New World Parrots Still in Crisis

Alan Lee Since the publication of “New World Parrots in Crisis: Solutions from Conservation Biology” (Beissinger and Snyder 1992), a recent review of parrot related literature shows that little has changed for parrots to alleviate their “crisis”. In fact, in several respects their situation only seems to have deteriorated. Most seriously, tropical parrots, like all birds worldwide, face continued loss of habitat through destruction of tropical rainforests, the consequences of which can be seen in the rapid avifaunal collapse along the “Amazonian deforestation frontier”. But parrots have additional threats to contend with. Among the old threats that still exist is continued over-harvesting for the pet trade. Poaching of parrot nestlings for economic gain is a widespread and biologically significant source of nest mortality in Neotropical parrots. This is the case for many Neotropical species and in northern Peru around Iquitos this has had severe impacts on populations of Blue-and-Yellow Macaw (Ara ararauna), Scarlet Macaw (Ara macao) and Orange-winged Parrots (Amazona amazonica). Up to 680 birds are harvested from one site alone in that area, where collectors normally cut down the nesting tree or opening a hole in the trunk to reach the nest cavity. This is unsustainable as nest-trees become useless and the next generation is completely removed. The availability of suitable cavities is thought to form a severe population bottleneck in the recovery ability of larger species. The highest daily incomes of communities in that area between 1994 and 1997 came from the extraction of ornamental fishes, turtle eggs and young macaws and parrots (US$ 10-30 per day), so unsustainable harvesting is an attractive source of income compared to agriculture and day labour that resulted in an average daily earning of $5 and $3 respectively. The need for sustainable industries, like tourism, cannot be highlighted enough in this context due to the benefits that could be derived in the form of local income, not to mention for the conservation of the surrounding wildlife. Studies along the Tambopata have identified two keystone plant resources used by nesting parrots: the giant emergent Ironwood (Dipteryx micrantha) and the Aguaje palm (Mauritia flexuosa). Ironwood trees are the tree of choice for many parrot species, but are increasingly logged throughout their range as they are in high demand for hardwood flooring and in Peru people use the wood to make charcoal. Landowners sell trees for as little as US $30. The recent increased harvest in Costa Rica of their local species of Ironwood (Dipteryx panamensis) is the most probable cause for the precipitous decline of Great Green Macaws in that country. Aguaje palms are threatened because local people commonly cut entire trees to harvest weevil larvae and fruit. However, many parrots, game species, and large-bodied seed dispersers that move between the swamps and the surrounding landscape also depend on these fruits and Blue-and-yellow and Red-bellied macaws both rely on old dead palms for nesting sites. The loss of keystone nesting trees through selective logging and the unsustainable harvesting of wild crops is itself a direct threat, but one that may also have consequences on reproductive success as birds are forced to nest in suboptimal nesting sites more accessible to predators. Next time you are on the tower at Refugio Amazonas, consider that some of the pairs of birds flying past may well be homeless and searching for a new, safe place to try and raise a family. Some parrots, such as Ring-necked parakeets in California, have been identified as harmful invasive pest species and in the case of those species control measures may be justified, but in the case of range restricted species the consequences can be dire. For example, the persecution as crop pests of species like the Blue-winged Macaw (Primolius maracana), which has been almost exterminated in Argentina. The fragmentation of the Aguaje palm swamps that provide food for Red-bellied Macaws (Ara manilata) and Orange-winged Parrots (Amazona amazonica) may have led to the persecution of the later as an agricultural crop pest in Trinidad as crops have replaced natural habitats leaving parrots with few other options. The consequences of some species raiding crops can be severe for other species due to accidental persecution in cases of mistaken identity, for instance the Vinaceous Parrot (Amazona vinacea). No current discourse on the plight of parrots would be complete without a mention of global warming, which has been identified as an additional element to the sad plight of the Blue-winged Macaw (Primolius maracana) due possibly to resulting changes in fruiting and flowering regimes. But increased atmospheric carbon could also affect parrots and all cavity nesters by promoting the growth of lianas, which make nesting cavities more accessible to arboreal predators of eggs and chicks such as arboreal boas (Epicrates spp), Tayra (Eira Barbara) and Kinkajou (Potus flavus). Increased liana predominance in the rainforest landscape could also have consequences for food supplies as the Brazil nut (Bertholettia excelsa), a source of food for large macaws and an economically important crop, shows decreased fecundity and yield with increasing liana load. The precarious decline of the Great Green Macaw (Ara ambigua) in western Ecuador has been attributed to food scarcity among other pressures. The Bahaman Parrot (Amazona leucocephala) not only faces threats from fires, development and predators, but hurricanes too and it has been postulated that these will become more regular with global warming as evidenced by Hurricane Katrina and other devastating tropical storms recently. Despite the pessimistic outlook on many fronts conservation action can help. Poaching is significantly lower at protected sites and populations of species that have been threatened can recover, as seen in Indonesia with Citron-crested Cockatoo (Cacatua sulphurea) after a 10 year ban in international trade. About 6km from the outskirts of Puerto Maldonado there is a clay lick now only visited by a few small species of parakeet that still survive in agricultural environments, but once upon a time this may have been as spectacular as the clay lick at the Tambopata Research Centre. Thanks to the establishment of the Tambopata Research Centre the hundreds of parrots and macaws still form the incredible spectacle they do today as they did a hundred years ago and I salute the efforts of Rainforest Expeditions and other tourism companies for the role they have had in the conservation of the parrots, one of the most colourful and charismatic of the bird families in the world. At least some things have been learnt since the flag was first raised on the parrot crisis.