Research update June 2019


Postdoctoral Fellow Tara Crewe from Charles Darwin University provided a full report including the items below.

Prescribed Burns 
In February 2019, prescribed burns were undertaken by project partners Balanggarra Rangers and WA Department of Biodiversity, Conservation and Attractions. These burns were implemented across areas to the west of Wyndham township as a preventative measure against large-scale and late-season fires. Because of the unusually low rainfall in the previous (2018-2019) wet season, these fires covered a larger area than expected.

Installation of More Receiving Towers
In 2018 we installed six automated radio-receiver towers to receive signals from the Gouldian finches fitted with minute transmitters. These proved very effective. In March 2019 the research team has now installed 17 additional ‘pop-up towers’ with collinear (omni-directional) antennas across the Wyndham area. These additional towers have an approximately 2 km detection range and should improve our ability to track tagged finches throughout the complex topography surrounding the town of Wyndham. This should lead to better resolution in estimates of habitat patch use.

Radio tagging more birds
In early May 2019, radio transmitter tags were attached to a further 54 finches. Radio tags are active for 12 hours each day from approx. 5am to 5pm, and will have a battery life of approx. 120 days. With the three proposed trapping sessions in 2019, a total of 180 finches will be tagged, providing movement and habitat use data for the dry season and into the wet.

Vegetation surveys – May 2019
An initial set of vegetation surveys was conducted across the study area with 49 sites surveyed for tree and grass diversity as well as fire history. At each site, several drone images were taken at a vertical height of 50m. On these images, the grass species Triodia pungens and Sorghum stipoideum were clearly identifiable. From the drone images and vegetation surveys, a model will be developed to demonstrate the estimated abundance and distribution of key grasses for our finches. This model will also be used in conjunction with the fire history of Wyndham to understand how fire history can influence the availability of grasses and therefore finch movement.

Stable isotope analysis
During vegetation surveys, seed samples were collected for several grass species including Sorghum stiopodeum, S. plumosum, Eriachne obtusa, and Aristida latifolia. Blood samples from birds were also collected where possible. These blood and seed samples will be sent to a lab for stable isotope analysis. By comparing the isotope ratios among blood and seed samples in the early, mid and late dry seasons, we will test the potential to use this method to understand how diets vary among the three finch species, and how early they begin to introduce perennials into their diet to compensate for declining sorghum availability.

Remote sensing Cameras
We are also using remote sensing cameras in conjunction with ‘mini towers’ to determine individual movements around waterholes. The limited-range antennas will help provide data such as the time of day the birds return to a waterhole, and how long they stay for. Cameras will also be deployed at these waterholes for the duration of the fieldwork (with a minimum of 7 days). During the Waterhole count in September this year our Save the Gouldian Fund volunteers will also be using these cameras at waterholes where counts are done.

So we are making great progress on many fronts. Save the Gouldian Fund has contributed significant cash into this project and we can only do that from donations. If you wish to support our ongoing work go to the Donations page.