Endangered Carnaby's Cockatoos Exposed to High Pesticide Levels in Western Australia

Scientists tracking endangered Carnaby’s black cockatoos across Western Australia’s Wheatbelt over three breeding seasons found worrying levels of chemical contamination in the birds' food. Four out of five seed samples tested positive for pesticides, with some containing chemical levels hundreds of times above legal limits. The study, led by researchers at Murdoch University, combined satellite tracking data with seed samples collected near grain silos. The team found 26 different pesticides in the birds' feeding areas, including 10 neurotoxic chemicals, showing that the endangered cockatoos are regularly eating a dangerous mix of agricultural pesticides. Lead researcher Zoe Kissane, a PhD candidate at Murdoch University's Harry Butler Institute, fitted wild cockatoos with GPS and ARGOS satellite tags across five breeding sites. The tracking data showed exactly where the birds were feeding, allowing researchers to collect seed samples from those locations for laboratory testing. The results showed that about 80 per cent of all seed samples contained at least one pesticide, while more than half contained a mix of three or more different chemicals. "Around 80 per cent of seed samples contained one or more pesticide, and many samples contained mixtures of multiple pesticides rather than a single compound," Ms Kissane said. "Additionally, some pesticide concentrations were also well above the acceptable maximum residue levels set by regulatory authorities, in some cases hundreds of times above what is considered acceptable in food and animal feed." "It really highlighted that there's a bit of a chemical cocktail that these birds are being exposed to," she added. "These hazards are out there and it's not just wildlife, but also humans that are potentially at risk. That was quite alarming."

The findings may help explain a long-running mystery affecting black cockatoos in Western Australia. Since around 2012, many birds have developed Carnaby’s Hindlimb Paralysis Syndrome (CHiPS), a condition that causes severe leg weakness, slow movement, and eventually complete paralysis. Scientists have long suspected that agricultural chemicals could be linked to CHiPS, but until now there was no field evidence connecting the birds' movements with contaminated food sources. The researchers found several neurotoxic pesticides in the spilled grain, including imidacloprid, thiamethoxam, clothianidin, difenoconazole, and metalaxyl. These chemicals are known to cause both short-term and long-term health problems in animals and humans. The GPS data also showed that the cockatoos repeatedly returned to the same contaminated feeding sites, increasing the risk of long-term exposure to these chemicals. "That was quite alarming because birds would continue to go back to sites that had chemical pesticide residues at them," Ms Kissane said. "There's that increased risk then of continual chronic exposure to these substances." "These results point to specific pesticides that may be contributing to CHiPS, providing us with new insight," she noted.

Senior Research Fellow Dr Jill Shephard, who co-supervised the project with Professor Kris Warren, said tracking the birds directly to contaminated seed revealed exposure routes that laboratory studies alone could never identify. She said field tracking gives a much clearer picture of how wild animals are exposed to pesticides in real-life conditions. The findings have led to fresh calls for Australia to review its pesticide regulations. Several of the chemicals found in the Wheatbelt seed samples are still widely used in Australia, even though they have been banned or heavily restricted in the UK, Europe, and North America because of concerns about human health and environmental safety. "Many pesticides still in use in Australia are already restricted or banned in parts of Europe, the UK, and North America due to concerns about human and wildlife health, and our results suggest these risks may also be relevant in Australian agricultural landscapes," Ms Kissane said.

The research team said simple changes by the farming industry could greatly reduce the risk to wildlife. Because cockatoos feed on grain spilled during transport and storage, improving grain handling around silos and trucks could quickly reduce their exposure to contaminated food. "From an industry perspective, relatively simple changes, such as improving grain handling practices at silos to minimise seed spills and minimising wildlife access to these spills, could help reduce exposure risks for wildlife," Ms Kissane said. She suggested regularly cleaning up spilled grain around silos and introducing stricter rules for grain transport trucks to stop grain from leaking onto roadsides. "At the same time, I hope it encourages constructive conversations about alternative agricultural practices that reduce reliance on pesticides, lower risks to wildlife, and support healthy ecosystems," she added.