NHBS: In The Field – Song Meter Mini Bat Detector

The SM Mini Bat is the latest addition to the ultrasonic range of acoustic recorders produced by Wildlife Acoustics. This passive bat detector offers comparable versatility and quality to the highly successful SM4 Bat but at a much lower cost and a smaller size of only 12cm x 13cm. These impressive detectors also feature an easy to use configuration mode through your smartphone or tablet over Bluetooth.

In mid-March we deployed an SM Mini in a rural location in South Devon to record any emerging bats, as the spring season got underway. Our aim was to find out how easy setup is when using the Mini Configurator app and to get an example of its recording quality. Originally our plan was to retrieve the detector after a period of three weeks, however the developments around Covid-19 meant that it was unsafe to do so. Therefore in this blog we will cover our experiences with setting up and deploying an SM Mini. Once social distancing rules are lifted we will provide a follow on update with our recordings.

We used a 32 GB SDHC card, however the SM Mini Bat can support SDXC cards of up to 1TB. The SM Mini Bat comes with a built-in microphone and when powered using 4x lithium-ion AA batteries it will record for up to 30 ten-hour nights. You can add an additional acoustic microphone to record birds, amphibians and other species when not using the ultrasonic microphone.

Setting Up

The SM Mini is designed to be used with a companion app called Mini Configurator. This free app allows you to easily configure the SM Mini’s recording settings before deployment as well as check the status of your detector while it’s in the field.

When powered on the SM Mini Bat emits a constant Bluetooth beacon, and when you are within range of this beacon the Configurator app will automatically detect the recorder and display it in the recorders screen of the app. You can now press the status icon on the app and view the current status of the detector, including SD card capacity, battery life, recording mode and number of recordings taken.

To set up or edit an SM Mini’s recording schedule you must pair the detector with the app. The first step in this process is to hold down the PAIR button on the SM Mini for three seconds, which prepares the device to be paired (indicated by the green flashing Bluetooth light). On the Mini Configurator app a ‘pair’ icon will then appear next to the detector’s name, and once pressed the app will be paired with this detector. Once paired the SM Mini synchronises its time and date to your location and a new ‘configure’ icon will appear next to the detector, which grants access to the SM Mini’s recording settings. These settings include the recording schedule (e.g. an hour before sunset through to sunrise), recording format (zero crossing or full spectrum), minimum trigger frequency and recording length.

What we found

Setting up an SM Mini and getting to grips with the Configurator app can seem daunting at first, but with the quick starter guide and Wildlife Acoustics’ helpful online tutorial videos, we found it to be a relatively straight forward process. The app has a simple user interface with clear graphics and together this really helps make navigating the app easy. This was a welcome change when compared to the issues that new users can have when navigating the older style LCD menus on previous detectors.

The beacon status system has also proved incredibly useful whilst we have had the detector deployed. Since the social distancing restrictions came into place, we have been unable to access the detector. However we were able to guide the owners of the land where the detector is deployed, through the process of installing the app and checking its status for us. This has been incredibly helpful as we can see whether we have recorded any bats in its current location, as well as whether the batteries need to be replaced.

Despite its small size we were still able to run a python lock around the detector, however as our location was a private residential area we were not concerned about theft and so opted for using a few cable ties to secure the detector in place.

Our Opinion….so far

The SM Mini Bat offers a user-friendly passive bat detector building on previous iterations in the Song Meter bat detector range. Its small size means it’s much easier to store and transport, and it is much more discreet when deployed in the field, compared with other detectors. Being unable to add an additional external microphone is a limitation to keep in mind, however for us this wasn’t an issue.

 We will post a follow up blog once we are able to retrieve our detector and access our recordings.


The Song Meter Mini Bat Detector is available to order from the NHBS website. For assistance with any queries regarding our range of bat detectors, please do not hesitate to contact our team of Wildlife Equipment Specialists on 01803 865913 or equipment@nhbs.com.

Introducing the new SM4BAT from Wildlife Acoustics

The new SM4BAT range of passive bat detectors from Wildlife Acoustics was announced at the 2015 Bat Conservation Trust AGM.
Song Meter SM4BAT

The Full Spectrum (FS) version will allow you to record bat calls in 16-bit resolution at a sample rate of up to 500kHz on a single channel. The Zero Crossing (ZC) version is also single channel and will record zero crossing files. Both are weatherproof, come with a three year warranty and will record for up to 30 (10 hour) nights when powered with four high quality d-cell batteries.

The SM4BAT FS and SM4BAT ZC are now available to order.

 

Update for Wildlife Acoustics users: SMX-U1 and SMM-U1 Microphone Weather Protection

We have received the following message from Wildlife Acoustics which contains essential information for users of the SMX-U1, SMM-U1, and SMX-Horn microphones.


Due to a small number of microphone failures occurring from wind driven rain in our continued testing, we have decided to include protective windscreens with all future microphone shipments. We have also decided to provide windscreens to all existing SMX-U1 and SMM-U1 microphone customers at no charge. Additionally, we will be providing a larger windscreen for the SMX-Horn directional attachment, and again providing these at no charge to existing customers.

Though we did not experience microphone failures in our initial rigorous weather testing of the microphones, some recent failures observed in the field indicate that the microphone element may still be at risk of damage in the event of extreme weather. The main concern is specifically high-velocity wind-blown rain resulting in water spray entering the FG sensor causing damage to the membrane and/or electronics inside. The risk is greater when deployed with the ultrasonic horn attachment. Though we have seen issues with only a handful of microphones, we recommend that you use windscreens for long-term deployments in all areas susceptible to heavy wind driven rain out of an abundance of caution. We view the use of windscreens as a preventative measure to avoid any chance of damage to the microphone element when used in severe weather. For short-term deployments with predictions of less severe weather and in dry climates, you can avoid using windscreens.

The windscreens will attenuate ultrasound by only a few dB when dry. However, they will block most ultrasound when soaked with water, until they dry. Drying time can vary significantly based on temperature, humidity and wind. Given this information, we leave it to you to decide the best course of action for each deployment.

wa-windscreen-1

Secure the windscreens for the SMX-U1 and SMM-U1 microphones with the included C-clip. Make sure there is an air gap between the windscreen and the microphone as shown below. (Do not pull the windscreen down tightly).

For the SMX-Horn directional attachment, secure the large windscreen with the included zip-tie as shown below. Exact positioning is not important.

wa-windscreen-2

If you have purchased one or more SMM-U1, SMX-U1 microphones or the SMX-Horn attachment from NHBS you do not need to do anything, we will send your microphone covers to you free of charge in the next few days.

Please contact Wildlife Acoustics at support2015@wildlifeacoustics.com if you have any further questions or concerns.

Firmware updates from Wildlife Acoustics

New Firmware available for SM2, SM3 and SMZC product families

These firmware updates all address an SD card compatibility issue we have recently seen in a number of specific SD card models. If you have experienced SD card errors or corruption, this firmware update may resolve these issues.

SM3/SM3BAT/SM3M Firmware 1.2.7

In addition to the SD card issue above, this version also improves the interpretation of a program containing non-infinite loops. The firmware can be found here.

SMZC Firmware 1.0.6

In addition to the SD card issue above, this version also improves the interpretation of a program containing non-infinite loops. The firmware can be found here.

SM2/SM2BAT/SM2M Firmware 3.3.9

The firmware can be found here.

You can contact support2015@wildlifeacoustics.com if you have any questions.