Due to their large size and great beauty, macaws make excellent flagship species and serve as charismatic focal points for the conservation of the ecosystems where they occur. Unfortunately throughout most of tropical America large macaws have suffered major population declines. The Tambopata Macaw Project was begun in the 1989 under the field direction of Eduardo Nycander with the goal of learning about the basic ecology and natural history of large macaws so that this information could be used to help their conservation. In 1999 I took over the direction and operations of the project. The project is developing and evaluating techniques for increasing reproductive output of wild macaws, expanding our knowledge of macaw nesting behavior, increasing our understanding of the complexities of clay lick use, tracking macaw movements through satellite telemetry, and evaluating tourism as a method of protecting macaws and their habitat. This scientific information is being dispersed through a variety of channels to local native communities, to the Peruvian government, and via the Internet to classrooms and conservationists world-wide.
Why are Macaws in trouble?
The reasons for macaw decline are many and include habitat loss and collection for the pet trade. Habitat loss may take many forms including clearing for agriculture and selective logging. Selective logging usually leaves much native vegetation standing including many important macaw food species, but can severely impact macaws because the harvest often targets the old, large trees that the macaws depend upon for nesting. These slow growing trees may take centuries to attain sufficient size to harbor cavities. The deep, dry nest cavities that the macaws prefer may take an additional 10 – 20 years to form but then last for many decades. Even in virgin forest these large tree cavities are usually in short supply. As a result, each nest site cut represents not just the loss of a single nest, but also the loss of dozens of future chicks that could have been raised in this cavity. Collection for the pet trade further exacerbates this shortage of nest sites because in many areas collectors cut the nest trees in order to remove the macaw chicks.
The threats faced by large macaws are compounded by the fact that these species have naturally low reproductive rates. Previous work by the researchers in Tambopata have shown that the low reproductive rates are due to several main factors: 1) there are not enough suitable nest sites even in pristine old-growth forest hundreds of years old, 2) only about 60% of nests fledge young, 3) many natural nest sites suffer higher failure rates because they are either too shallow or wet and 4) successful nests usually fledge only one or two young even when three or four eggs are laid because one chick monopolizes the food deliveries and the others die of malnutrition.
Given the threats that face many macaw populations today, it is obvious that protecting large tracts of habitat is vital to the survival of macaws and the thousands of species that share their habitat. Some of the most important areas to protect are clay licks. Here hundreds of individuals of up to 17 species congregate daily to descend to the river and stream banks to eat clay. This clay apparently provides an important source of sodium, which is chronically lacking in the foods the birds eat daily. The fact that macaws return regularly makes them particularly vulnerable to hunters in these locations. For example, groups of up to 200 or more may frequent large clay licks such as those along the Tambopata and Madre de Díos Rivers in southeastern Peru (pers. obs.). The same predictability that makes clay licks good sites for hunters also makes these locations ideal sites for tourism. As a result, a string of ecotourism projects have sprung up in the last decade that offer macaw viewing at clay licks as a central part of their itineraries. Significant areas are currently being protected from hunting and logging by these ecotourism companies because these tourism projects have a vested interest in protecting the nests and clay licks near their lodges.
Despite the fact that western scientists have known about clay lick use for over thirty years, our knowledge of clay lick use is still far from complete. In general there is still debate over why birds use the clay licks. While there is documented evidence that the clay in the soil can reduce the absorption of dietary toxins in to the blood, there is little evidence to support that the birds choose to consume soils based on their ability to protect from toxins. Instead, there is mounting evidence that the soils provide an important source of sodium. Our studies have begun to unravel some mysteries. We have found that predation is likely driving the time of day in which the birds use the lick and the complex social interactions among different species seen when using the lick. We have also found that the birds use the lick most during the season in which they are nesting, in large part because they feed clay lick soil to there chicks. We still lack information on how often macaws and parrots return to clay licks, how far the birds range to visit licks, and if they shift between licks on a daily basis. This sort of basic information is vital to our understanding of clay lick use and must be obtained if we want to effectively protect clay licks and understand the impacts of tourism.
While there is little doubt that ecotourism is less damaging to macaw populations than hunting and logging, studies documenting the impact of tourism on macaws and parrots at clay licks are lacking. Tourism impacts may be manifested in a variety of ways. Macaws are a favorite of tourists throughout the areas where they occur. Particularly valued by tourists are close range sightings that allow good photo opportunities. Tourist groups frequently observe the clay licks from boats as they pass by or from blinds and trails adjacent to the licks. Groups also approach macaws perched in the trees waiting to descend to the licks. Using as a starting point the basic information on the behavior of parrots and macaws at clay licks, the effects of these sorts of tourism visits must be evaluated so that recommendations can be made on how to reduce the disturbance to the birds.
Unfortunately, due to the naturally low reproductive rates of macaws, just protecting habitat may not be enough to allow them to recover from the decades of collection and tree cutting. For this reason, a major objective of this project is to develop and evaluate different methods to increase the reproductive success of large macaws. We have designed new nest boxes for macaw species that have never nested in artificial nest substrates and conducted experiments and observations aimed at understanding why some macaw chicks die of starvation and how to enhance their survival. Our findings are being shared with conservation scientists worldwide and the personnel of SERNANP (the branch of the Peruvian Ministry of Agriculture in charge on natural resource management). This will ensure that the basic set of tested macaw management techniques developed here arrives in the hands of the people most able to use the information to help the recovery and maintenance of macaw populations throughout the tropics.