This blog post is provided by Alex Maisey and tells the #StoryBehindThePaper for the paper “Foraging activity by an ecosystem engineer, the superb lyrebird, ‘farms’ its invertebrate prey”, which was recently published in the Journal of Animal Ecology.

The Superb Lyrebird is renowned worldwide for its remarkable mimicry and captivating courtship displays. However, beyond its extraordinary songs and dances, this iconic species plays a pivotal role in shaping its forest environment. Increasingly, lyrebirds are recognized as key ‘ecosystem engineers’—species that modify their environment in ways that create, maintain, or destroy habitats, reshaping the structure of the ecosystem.

Our earlier research has found that lyrebirds shift an astounding amount of soil during foraging—around 155 tonnes per hectare per year—more than any other species recorded. As they forage, lyrebirds mix mineral soil with leaf litter, bury fine twigs and branches, and accelerate decomposition. This process creates a nutrient-rich topsoil, which not only supports a wide range of forest life but also plays a significant role in moderating fire behavior under most bushfire conditions.

We hypothesized that such extensive soil and litter modification would impact the macroinvertebrates living in the topsoil—important decomposers and a key food source for lyrebirds. To explore this, we conducted a two-year manipulative experiment in the eucalypt forests of south-eastern Australia.

Manipulative experiments, which involve intentionally altering certain factors in an ecosystem to observe the effects, are challenging to conduct in natural settings. However, when done successfully, they provide valuable insights into complex ecological questions. We set up our experiment at 18 study sites across the forests, manipulating lyrebird access to small plots. At each site, we established three plots: one where lyrebirds were excluded (control), one where we simulated lyrebird foraging using a hand rake (raking), and one where lyrebirds could forage naturally (lyrebird treatment). This setup allowed us to compare the effects of ecosystem engineering and predation on macroinvertebrate communities.

During the spring growing season, we collected leaf litter and soil from each plot and extracted the macroinvertebrates, which were classified and measured for biomass. We collected samples at the beginning of the experiment and twice over the two-year study.

Our findings were exciting. Taxonomic richness significantly increased in the ‘raked’ plots compared to the ‘control’ plots, proving that lyrebird foraging enhances habitat for a wider range of species. We believe this is due to the unique microhabitats created by lyrebirds. Their foraging exposes mineral soil, mixes it with leaf litter, and buries twigs, creating dynamic and varied environments that support different macroinvertebrates.

We also observed that macroinvertebrate biomass in the ‘raked’ plots increased over time, compared with both the ‘lyrebird’ and ‘control’ treatments. This suggests that while lyrebird foraging provides the ideal conditions for macroinvertebrates to thrive, the absence of predation allows populations to grow even further.

This farming mutualism is playing out across millions of hectares of the eucalypt forests of eastern Australia. Lyrebirds turn over the entire forest floor every ~20 months, maintaining dynamic microhabitats, shaping plant germination patterns, and even altering fire behavior under mild conditions. Without the lyrebird, these forests would be vastly different—poorer in biodiversity and less resilient to disturbances like fire. Understanding and protecting these natural ecosystem engineers is crucial for maintaining the health of our forests for future generations.

Read the Paper

Read the full paper here

Listen to the Podcast

Listen to Alex’s podcast, where he talks about the research in more detail, here