New research from the University of Adelaide has shown that glossy black cockatoos prefer to feed on trees growing in acidic soil.
Glossy black cockatoos are seed-eating birds that feed almost exclusively on the cones of hanging sheoak trees. Counterintuitively, however, they select trees that grow in the poorest soils found on ancient sedimentary rocks.
“Sheoak trees are three times more likely to be used as a food tree when growing on non-limestone sedimentary rocks,” says Dr Gay Crowley from the University of Adelaide’s School of Social Sciences.
Dr. Crowley compared 6,543 feeding records with 23,484 sheoak records from New South Wales to make this discovery. She found that soil type has a direct influence on how Glossy Black Cockatoos use the environment by comparing Glossy Black Cockatoos’ feeding data against the soil and rocks on Kangaroo Island.
“Sheoaks obtain their nutrition through fungal associations, rather than from the soil, and the associated fungi thrive in poor soils,” says Dr Crowley, whose research was published in the journal. PLOS ONE.
“Many iconic Australian animals, such as bilbies, potoroos, bettongs and bandicoots, feed directly on soil fungi – including native truffles. The same routes are likely responsible for their distribution in the environment.”
Shiny black cockatoos are one of five species of black cockatoos in Australia and are found in eastern Australia and on Kangaroo Island in South Australia. The species is listed as endangered in South Australia and as vulnerable throughout the remainder of its range.
To ensure the long-term survival of species that rely on soil fungi, especially the glossy black cockatoo, Dr. Crowley says conservation efforts must take into account the value of habitats on poor soils.
“Conservation efforts often prioritize the richest, most fertile parts of the landscape. This is because many rare animals, such as greater gliders and powerful owls, are most common in forests that grow on rich soils derived from basalt or limestone,” says Dr. Crowley.
“However, many other animals, such as potoroos, bandicoots and glossy black cockatoos, are best protected by preserving habitats on infertile lands.”
