Kath Shurcliff | Grasswren project Coordinator
Results of our 2024 Grasswren Surveys
Have a close look at this burnt-out patch (photo 1) of what used to be spinifex hummocks. Would you even bother to search for Carpentarian or Kalkadoon Grasswrens here? Even if you knew they had been there this time last year (May 2023)? But that was before the wildfires that swept through the area late last year (2023). Would you bother?
Well, that was the scenario we were presented with at this year’s BirdLife Northern Queensland (BLNQ) Grasswren surveys, northwest of Mount Isa in outback Queensland. Wildfires in late October–November 2023 had burnt out much of the spinifex-laden sandstone ridges and outcrops there.
It is also an area with high concentrations of both Carpentarian and Kalkadoon Grasswrens. We were concerned about what our surveys this year might yield – would the Grasswrens still be there, and in what numbers? Would there still be sufficient patches of unburnt spinifex to provide needed refuges, nesting locations, food sources?
What did we find? As pictured in Photo 1 above, there was much burnt-out country, often with only small hummocks of spinifex escaping the fires, burnt-out canopies of the trees, and now-dead Acacia shrubs. But there were also areas with larger patches of unburnt spinifex, and rocky outcrops (photo 2).
The burning program undertaken by Southern Gulf NRM over the last few years appeared to have paid off, as there were numerous sites where the wildfire met with previous fire-scars. These locations had larger patches of unburnt spinifex, like that shown below (photo 3) with a fire-scar from 2021.
Our results were surprising – yet pleasantly so! Not only did we find Grasswrens in these sites, but when we compared results from 2023 with the same sites in 2024, we could not find any differences between these two years over all the measures we use to assess changes. Have a look at Graph 1 below for Carpentarian Grasswrens.
This graph for Carpentarian Grasswrens shows the percentage of sites with Grasswrens; percentage of sites with Carpentarians (Carp); percentage of those sites which had more than one group of Grasswrens; percentage of groups with more than two birds (an indicator of breeding success); and the number of survey points needed to find a Grasswren group. All these measures are very similar between the two years, indicating the wildfires did not have a measurable impact on the Carpentarian Grasswrens. A similar picture emerged for Kalkadoon Grasswrens.
Although these results are heartening and a relief, they only indicate that the Grasswrens were able to find refuge during the period of the wildfires, and have been able to survive over the wet season. There was extensive evidence on the ground of regrowth of the spinifex from the burnt-out hummock root stocks, seedlings germinating, and regrowth of leaves on the tree canopies (as can be seen in photo 4). And with that regrowth, there was abundant insect life and seeds, providing adequate food.
But what will happen as the dry season sets in and that flush of regrowth and resources disappears? Will the numerous groups all be able to survive? Will they be able to successfully breed?....or will the extensive wildfires start to take a real toll on these Grasswrens? We are already planning our revisit to these sites in 2025. Will you be willing to join us and help discover the answers to those very questions?
As always, none of these results would be available if it were not for the expertise, time and resources that our team of dedicated volunteers contribute. This year we owe our thanks to Carolyn Scott, John Mulham, Mark Horvath, Kath Shurcliff, Mike Grigg, Ceinwen Edwards, Henry Stoetzel, John Lowry, Mike Johnston, Dave Houghton (pictured below), with Joe Power, Karin Rencken and Jules Kramer (missing from photo). We are also indebted to Southern Gulf NRM who secure the funds for us so that we can undertake these surveys.
A very big Thank You!
