Change of meeting venue for COG/Canberra Birds
Until further notice the venue for our 2026 monthly members’ meetings will remain the Bugang Room at the Denman Village Community Centre, located at 5 Felstead Vista, adjacent to the Denman Prospect shops (see Google Maps link https://maps.app.goo.gl/NqW3XrN5iJf8dzRe9)
This is a light, spacious, modern event venue with a kitchen. There is plentiful parking, under lights, close to the door and with several disabled parking spots outside the door. The room is on the first floor, accessed by two flights of stairs or by a lift.
To help guide you once there the Canberra Birds Sandwich Boards will be outside the front door.
For people attending the meeting by public transport, the R10 bus provides a very good service around every 15 minutes from the ANU through Civic to the Denman Prospect shops with the bus stop opposite the venue. For example, a bus runs to there from 6:57 to 7:23 pm and return buses at 9:05 or 9:35 pm arriving at the ANU at 9:31 and 10:01 pm, respectively.
At the August meeting there will be three presentations, the first a shorter one than usual, then followed by 2 longer presentations on aspects of bioacoustics recording.
The first will be byGang-gang editor Zac Flegg providing a “Canberra Bird Blitz Summary”
The Canberra Birds Blitz is a long-running annual survey project that began in 2005 and aims to cover the entire range of the ACT; providing a snapshot of the species that call the region home. In recent years, the project has been left without a coordinator, leading to what has now been termed the “Bird Blitz, lite”. This quick presentation aims to provide an overview of the species detected during the last few years of the survey, changes in methodology and provide a call for coordinators.
The next speaker will be Dr Jurian Hoogewerff of Hoog Consulting on “Introduction to technical aspects of ecoacoustic recording.”
Ecoacoustics encompasses a wide range of sound domains; geophony, biophony and anthrophony. Bioacoustics focusses on how animals make use of sound and how they respond to all sounds. Most animals have a similar frequency hearing range as humans about 20 Hz to 20 kHz or slightly higher but produce sound in a constrained range.
Recording sound pressure waves requires a sensitive variable pressure sensor, a microphone, to translate the small air movement into a variable electric current. The weak low voltage signal from the microphone needs to be amplified.
The amplified signal is nowadays converted to a digital signal, using an analog to digital converter, an “ADC”. The ADC sampling rate needs to be at least twice the highest required sound frequency (so-called Nyquist frequency) to obtain a useable digital representation. Another key parameter in the digitisation is the resolution in which the amplitude of the sound wave is sampled, called the bit depth. A 16-bit bit depth gives 216 = 65,536 steps resolution and is the typical CD quality. The digital data stream is subsequently captured by writing to a file on a disk or memory stick.
The first complete-package all-weather battery-operated time-lapse sound recorders (microphone + amplifier + ADC + sd card writer + CPU) that were easy to operate were the “Songmeters” made by Wildlife Acoustics in the USA in 2007 at a A$1500 price point. Since then, competitors, like Frontier Labs from Brisbane in 2011 have come on the market and driven significant quality improvements. In 2017 the open source Audiomoth recorder set a new standard for cheap miniature recorders (A$100) and other manufacturers are copying and improving the design and capabilities. In the presentation more technical details and software to inspect the large amount of data produced when recording in time-lapse mode for weeks will be explained.
This will be followed by Zac Flegg on “Nightjars in the Cotter—Methods, Findings and Ethical Implications”
This presentation overviews a recent research project run over the summer of 2025-2026. Using Passive Acoustic Monitoring (PAM), the White-throated Nightjar and other nocturnal species were recorded. This project was a direct response to recent records within the COG Area of Interest (AoI), combined with a lack of quality data surrounding local Nightjar stay and calling patterns. The project successfully recorded a total of 112 distinct species. This included regionally interesting species such as Powerful Owl, Red-capped Robin and Brush Bronzewing. This underlines the potential application of audio recording as an environmental monitoring tool.
One key finding of the project was high levels of playback use around the Cotter during the study period – often for hours at a time and for almost a quarter of the study period. At a time when Nightjars are known to breed, the potential impact of this action cannot be overstated. This presentation will conclude by outlining the outcomes of the project. This includes the development of a custom AI model training for Nightjar call recognition.