What is bioacoustics?
Bioacoustics is a cross-disciplinary science that combines biology and acoustics; broadly speaking, it is the study of sounds produced by or affecting living creatures. The field of bioacoustics includes within its scope: anatomy and physiology of sound production, auditory mechanisms and capabilities, animal communication and associated behaviors, species identification and population assessment, and the influence of human-made noise on animals. In the context of a Breeding Bird Atlas, bioacoustics is a tool that will facilitate a new way for participants to be involved and contribute to the atlas.
When recordings are made using specific recording equipment and easily-followed sampling protocols, the resulting recordings can be processed to produce data on species presence and abundance. In essence, a bird survey is generated by identifying acoustic cues and bird songs on the recording. Recent development of weatherproof, commercial autonomous recording units (ARUs) has triggered broader interest in using passive acoustic monitoring as a means to detect rare or elusive species, or to get better representation of entire avian communities.
Bioacoustics and bird monitoring
Bird monitoring involves the collection of information that permits an assessment on the population status or use of an area by species of birds. This is most frequently accomplished by people reporting observations of birds that are linked to a place during a specific time of year (e.g. summer, migration). Breeding Bird Atlas projects are major contributors to bird monitoring because atlases gather georeferenced information about birds using a systematic approach.
For millennia, humans have used animal sounds to recognize and find them. One of the key ways that we collect information about birds is through the use of sound. So, bioacoustics is somewhat inherent to the pursuit of birds because bird calls and songs are often the first, and sometimes the only, indication of a species’ whereabouts. This is why the ability to identify birds by auditory cues is an imperative skill for observers who conduct point-count surveys. During a bird point-count survey, it is not uncommon to have the majority of detections of individual birds arise from auditory cues!
It suffices to say that bioacoustics is a very important part of bird monitoring: Stick with it long enough, at some point in their career a citizen-scientist will encounter a survey protocol that requires skills to identify birds by sound. The point-count survey is a good example of this within the context of a Breeding Bird Atlas. While the ability to ‘bird by ear’ takes patience and a lot of practice to build proficiency, a basic understanding of vocalizations is something that can be learned in short order, and it can really expand your knowledge and awareness of the bird life in your area.
In the meantime, if you don’t already have the skills to bird by ear, recent advances in bioacoustics, and how to use recordings to produce bird point-count surveys, have opened new opportunities for the non-expert! Please consider making recordings and submitting these as point count data.
The following is an example of a bioacoustic recording made at 4:00am at a wetland near Foam Lake, Saskatchewan. During the first minute of the recording 10 species can be heard. For best results use headphones.
Bioacoustics and the Saskatchewan Breeding Bird Atlas
There are two ways that participants can make bioacoustic contributions to the Saskatchewan Breeding Bird Atlas, both involve using digital recording equipment and transferring the recording files to the Atlas Office. One way to make recording samples for the atlas is to use a handheld Zoom H1 or H2 Handy Recorder. This involves the atlasser visiting point-count survey stations to make a 5-minute recording during specified hours of day and in good weather conditions. Zoom recorders can be found at music stores for ~$250; the Atlas Office hopes to acquire some Zoom recorders to loan to participants in 2018. The second way to make recording samples for the atlas is to deploy a Song Meter autonomous recording unit at a location for a period of several days, moving the recorder to new locations over a period of several weeks, and eventually retrieving the recorder once the point-count survey season is over (i.e., after 7 July). Because recordings will be used to produce point-count data, it is imperative that recordings are made during the point-count season and during the correct times of day. The Atlas Office has a limited number of Song Meters that we can loan to volunteers who wish to get involved in the bioacoustics effort; please contact the Atlas Office if interested in adopting an autonomous recorder.
Instructions for Zoom H1 or H2 Handy Recorders
The Zoom recorder is an affordable handheld recorder that makes very good quality recordings. The Zoom H1 or H2s are not programmable or weatherproof, so they require attendance to make recordings in real time. When Zoom recorders are used to make a 5-minute recording at a point-count station, these recordings can be processed by a technician and serve as point-count data. Use of a Zoom recorder to make Atlas point-count recordings is similar to conducting the in-person point count in that survey stations still need to be visited during appropriate times, dates, and weather conditions (see point count manual for details), but instead of conducting the point count the observer uses the Zoom recorder to make a 5-minute recording. Upon arriving at the point-count station, the directions are simple:
- Affix Zoom recorder to a tripod with the recorder at breast height, use a windscreen on the microphone to protect the recording from wind noise.
- Stand the tripod at the survey station and begin the recording; use 2ch surround recording mode, gain setting 10, recording format should be set at WAV44.1kHz/16bit (see Zoom Settings for instructions)
- At the beginning of the recording verbally state: the atlas square, point-count station number, date and time. When making the recording stand a few meters from the recorders so as to reduce noise on the recording caused by chaffing fabric, shuffling feet, or other noises apt to be made by the atlasser.
- While the Zoom is making the recording, document on a checklist any visual detections of birds that are not singing or calling during the duration of the point count; this includes all species but often these will be species of ducks and birds of prey which are often readily seen but call less frequently than songbirds.
- Stop the recording 10-15 seconds beyond 5 minutes; be sure to make note of the file name and the station number so that the recording file can be renamed using an atlas square and survey station format (e.g., 12UXB45-01). The Zoom interface will not allow this many characters, so the files will need to be renamed later using a computer.
- Submit recordings to the Atlas Office (firstname.lastname@example.org) using a cloud-based computer file transfer service such as WeTransfer or DropBox.
Note: If you are interested in listening to your recordings and viewing the spectrogram of the recording, download the free program Audacity. A spectrogram is a visual representation that shows the frequencies which make up sound and how they change over time, allowing you to “see” the bird calls on your recording. To set up Audacity for viewing spectrograms, follow the instructions in the Audacity Settings document.
Instructions for Song Meter Autonomous Recording Units
The Song Meter recorder is a programmable, weatherproof digital recorder that can be set to a desired recording schedule and left unattended. In professional vernacular these recorders are referred to as autonomous recording units, or more frequently just the acronym ‘ARU’. The cost of a Song Meter ARU varies depending on the model, amount of SD memory required, and the Canadian /US dollar exchange rate, but generally speaking they run ~$1000 per unit. We learned from pilot work that ARUs can produce point count information from any environment, but that there are situations where the utility of the ARU is more beneficial and these include (1) use in remote environments such as much of Regions 15 and 16, and (2) targeting wetland environments where several species of birds are nocturnal, crepuscular, or otherwise elusive to sampling. In Regions 1-14, we will use the ARUs to sample wetland habitats. For each atlas square in Regions 1-14, we have identified ten randomly-selected wetlands of which we would like for three of these to be targeted for placement of an ARU. If possible, the three targeted wetlands should be of different wetland types, ideally one each of a class II, class III and class IV wetland following the Stewart and Kantrud Classification System. If the atlas square does not include representation of a given wetland class, still sample at three wetlands within the square and represent as many of the classes between II-IV as is possible. If you are interested in adopting an ARU to deploy in atlas squares where you are collecting bird observations, please contact your Regional Coordinator or the Atlas Office.