Species for Sale: Yellow-crested Cockatoo
by Thomas Gomersall
A parrot native to Indonesia and Timor Leste, the yellow-crested cockatoo (Cacatua sulphurea) also exists in Hong Kong and Singapore, descended from escaped pets brought from Indonesia. It is an intelligent, social, long-lived bird that feeds on fruits, young leaves and flowers and nests inside cavities of large, mature trees. Studies of the Hong Kong population suggest that pairs may use the same tree cavity for multiple nesting attempts (IUCN Red List, 2020; Andersson & Dingle, 2020). It is a slow breeder, with females only laying two to three eggs per year (Platt, 2013).
Item on Sale:
Like many parrots, the yellow-crested cockatoo is a popular cage bird, with individuals sold for the pet trade often having been stolen as chicks from their nest cavities. In 2002, the species was upgraded to Appendix I of the Convention on International Trade of Endangered Species (CITES), making it illegal to trade in wild-caught individuals. However, birds that are captive-bred within the country of sale can still be legally traded (Andersson & Dingle, 2020).
Although imports of yellow-crested cockatoos into Hong Kong have seemingly declined since the CITES listing, they are a common pet here and can still be bought in Mong Kok’s Yuen Po Bird Market and in pet shops around the city. According to Yu Yat-tung, Research Manager for the Hong Kong Birdwatching Society, the existence of a legal trade potentially provides a cover for the laundering of wild-caught birds alongside captive-bred ones. “It’s possible that people are selling [yellow-crested cockatoos] claiming they are locally bred,” he said, although it is currently unclear what proportion of the cockatoos for sale in Hong Kong are wild-caught, if any (Andersson & Dingle, 2020).
Price:
Once numbering in the tens of thousands, the global population of the yellow-crested cockatoo has been devastated by the pet trade (Gibson & Yong, 2017). Export data shows that between 1981 and 1989 alone, nearly 62,000 were exported from Indonesia and today, there are only around 1,000 to 2,500 left, fragmented into small, isolated, vulnerable populations (IUCN Red List, 2020).
The pet trade is also very cruel. Smugglers have been known to stuff cockatoos alive inside plastic bottles (Philips, 2015). Not surprisingly, the death rate in transit is very high. Of the 23 yellow-crested cockatoos seized in a highly publicised bust in 2015, only five were likely still alive as of 2019 (Freischlad, 2019). Those that survive long enough to be sold are, to varying degrees, unable to carry out their natural behaviours in captivity like foraging and socialising, threatening their mental as well as physical wellbeing (Engebretson, 2006). Even if cockatoos are rescued, rehabilitation can take years and many never fully adapt to life in the wild (Freischlad, 2019).
How can Hong Kong help?
Regulating the local cockatoo trade requires keeping accurate records of the number of birds imported into Hong Kong, monitoring local breeding efforts, and knowing whether any wild-caught birds are being sold here. University of Hong Kong PhD student Astrid Andersson and supervisor Dr. Caroline Dingle are now developing forensic techniques to obtain this information by measuring the ratio of carbon isotopes in cockatoo feathers.
Carbon isotope ratios (13C/12C) vary depending on the types of plants animals eat and as captive and wild cockatoos have different diets, their carbon isotope ratios should, in theory, differ significantly. If they do, authorities could use this to determine if cockatoos on sale were recently caught from the wild or captive-bred (Andersson & Dingle, 2020). Cracking down on the illegal trade can significantly aid the yellow-crested cockatoo’s recovery in the wild, as the cessation of the pet trade for a closely-related subspecies lead to modest population increases (Cahill et al, 2006).
Public education programmes are needed to help pet owners recognise the harm in buying cockatoos. Indeed, a survey by Andersson of people living in cockatoo habitat in Hong Kong suggests that there is already some public support for such education programmes.
“They appreciate the cockatoos; they’re interested in them. But they don’t have that much knowledge about them. So an educational campaign would probably be quite well-received” Andersson says. “People will be interested that this is a critically endangered species that is dwindling in its native habitat.”
Hong Kong’s own cockatoos — comprising 10 per cent of the global population (Kao, 2017) — must also be protected and studied further. Currently, numbers have plateaued at around 150–200 birds with little sign of growth, which could be due to a lack of suitable nesting sites.
However, as cockatoos can live for several decades, it could also be that the Hong Kong population consists mostly of old birds with limited future breeding potential. In a population this small, there is also the risk of inbreeding and low genetic diversity. All of these things would compromise these cockatoos’ ability to form new populations and their suitability for potential reintroduction programmes. Genetic analyses by HKU will confirm if this is the case, according to Dingle(Andersson & Dingle, 2020). “Just by keeping this population alive, we can contribute to the conservation of this species. But whether they can be introduced back to Indonesia, that’s a more complicated question.”
References:
· Andersson, D. and Dingle, C. (PhD), interviewed by Thomas Gomersall, 2020, The University of Hong Kong.
· Cahill, A.J., Walker, J.S. and S.J. Marsden. 2006. ‘Recovery within a population of the critically endangered citron-crested cockatoo Cacatua sulphurea citrinocristata in Indonesia after 10 years of international trade control’. Oryx, vol. 40(2): 161pp.-167pp.
· Engebretson, M. 2006. ‘The welfare and suitability of parrots as companion animals: a review’. Animal Welfare, vol. 15: 263pp.-276pp.
· Freischlad, N. ‘Indonesia confiscated some 200 pet cockatoos. What happened to them?’. Mongabay, 4 January 2019. https://news.mongabay.com/2019/01/indonesia-confiscated-some-200-pet-cockatoos-what-happened-to-them/ (Accessed: 21 May 2020).
· Gibson, L. and Yong, D.L. 2017. ‘Saving two birds with one stone: solving the quandary of introduced, threatened species’. Frontiers of Ecology and the Environment, vol. 15(1): 35pp.-41pp.
· IUCN Red List, Yellow-crested cockatoo, [website], 2020, https://www.iucnredlist.org/species/22684777/131874695 (Accessed: 22 May 2020).
· Kao, E. ‘Hong Kong a sanctuary for cockatoos driven to the brink of extinction in native lands’. South China Morning Post, 4 January 2017. https://www.scmp.com/news/hong-kong/health-environment/article/2059345/hong-kong-sanctuary-cockatoos-driven-brink (Accessed: 14 April 2020).
· Phillips, T. ‘Critically endangered cockatoos stuffed into plastic bottles by Indonesian smugglers’. The Telegraph, 5 May 2015. https://www.telegraph.co.uk/news/worldnews/asia/indonesia/11583466/Critically-endangered-cockatoos-stuffed-into-plastic-bottles-by-Indonesia-smugglers.html (Accessed: 14 April 2020).
· Platt, J.R., ‘Illegal pet trade wiping out yellow-crested cockatoo’, Scientific American [web blog], 21 March 2013. https://blogs.scientificamerican.com/extinction-countdown/illegal-pet-trade-yellow-crested-cockatoos/ (Accessed: 14 April 2020).
