Monitoring illegal wildlife trade and how the modus operandi of traders changes over time is of vital importance to mitigate the negative effects this trade can have on wild populations. We focused on the trade of birds of prey in Indonesia (2016–2021) in bird markets (12 markets, 194 visits), on Instagram (19 seller profiles) and on Facebook (11 open groups). We link species prevalence and asking prices to body size, abundance and geographic range. Smaller species were more traded in bird markets and less so online. Abundance in trade is in part linked to their abundance in the wild. Asking prices (mean of USD 87) are positively correlated with size and negatively with their abundance in the wild. Authorities seize birds of prey according to their observed abundance in trade, but only 10% of seizures lead to successful prosecutions. The trade is in violation of national laws and the terms and conditions of the online platforms; the low prosecution rate with minimal fines shows a lack of recognition of the urgency of the threat that trade poses to already imperilled wildlife. The shift of trade from physical bird markets to the online marketplace necessitates a different strategy both for monitoring and enforcement.

Indonesia is at the epicenter of the Asian Songbird Crisis, i.e., the recognition that the cage bird trade has a devastating impact on numerous imperiled bird species in Asia. The Javan pied starling Gracupica jalla, only in the last five years recognized as distinct from the pied starlings of mainland Southeast Asia, has been declared extinct the wild in 2021. Up until the 1980s, it used to be one of the most common open countryside birds on the islands of Java and Bali, Indonesia. From the early 2000s onwards, the species is commercially bred to meet the demand from the domestic cagebird trade. We conducted 280 market surveys in 25 bird markets in Java and Bali between April 2014 and March 2020, with 15 markets being surveyed at least six times. We recorded 24,358 Javan pied starlings, making it one of the most commonly observed birds in the markets. We established that, conservatively, around 40% of the birds in the market were sold within one week and used this to estimate that at a minimum ~80,000 Javan pied starlings are sold in the bird markets on Java and Bali. The latter represents a monetary value of USD5.2 million. We showed that prices were low in the 1980s, when all birds were sourced from the wild. It became more varied and differentiated in the 2000s when a combination of now expensive wild-caught and cheaper captive-bred birds were offered for sale, and prices stabilized in the 2010s when most, if not all birds were commercially captive-bred. Javan pied starlings are not protected under Indonesian law, and there are no linked-up conservation efforts in place to re-establish a wild population on the islands, although small-scale releases do take place.

The wildlife trade has facilitated the introduction of invasive non-native species, which may compete with native species for resources and alter ecosystems. Some of these species have great potential to become invasive if released or escaped from captivity. Here we studied the pet trade in a group of open countryside birds, the mynas (Acridotheres spp.) in Indonesia, and identified the areas that are at high risk of facing the establishment of these species. Mynas are among the most invasive birds in Southeast Asia. Once established in a new area, they are almost impossible to eradicate and can have strong negative impacts on the ecosystem. Preventing their introduction is therefore essential. Yet, invasive non-native mynas continue to be traded openly. We present data on the trade in seven species of mynas on Java, Bali and Lombok, with three species being native to parts of one or two of these islands, but not to the remainder, and four that are non-native to the region. From 2016 to 2021 we conducted 255 surveys of 30 animal markets. We recorded over 6000 mynas that were offered for sale outside their native range. Areas most at risk because of their high prevalence in specific animal markets, are Greater Jakarta, eastern Java, Bali and Lombok. The number of invasive non-native mynas recorded was positively related to the size of the animal market. Indonesia is signatory to several international agreements (CBD, ASEAN) that have policies and guidelines to prevent the introduction of invasive non-native species, but compliancy is weak. Annually hundreds and possibly thousands of invasive non-native mynas are released by Indonesian conservation authorities in regions that are outside their native range. Effective management of, and regulation of trade in, potential invasive non-native birds in Indonesia falls short and inadvertently greatly aids both their introduction and establishment.