Anabat Insight does have filters, search and decision tree tools that you can use to build your own automated identification system. If you are not confident with species identification in your region, you can still use Anabat Insight to separate noise files, so that you can reduce the volume of files being sent to an expert for analysis. This will likely save you money on your analysis costs as it will save the expert time.
The functionality and features of the free and paid versions is exactly the same, the only difference is the type of files that can be opened/analysed. The free version will only open files from Titley Scientific’s current detector range: Ranger, Chorus, Walkabout, Scout, Swift, Express FS and Express. In the case of the Express, a firmware update (released several years ago) is required to sign the files as they are being recorded.
The paid version will open any file from any detector, including competitor brands and historical datasets from older Anabat devices.
Check if Insight has access to the internet by selecting Help, then Check for Update. If the window appears with an error message, Insight is being blocked from the internet or you are not connected to the internet. Ensure your internet connection is working, if it is, then try disabling any antivirus software or firewalls. Once they are disabled, see if the maps load. You may need to create exceptions for Anabat Insight in your antivirus software.
Before you can add an action, you need to ensure the search criteria is clicked/selected in the search bar. Once selected, the Add button will be available.
Sometimes a floating panel may disappear off the screen if using multiple monitors, or may be accidentally closed. To bring back a panel, click on Windows, then Dockable Windows, then Restore Windows.
SWIFT, EXPRESS & EXPRESS FS
While these recorders are designed for passive monitoring, they can be used as an active recorder by connecting your headphones. You can also use the built-in GPS to log your track using the Transect Mode function.
Yes, using an appropriate solar panel, battery, and regulator system. Contact your Titley Scientific distributor for more information.
When recording in full spectrum, if you find that your spectrogram has excessive echoes (“messy”), it is likely due to echoes from where the microphone was mounted. We recommend that you use the supplied extension cable to mount the microphone away from the detector itself, or any other flat surfaces (such as boxes or walls). This will produce much clearer recordings.
The Anabat Express only records in zero crossing (.zca). If you require full spectrum, you may like to consider a full spectrum upgrade for your Express, which can be performed by our distributors.
Your detector will look the same, with a similar user interface on the inside. There will be an extra button that allows you to swap between full spectrum (FS) and zero crossing (ZC) recording, as well as adjust the sensitivity between 3 levels. More detailed settings can be adjusted by connecting the Express FS to the computer via USB, just as it is now.
ZC files will be recorded in .zc format (individual sequence files), not .zca (an entire night) like it previously did.
The new SD card size limit will be 512GB (not 32GB as it currently is).
All other existing features of the Express will remain.
If your detector secured a GPS fix when first turned on, then cannot secure a subsequent fix the next day, it will default to the previous GPS location and remain in the selected recording mode (eg. Night Only). However, if you deploy your detector and it does not get an initial GPS fix, it will record in Continuous Recording mode (with the Check LED flashing). The detector requires a GPS fix whenever it is first turned on in order to record relative to sunset or sunrise times.
This may be an issue if you change the batteries, or restart the detector, inside a cave (for example). To avoid this issue, you can create a schedule with Toolbox that will run from sunset to sunrise (or your preferred times), and then manually specify the latitude and longitude, there is a map to make this easier. Set the end date to after you expect the batteries will run out. Save the schedule on the SD card and then use the recorder in schedule mode.
Yes, the directional microphone is compatible with both the Express/FS and Swift.