Australian buckeye cultivates food in forest-scale agriculture

Australia’s lush Southeast forest is underway in an amazing agricultural business, but farmers don’t wear work clothes or drive tractors. Instead, they have grand tail feathers and are known for their extraordinary sound imitation rather than their agricultural capabilities.

Scientists at La Trobe University have found that the advanced buckeye, an iconic Australian ground-based bird, actively “cultivate” its invertebrate prey by creating specialized microhabitats, thereby promoting the diversity and biomass of the organisms it uses.

“Lyrebirds have built ideal homes for their prey, created conditions through more food resources, and effectively became obese before eating,” said Dr. Alex Maisey, principal investigator at La Trobe University.

The study, published on March 5 in the Journal of Animal Ecology, reveals a complex ecological relationship that operates on an unparalleled scale of any other non-human vertebrate. Through ongoing foraging activities, the buckeyes can move 155 tons of soil and leaf waste per hectare per year, a sprawling ecosystem engineering project that spreads millions of hectares throughout Australia’s wet eucalyptus forests.

To test their farming hypothesis, the researchers built an elegant experiment using three different treatments: the fence excluded the buckeye, the fenced area, the researchers simulated the buckeye through handmade buckeye, and the unaccused area where the buckeye could naturally forage.

The results are surprising. In plots where researchers mimicked the Sevenleaf birds through rakes, invertebrates’ biomass increased by about 52% in two years. Meanwhile, in the untouched control plot, invertebrate biomass increased by only 3% during the same period. The diversity of invertebrate species also increased significantly in the rake block compared to the control group.

This pattern creates what scientists call a “positive feedback loop” – birds’ foraging behavior enhances the food resources they rely on, which operates similarly to how human farmers grow crops.

Dr. Maisey noted that this type of animal farming is “rarely seen in nature”, which makes Lyrebird’s behavior particularly important. The team’s findings show that the birds not only disturb the forest ground while hunting, but also create beneficial conditions for their prey.

The birds’ farming techniques are surprisingly exquisite. When buckeyes rake through leaves and soil, they create a complex microhabitat: fresh exposed mineral soil, complex mounds of mixed waste and soil, and complete leaf litter. This different landscape provides biodiversity for different invertebrates.

In addition, foraging actions make the soil less compact, improve aeration and create more pore space for invertebrates. Birds also mix leaves in the soil, which increases the surface area available for decomposition and increases productivity of debris and microbial communities, thereby essentially fertilizing their invertebrate farms.

While experiments show that the buckeyes do consume some cultured invertebrates, their agricultural practices generate enough new biomass to offset their predation, creating a sustainable system. Amphipods – Small crustaceans identified as the favorite prey item by researchers, responding particularly strongly to bird soil engineering.

The scale of this agricultural action really sets it apart. Unlike other known animal farmers, such as fungal culture ants or termites operating in relatively small local colonies, birds affect approximately 17 million hectares of forest ecosystems in eastern Australia.

Buckeye trees are extensive and active in millions of hectares of forest. Their agricultural actions play an important role in maintaining forest biodiversity. ” Dr. Maisey explained.

These implications go far beyond the Hornets and their invertebrate prey. By increasing the abundance and diversity of invertebrates, the Seven-Layer Birds may benefit many other forest species, including ground birds, reptiles and small mammals that feed on invertebrates.

The study also reveals another unexpected ecological service: The Buckeyes “shape the entire ecosystem by burying leaves and branches to reduce the intensity of bushfires, thus burning fuel,” Dr. Maisey said.

This firefighting effect is particularly important in recent years in Australian forests that have destroyed huge areas of land. By reducing the load on surface fuel by reducing the soil’s constant twists, the seven-layer bird may help create more fireproof landscapes.

Interestingly, the study found that the composition of invertebrate communities was significantly affected by ephedra tract predation, but only by their engineering activities. This suggests that bird feeding is selective, perhaps targeting larger or more mobile invertebrates, more easily detected when disturbed.

This study represents an important step in understanding ecosystem engineering, in which organisms physically modify the environment in a way that creates, maintains, or destroys the habitat of other species. Although ecosystem engineers are documented in various situations, an example of a positive feedback loop is that engineers benefit directly from their activities through increased food resources.

As forests in southeast Australia continue to face pressures from climate change, land use transfers and fire frequency increases, it is becoming increasingly important to understand the ecological role of native species like Superb Lyrebird. Their agricultural activities may be key to maintaining the resilience and biodiversity of these threatening ecosystems.

For ordinary forest visitors, seeing the sights of horse chestnuts scratching on their leaves now have new meanings – not only foraging but also farming within the forest range, a complex agricultural system that most likely has been operating for thousands of years before humans noticed it happened.