AsianScientist (Aug. 20, 2021) – As the saying goes, the proof is in the pudding—or in the isotope. Using isotope analysis, ecologists from the University of Hong Kong (HKU) can determine whether birds in the pet trade are captive or wild-caught. Their findings were published in Animal Conservation.
In Hong Kong, exotic birds like yellow-crested cockatoos are commonly sold as pets. Though these birds could have been legally raised by home breeders, many are also surreptitiously trafficked from abroad or seized from Hong Kong’s free-flying, introduced population of cockatoos.
However, it is difficult to distinguish a wild-caught cockatoo from their captive-bred counterparts by eye alone—meaning that illegally caught cockatoo can be laundered in the legal market by claiming they were bred in captivity.
Accordingly, there is a need to determine whether an individual bird is sourced from the wild or captive-bred. After all, the outcome could potentially serve as the key piece of evidence in determining whether a trade is legal or not.
Led by Dr. Caroline Dingle, Director of HKU’s Conservation Forensics Laboratory, the team conducted isotope analysis techniques on feathers from Hong Kong’s wild cockatoo population and on feathers from pet cockatoos owned by private individuals to see if dietary differences were reflected in carbon and nitrogen values.
Specifically, the team applied two novel forensic tools: stable isotope analysis (SIA) and compound-specific stable isotope (CSIA), which analyzes isotope values associated with specific amino acids. They found that both stable carbon and nitrogen isotope values differed significantly between wild and captive cockatoos, indicating consumption of different plant and protein types in their diets.
In the future, enforcement officials could apply their test to conclusively determine whether a cockatoo has been raised in the wild or in captivity.
“Legal wildlife trade creates opportunities for the sale of illegally procured wildlife since it is difficult to discern legal from laundered items. Our results show that [isotope analysis] presents a powerful tool for government authorities in their efforts to regulate wildlife trade,” said study first author Dr. Astrid Andersson.
The article can be found at: Andersson et al. (2021) Stable Isotope Analysis as a Tool to Detect Illegal Trade in Critically Endangered Cockatoos.
Source: The University of Hong Kong; Photo: Shutterstock.
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