Old friends and new places - Our Grasswrens in May 2025

Kath Shurcliff | Grasswren Project Leader

In late October–November 2023, extensive wildfires swept through the core areas for Carpentarian Grasswrens, north-west of Mount Isa in outback Queensland. BirdLife Northern Queensland has been monitoring both Carpentarian and Kalkadoon Grasswrens in that area for several years now, so we have a good baseline of just where we can find groups of both species.

Last year (May 2024) we focused on surveying the burnt-out spinifex ranges. Surprisingly, we found that at most of our known locations for Carpentarian Grasswrens, as well as Kalkadoons, both species had survived the fires. We put this down to the numerous patches of unburnt spinifex and rocky crevices among the ranges, which had provided refuges for the grasswrens during and after the 2023 fires. An example of such a refuge alongside the fire-scar is seen in Photo 1 below.

Photo 1. Fire-scar in May 2024 with rock refuges and unburnt batches of spinifex. Photo by C Scott.

We wondered how the birds would fare during the subsequent dry season. What would we find when we resurveyed those same sites in 2025? Had they been able to thrive and breed, with limited spinifex, shrub and tree cover?

During our survey in May 2024 we had found that the spinifex was mostly regrowing directly from the surviving root stock. However, 12 months later (May 2025) spinifex seedlings were also found extensively throughout the area, indicating longer term recovery was under way. The trees had mostly replaced their canopies, so there was once again good shade cover.

Birds we found in 2024 were also found in 2025 – like finding old friends again, back in the same locations. These grasswrens show remarkable fidelity to their sites, and we often find them year and year again within 200 m of our first encounter with them. This is true, even if their ‘home’ has been devastated by fire, as seen in Photo 2 below taken in May 2024, six months after the 2023 wildfires, and then again in 2025, 18 months later (see Photo 3 below).

Photo 2. There was some recovery of spinifex, shrubs and small trees in 2024, six months after the 2023 wildfires. Photo by D. Houghton.

Photo 3. Evidence of spinifex, shrubs and small tree recovery in 2025.

Although we did find most of our birds still resident where we had found them previously, there was one major change this year. Over the previous three years, about 15% of our encounters with Carpentarian Grasswrens were of groups with more than two birds. When birds breed during the previous late dry/wet season, the immature birds stay with the parents and we find them together, often crammed at the top of a termite mound, looking us over (as evident in Photo 4 below).

Photo 4. A Carpentarian Grasswren family group greets us on their ‘home’. Photo by D. Houghton.

However, this year that percentage of groups with 2+ birds dropped down to less than 5%! (See Figure 1 below). Almost all our encounters were with just pairs or even single birds – there were no young birds with them! This may suggest limited successful breeding during the previous wet season.

Figure 1. Percentage of Carpentarian groups with more than two birds from 2022 to 2025, showing a sudden drop in May 2025.

However several of us felt that the birds might have been actively breeding while we were doing the surveys in May this year (2025) – birds may have been cryptic as we often encountered just single birds. Were their mates sitting on nests or hidden away with youngsters? If so, we would anticipate that next year (2026) we will find our usual percentage of groups with 2+ birds.

This year we also visited areas on the northern boundaries of Calton Hills, one of our main survey properties. We found Carpentarians in new locations, helping to fill in gaps in their known distribution. They were even found in recent fire-scars from early 2025, again showing their ability to find refuge areas after devastating fires (see Photo 5 below).

Photo 5. Burnt out spinifex and trees from fire in February 2025.

Another discovery during this year’s survey was a location close to Mount Isa, which has the highest density of Kalkadoon Grasswrens that we have been able to find so far. We recorded a record 13 Kalkadoon groups over 53 survey points, being one group of birds in about every four survey points. Our usual measure ranges from one group for every 14 survey points to as high as 36 points. This location includes quartzite outcrops which we have previously found to harbour Kalkadoon Grasswrens at regular intervals.

Thanks to the partnership and support of Southern Gulf NRM we have been able to maintain our mid-long term monitoring of grasswrens, which spans years before and after widespread wildfires in the region. This has enabled us to track the species’ ability to survive and the extent of their recovery from the impacts of these fires.

Our thanks to our volunteers who each year provide the much-needed skills, expertise, time and resources to make these surveys successful. This year the work was completed by (left to right in Photo 6): Steve Francis, Ceinwen Edwards, David Secomb, Mike Johnston, Kath Shurcliff, Nigel Secomb, Kerry Watson, Jeff Watson, Carolyn Scott, Bronwyn Horvath, Mark Horvath, David Houghton, and, missing from photo, David Jopson, Kerrie Turner, and Jules Kramer.

Photo 6. Our volunteers for 2025. Photo by N. Secomb.

We were also ably assisted by several rangers from the Kakatungu, Indjalandji-Dhidhanu and Lake Eyre Basin Ranger groups, who are undertaking long-term monitoring and management actions On Country. We thank them for their ongoing support and assistance in the grasswren surveys.