In October 2013 111 captive Endangered red-and-blue lories Eos histrio were confiscated from a Filipino trader on their native island of Talaud, north of Sulawesi, Indonesia. To prevent them escaping the trader had torn out their flight-feathers, so they were transferred to recover at Tasikoki, an animal rescue centre in Sulawesi, pending their eventual release back into the wild. The Indonesian authorities emphasized the signal such a release would send to the region's trappers and traders: commerce in this species is illegal under national and international law. Thus in August 2014 55 birds (the others having died or failed to recover from their injuries) were duly liberated into forest on Talaud. Most conservation-minded onlookers would doubtless applaud this outcome, not just for the sake of the birds themselves or the species as a whole, but also for that strong conservation message. But what if this exercise sent something else back to Talaud as well?
Parrots regularly carry undetected pathogens such as herpesvirus, circovirus, polyomavirus, bornavirus and chlamydia. Even clinically healthy birds can transmit pathogens both within and between species, causing severe illness, especially in naïve (previously unexposed) populations. Moreover, some pathogens (e.g. herpesvirus) produce weak symptoms in one species but fatal ones in another. As parrots are typically sociable, disease spread can be rapid in both captivity and the wild, mostly by direct contact but even by using the same perches; in captivity airborne transmission may also occur. Detecting all potential pathogens in captive birds is expensive, time-consuming and nigh impossible, as cases can still go undetected, however comprehensive the monitoring. Unsurprisingly, therefore, many pathogens are present in many facilities worldwide. Before or even after confiscation, is it certain those lories were never housed with or near other parrots?
The experts say: ‘Only in the very unusual circumstances where history of disease exposure of confiscated birds is known…, there is a true conservation need…, and there are resources for a comprehensive release programme, is it advisable to utilize confiscated birds in releases’ (Snyder et al., 2000, Parrots: Status Survey and Conservation Action Plan 2000–2004. IUCN, Gland, Switzerland). Even so, although the problem of disease transfer may be getting worse (e.g. Jackson et al., 2014, Emu, 114, 283‒289), the World Parrot Trust recently outlined its ‘release to restore’ plans for several species, sometimes to free confiscated wild-caught parrots in areas from which the species in question have disappeared, but sometimes to release birds that are expected eventually to unite with their wild counterparts.
An example is the proposed release of six Critically Endangered blue-throated macaws Ara glaucogularis into the species' only known area in Beni, Bolivia. World Parrot Trust's PsittaScene (May 2013, 10‒11) argues that, because so few wild birds remain, the release will constitute a reintroduction, not a reinforcement (sensu IUCN/SSC, 2013, Guidelines for Reintroductions and Other Conservation Translocations, v. 1.0), because ‘contact with any wild bird is unlikely to occur soon after release’. But, given that macaws are spiritedly long-distance travellers (e.g. Bonilla-Ruz et al., 2007, Wilson Journal of Ornithology, 119, 729‒732), how small should this unlikelihood be? What constitutes ‘soon’? Confiscated grey parrots Psittacus erithacus released at Lake Victoria were, within 3 months, ‘regularly mixing and flying with a small group of wild birds' (PsittaScene August 2014, 13‒14). If (1) some parrot diseases incubate for many months, (2) some healthy birds are life-long carriers, and (3) some cases escape detection however carefully screened, how confident can we be that releasing the macaws serves the best interests of the species?
When confiscated birds are involved the alternatives are far from pleasant: deployment to zoos for education, life-long care at a centre, or—most depressingly—euthanasia (although this is illegal in Indonesia for threatened species). All the more reason, therefore, that any release programme must observe the highest levels of scrutiny for pathogens (Jakob-Hoff et al., 2014, Manual of Procedures for Wildlife Disease Risk Management. OIE, Paris, France), keeping birds in secure quarantine for 3‒6 months and retesting them at least twice for different diseases according to circumstance. Without such rigour, can the risk posed by captive birds to any targeted wild population—especially if the only population—ever be acceptable?
