Cameron Brown
Save Tootgarook Swamp, Inc., Victoria, Australia

Background

Tootgarook Swamp, the largest remaining shallow freshwater marsh on Victoria’s Mornington Peninsula, holds immense ecological value as the region's most intact tall marsh and sedge wetland system. Due to widespread habitat loss in the Western Port and Port Phillip Bay regions, species dependent on freshwater wetlands, such as the Australasian Bittern (Botaurus poiciloptilus), have experienced significant population declines. The swamp has supported documented sightings of this federally endangered bird since 1891, with recent breeding calls suggesting the species may be nesting within the 650-hectare wetland.

Project Objectives

This project aimed to:

• Determine the presence and activity of the Australasian Bittern during its breeding season.

• Trial and evaluate a mixed-method approach to ecological monitoring that reduces human disturbance.

• Broaden understanding of wetland biodiversity using complementary survey techniques.

Given the species' elusive nature and preference for dense, tall vegetation, traditional survey techniques are often insufficient. The project sought to improve detection rates by integrating passive remote sensing alongside manual fieldwork.

Methods

Between July and December 2016, the following monitoring tools were deployed in Tootgarook Swamp:

• A SM3 Song Meter (donated by BirdLife Australia) installed in the wetland's lowest elevation point to detect vocalizations.

• Seven wildlife cameras placed in areas where Bitterns had previously been observed or flushed.

• A drone (UAV) with a mounted camera to visually survey inaccessible or dense parts of the swamp.

These technologies were used in tandem with traditional manual surveys, allowing for data cross-verification and increased observational reach.

Results

• The Australasian Bittern was positively identified using all three methods: Song Meter, cameras, and UAV.

• Remote sensing also led to the detection of 20 additional species (17 birds, 2 frogs, 1 bat), 12 of which were only detected through the Song Meter.

• Unique behavioral footage was captured through the wildlife cameras and UAV, offering insights into natural, undisturbed activity patterns.

• Some species were only detected via a specific method (manual, acoustic, or camera), confirming the value of a multi-modal approach.

This reinforced the principle that wildlife detection is influenced by survey method, as some animals are more likely to avoid humans during traditional fieldwork.

Conclusions

This case study confirms that remote sensing is a highly effective, low-impact strategy for monitoring cryptic wetland fauna like the Australasian Bittern. The integration of acoustic monitoring, motion-sensing cameras, UAV technology, and manual observation provided a comprehensive view of the swamp’s avian community.

Key takeaways include:

• Passive surveillance reduces human-induced disturbance, increasing detection of shy or secretive species.

• Multi-method strategies outperform any single technique in terms of species detection and behavior documentation.

• Desktop surveys should guide, but not replace, in-field research preparation and execution.

The success of this project sets a precedent for similar ecological monitoring programs in complex wetland environments and supports the conservation prioritization of Tootgarook Swamp.

Next Steps

• Data collected from the Song Meter has been submitted to BirdLife Australia for further analysis.

• Additional long-term monitoring and community engagement are recommended to secure protection and recognition of Tootgarook Swamp as critical Bittern habitat.