Wildlife Acoustics Blog

song meter

How should I save, in .wac or in .wav?

How should I save, in .wac or in .wav?

If you have used our ultrasonic Song Meters before, you may be familiar with two different options for saving our recordings, triggered .wav, and our proprietary compressed format, .wac. While we recommend triggered .wav format in almost all cases, there are a few instances where it may benefit you to use .wac format instead.

  • First, we recommend our ultrasonic users record to triggered .wav format for several reasons:
    Triggered .wav format comes with noise scrubbing capability, which allows for more accurate triggers. This means you won’t be wasting card space with recordings that have been falsely triggered by non-animal noises, such as rain. Though .wac files takes up less space than .wav, this could actually offset the amount of space that would have been saved recording in a compressed format if you are in an area prone to ultrasonic noise.
  • Wav is 30% more energy efficient than .wac and can be used directly for ZC analysis
  • If you are using a Song Meter SM3, you will have automatically embedded metadata in your .wav files.

So when is it preferable to use .wac?

If you are interested in GPS tracking, you may find it more valuable to record to the .wac format. .Wac recordings take GPS information every second, allowing for continuous tracking data. While some GPS data is available with .wav, you will have fewer data points than in .wac.

Another advantage of .wac is independent triggering. If you are recording different species on different channels, you may want only one channel to trigger at once. For example, you may want to record birds on one channel, and bats on another. You wouldn’t want bats to trigger recording on both channels if there won’t be another birds to record for several hours. In situations such as these, the .wac format will be much more space saving than .wav.

Listening for Signs of Life: A case study on using acoustic monitoring to assess remote seabird populations

Biologist Luke Halpin

Biologist Luke Halpin:

“My research takes place in Gwaii Haanas National Park Reserve, National Marine Conservation Area Reserve and Haida. Heritage Site in Haida Gwaii, an island archipelago off the west coast of British Columbia, 80km west of Prince Rupert. Haida Gwaii is home to 1.5 million breeding seabirds, including 50% of the global Ancient Murrelet population and large nesting populations of several other seabird species. Haida Gwaii is the only breeding location for Ancient Murrelets in Canada.

On Haida Gwaii, invasive rats are a major threat to the conservation of these seabird populations. In 2010, Gwaii Haanas National Park Reserve and Haida Heritage Site began a large rat-eradication project called Night Birds Returning (SGin Xaana Sdiihltl’lxa, in the Haida Language) on a number of islands. As a component of this project, I used Song Meters to explore presence and relative abundance of four seabird species on rat-infested and rat-free islands. The species I examined, in collaboration with Dr Carita Bergman, Terrestrial Ecologist in the Parks Canada Agency, includes Ancient Murrelets Synthliboramphus antiquus, Cassin’s Auklets Ptychoramphus aleuticus, Fork-tailed Storm-Petrels Oceanodroma furcata and Leach’s Storm-Petrels Oceanodroma leucorhoa."

Research Process

“I used the Song Meter acoustic data to assess the effect of rat presence on relative abundance of these nocturnal seabirds. I examined relative abundance and the seasonal colony attendance period from presence and absence data derived from the Song Meter acoustic recordings.

Meet Song Scope, Our 3-in-1 Spectrogram Analysis Tool - Part 3: Creating a massive Song Scape with Song Scope

Meet Song Scope, Our 3-in-1 Spectrogram Analysis Tool - Part 3: Creating a massive Song Scape with Song Scope

Song Scope is our spectrogram tool, designed to review recordings made by Song Meter SM2+, SM2+ Aquatic, SM2M+ Deep Water, Submersible or other conventional bioacoustics recording equipment.

Song Scope is fast, intuitive, and very flexible. It’s really three tools in one. That’s why we’ve created a three-part blog series to show you what Song Scope can do!

In Parts 1 and 2 we told you that Song Scope is a easy to use Spectrogram Viewer and sophisticated Recognizer builder.

Wildlife Acoustics is proud to support wildlife conservation efforts

Merlin Tuttle's Bat Conservation Bat Conservation International Bat Conservation Trust Wildlife Habitat Counsil