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Skip to Macaw Biology in Manu National Park, Peru

My ongoing work with macaws as flagship species for ecosystem conservation has continued to expand in Peru, Bolivia, and Brazil over the past few months, with especially exciting results in the Lower Urubamba River (way downstream from Peru's famous Machu Picchu), in the new and amazing Madidi National Park in Bolivia, and in the dry forests of the cusp between the extreme eastern Amazon and arid northeastern Brazil.

In the Lower Urubamba, we are working with a friendly and cooperative community of 400 lowland Amazonian Indians from the Machiguenga ethnic group. This community, which is called Timpia ("tim-PEE-a"), owns about 70,000 acres of prime foothill rain forest just western of Peru's famous Manu National Park (see Jan '94 National Geographic, "Spirits of the Rainforest" from Discovery Channel, or PBS-TV's latest Manu program from November 1997--available on video). Timpia unilaterally banned all hunting and capture of macaws and other parrots in 1995 to try to attract WCS to support conservation education and field work in their forests. Thanks to WCS's excellent relationship with this community, the Indians showed us a spectacular macaw clay lick hidden along a stream in the middle of their community lands and encouraged us to start research and photo tourism there. The lick is a 200-foot-tall reddish clay bank set back 300 feet from a small, knee-deep stream that is unnavigable due to numerous small rocky rapids. After having seen perhaps 25 of the best macaw and parrot clay licks in southern Peru, I can say that the Timpia site may turn out to be the most photogenic macaw lick of them all. Most large macaw licks have only one or two species of large macaws, but this one has all three of the large lowland species found in the Western Amazon: Scarlet, Green-winged, and Blue-and-Gold. The only other large macaw clay lick that we know of that has all three species is the Tambopata lick further south in Peru. The Tambopata site, however, is extremely hard to photograph safely because the birds eat clay half way up a 120-foot-tall clay bank that itself regularly collapses dramatically into the rushing current of the 400-foot-wide Upper Tambopata River. You can't snap pictures safely from the top of the bank because it is undercut by river erosion and collapses at unpredictable intervals. Forget photos from the opposite shore--the river is too wide to get good shots. In Timpia, the lick bank is even taller, but there are some trees growing on terraces on either side of the lick--a perfect site for permanent photographic blinds. If our work in early 1998 shows that these terraces are firm, then it might be possible to erect guyed metal observation towers near the lick face to permit excellent photo opportunities for visiting scientists, photographers, film makers, and general macaw fanatics. The dramatic foothill scenery in Timpia and adjacent areas is more striking than that in either Manu or Tambopata, which makes Timpia even more promising for tourism. And the community already owns a long, wide, grass landing strip that is a mere seven minutes by boat and 50 minutes on foot from this secluded macaw lick. A WCS partner group in Peru, InkaNatura, has obtained support from the John D. and Catherine T. MacArthur Foundation to work with the community in building a simple 20-bed biological station to offer researchers and photographers from Peru and abroad a unique educational experience. The station will be 100% owned by the community itself. My work in Timpia is supported by the Liz Claiborne and Art Ortenberg Foundation and by the Disney Corporation.

In Bolivia's huge new Madidi National Park (the size of New Jersey), I had the good fortune of leading a National Geographic expedition through the park for four weeks in October 1997. Our team found the park, which WCS played a major role in creating, to be even more amazing than expected. Several times between 1992 through 1996 I surveyed macaws and other wildlife in the lowland rain forest of the park, but this October trip was my first to the high and middle elevations. Madidi starts at more than 19,000 feet--in towering snow-capped peaks covered with massive glaciers. Near the glaciers we saw Andean Condors, Viscachas (incredibly cute, long-eared, relatives of the chinchilla) and fresh signs of Puma. The park then descends rapidly through Andean grasslands, moist cloud forest, lower mountain forest, and parched, deciduous rainshadow valleys to lowland rain forest and seasonally flooded lowland savannahs, the latter at a mere 600 feet of elevation. In the cloud forests we found several large display grounds of the blazing scarlet Andean Cock of the Rock. Madidi is estimated to harbor 1,100 of the 9,600 species of birds in the world---about 100 or so more than the Manu Park, which reaches only about 13,000 feet of elevation and has no snowcapped peaks or glaciers and no lowland savannahs. In fact, Madidi Park is now acknowledged to be the most biologically diverse protected area in the world, thereby stealing the crown from Manu, which held the record for 23 years. The king is dead. Long live the king.

In the middle elevations, we recorded rauchous flocks of endangered Military Macaws, while in the lowlands we marvelled at the tameness and majesty of families of Red-and-Green Macaws, who repeatedly flew within 20 feet of us at eye level as we gazed out over the lowland forest from a forested plateau perched atop a 300-foot-tall macaw nesting cliff. The macaws at this last site are very tame thanks to five years of fierce, on-site protection by the WCS partner group "Eco Bolivia", which expertly organized the complex logistics for our trek. Eco Bolivia, which is composed mostly of lowland Indians of the Tacana ethnic group, is the leading on-the-ground conservation organization in Madidi, and enjoy support from the Liz Claiborne and Art Ortenberg Foundation and the Disney Corporation through WCS, the John D. and Catherine T. MacArthur Foundation, the W. Alton Jones Foundation, the Macaw Landing Foundation, and the Ashoka Foundation, among others. In 1998 and beyond, WCS supporters will be hearing much more about Madidi, because even after numerous expeditions to high and low elevations of the park, we still are just barely scratching the surface in what is perhaps the world's most complex reserve.

For instance, on this last trip, I was amazed to discover that all information and local informants point to the possible existence in the low mountains of the very heart of the reserve of a "lost world" of 150,000 acres or more of tropical forest that may NEVER have been inhabitated by humans, and still is not. What might be living there? No one knows. Stay tuned.

Turning now to the greatest of all parrots, the mighty Hyacinth Macaw, in mid and late 1997, my work with these fabulous birds yielded exciting new discoveries and opportunities in the greatest of all tropical countries: Brazil. Working with our partner group "BioBrasil Foundation" (sic) and in collaboration with Focus Tours (formerly of Minnesota, now of Santa Fe, New Mexico), I had the pleasure of showing to 18 macaw fanatics hidden in a large blind a flock of 70 Hyacinth Macaws eating palm nuts in the wild at eye level in golden morning sun at a distance of 50 feet. This spectacle, which I couldn't believe until I saw it, was ingeniously orchestrated by BioBrasil's team of rustic macaw experts, who are former macaw trappers turned conservationists and ecotour technicians. The 18 visitors were an organized ecotour from the Kaytee Avian Foundation (KAF), which is based at Kaytee Products in Chilton, Wisconsin. This latter company is the world's largest producer of scientifically-designed macaw and parrot diets, backyard bird feeding products, and small mammal diets. KAF is the major supporter of this conservation project for Hyacinth Macaws in Brazil, with additional support coming from the Macaw Landing Foundation, the World Parrot Trust, the International Aviculturists Society, and Natural Encounters, Inc, a leading designer of theme park and zoo spectacles involving free-flying birds of prey and macaws. As a result of the success of this project, which has stopped all trapping of Hyacinth Macaws in a large region of dry northeastern Brazil (the southern part of the state of Piaui), BioBrasil is now moving forward with plans to create the world's first Hyacinth Macaw Reserve through the purchase of a key plot of 5,000 acres at perhaps 25-35 dollars per acre. The Hyacinth Macaw Project will appear soon in a major European nature magazine, and macaw lovers everywhere are encouraged to support this project through WCS or any of the other groups mentioned and to visit the project soon--the climate is spectacular--no biting bugs, no tropical diseases, plenty of ice cold beer and warm Brazilian sun----and tons of macaws. What more does a person need?

Finally, Focus Tours and WCS have teamed up to advise local ranch owners in Brazil's famous wildlife mecca--the Pantanal--on how to implement scientifically-designed photo ops for their numerous Hyacinth Macaws--which gather in flocks of 15-40 in two keys spots discovered by the famous Brazilian parrot biologist Carlos Yamashita and the accomplished tour leaders of Focus Tours. This project is just getting underway, and will be an excellent complement to the BioBrasil Hyacinth Macaw Project described above.

Any WCS members or macaw fans who wish to comment on these or other of my macaw projects are encouraged to contact me through WCS or the Macaw Landing Foundation, and I will respond as soon as possible when I return from field work.

Macaw Biology in Manu National Park, Peru
by Charles A. Munn

Despite their colorful plumage, their popularity as pets, and steep population declines throughout their ranges (Ridgely 1981), very little is known of the biology of any of the 17 living species of macaws (ef. Forshaw 1978). Yet, unless we understand their wild biology, we may not be able to avoid the extinction of species after species of these spectacular New World parrots.

Working since 1985 with a number of Peruvian, Brazilian, and North American assistants, I have studied aspects of the basic biology of the seven species of macaws found in the large, pristine Manu National Park in the Amazonian forest of SE Peru. The principle goals of the first three years of study have been to determine 1) the diets of the macaws and of the other parrots species in the region, and 2) the nesting success of large macaws in undisturbed Amazon forest. Here I present some preliminary results of the work.

Study Area and Methods

The study site is at 71 19’ W, 11 51’ S (elevation ca. 400 m) in undisturbed rainforest at the Totoracocha Biological Station in the Manu National Park. The Park includes portions of the departments of Cusco and Madre de Dios in SE Peru.

Though most of the field work during 1985 was in floodplain terrain within 4 km of the Totoracocha Station, in 1986 through 1987 we studied nesting macaws as much as 20 km upstream and 30 km downstream along the Manu River.

So far, we have conducted most of the research in the 6 km wide floodplain of the Manu, while recently we also have worked in hill forest 50 meters above the floodplain (Fig.1). The floodplain terrain is flat, except for gentle depressions and rises left from ancient changes in the course of the river, which is 180 m wide.

In the rainy season from November through April, flooding occurs in low areas near the river and in shallow depressions in the forest. The study area is primary tropical forest. In the floodplain, occasional very tall trees (“emergence”) rise to 60 m, while the more or less continuous canopy of tall trees is at 30-45 m. Below the canopy are several tree layers (Richards 1952, Terborgh 1983). Even off the trails we could walk easily through the understory in the floodplain, except where trees had fallen. The more tangled, viney understory in the hill forest made walking off the trail much more difficult there.

To collect data on macaws and other parrots, we cut and repeatedly patrolled scores of kilometers of trails at a variety of sites along the Manu River, systematically searching for resting or feeding birds. Using a sighting compass, we frequently left the trails to investigate possible parrot activity.

Although parrots are famous for their loud vocalizations, when in the wild in Manu they are very quiet, or even silent, during most of their waking hours. Only during the hour or so after dawn, while preening or playing in the safety of tall trees during midday, while flying, and in the hour before dusk, did they vocalize loudly. Therefore, the best methods for finding feeding macaws and smaller parrots were to look for the characteristic parrot beakmarks on fragments of discarded seeds and fruits on the ground, and by listening carefully for the falling of these fragments from above. Rarely did feeding parrots vocalize loudly and frequently, but if we waited for long periods near spots where debris was falling, parrots eventually gave themselves away with quiet or loud calls. Frequently, however, they only called in the last seconds before flying from the tree and leaving the area. Very careful scrutiny was necessary to locate silent, feeding birds.

Both to allow us to scrutinize the crowns of tall trees and to afford good views of the details of parrot feeding behavior, we used a tripod-mounted Questar Field Model Telescope with a 32 mm eyepiece, two tripod-mounted 15-60x Zoom 60 Bausch & Lomb Balscopes, a pair of 15x60 mm Zeiss binoculars mounted on an extra-tall Gitzo reporter industry tripod, and four pairs of 10x40 T* Zeiss binoculars. Furthermore, a professional television crew from SUPERFLOW/Aerie Productions donated their time and equipment (which included a tripod-mounted Sony Betacam TV and assorted lenses) to help document parrot behavior and ecology for us. The Questar and the Sony Betacam TV Camera were the only devices that permitted us a close-up view of macaws feeding in the crowns of tall trees.

To monitor the movements of nesting macaws, we used tall, emergent trees as natural observation towers. To climb these trees, we shot lead fishing weights on fishing line over strong branches in the tops of the trees. To propel the lead weights, we donned safety equipment and used Wrist-rocket slingshots or a custom-designed giant slingshot made from several meters of latex surgical tubing tied to a Y-shaped army surplus backpack frame that itself was mounted at the end of a 4-meter-long pole.

After using the fishing line to pull over a stronger line, we then finally pulled over a long, continuous length of Blue-water II static climbing rope and climbed that with standard Jumar ascenders and a Troll Climbing Harness and sat for two to ten hours per day in a bosun’s chair suspended from the rope by prusik knots.

Thousands of stingless bees and scores of stinging bees and wasps surrounded me for the entire time up in the trees, so I had to use a head-net to reduce the number of bees per minute that crawled into my eyes, ears, nose, and mouth. Using the 15x60 and 10x40 T* Zeiss binoculars (hand-held) and even the Questar telescope on a tripod (on wide branches of one particular tree), I was able to follow two pairs of parent birds as they left their nests to forage in the forest within a few kilometers of their nests. I recorded their compass headings and time aloft during their straight foraging flights to estimate the distances and directions ranged.

A caution: one should study these techniques carefully and practice a lot before attempting to shoot lead weights or the climb trees. Many of the details of the rope-climbing techniques are reviewed in Perry and Williams (1981) and Whitacre (1981).

Finally, whenever I traveled on the Manu River or other rivers in the neotropics, I continually censused macaws and other large animals, noting the species, the activity (flying, perched, etc.), the total number in each group, the number in each subgroup (which may be very useful for macaws and other parrots), the time of day, the weather, the kind of boat in which I was traveling, how the boat was propelled, when I started the census (usually when the boat started moving), when I stopped, the approximate speed with which I traveled, the width and sediment load of the river, and my approximate range of vision. The data from such censuses permitted a relative comparison of macaw density in different regions and may also tell us how long juvenile macaws traveled with their parents in the wild or whether group sizes varied with the reproductive cycle.

Results and Discussion

Macaw Diets. The large macaws of Manu eat a wide variety of seeds and fruits from trees and vines in many botanical families (Table 1). The list of food items for the most common species of macaws in the lowlands, namely the blue-and-yellow (Ara ararauna), the scarlet (A. macao), the red-and-green (A. chloroptera), and the chestnut-fronted (A. severa), is only partially complete at this stage, while the list of food items for the other three species, the red-bellied (A. manilata), the blue-headed (A. couloni), and the military (A. militaris), is very incomplete and will require several more years of work.

The blue-headed macaw reportedly is more common closer to the foothills of the Andes than in the floodplain forests of the meandering Manu River, while we know that the military macaw inhabits the foothills and lower ranges and valleys of the Andes, where we have not yet worked.

The macaws of Manu eat the seeds of many fruits (Table 1), sometimes eating the surrounding pulp as well, but other times rejecting the pulp (e.g., Spondias mombin, Anacardiaceae; Table 1). In some cases they reject the pulp (e.g., Borismene japurensis, Menispermaceae) and they also eat flower nectar, leaf petioles, and mature leaves (e.g. Iriartea ventricosa, Palmae) and probably other plant parts not yet observed.

A sizable number of their food choices are dry seeds that normally would be dispersed by wind or water, such as the winged seeds of valuable lowland species of mahogany (Cedrela odorata, Meliaceae) and of the common floodplain tree, Terminalia oblonga (Combretaceae). They also may be the only vertebrate predators of the seeds of the explosively dehiscent (splitting-open) fruit of the soapbox tree (Huracrepitans, Euphorbiaceae).

Generally speaking, the dominant impression we have about macaw diets at this point is that they are extremely varied--running the gamut in hardness and palatability from small, soft figs to large, hard palm nuts and bitter seeds of Cedrela odorata. Interestingly, Janzen (1983a,b) suggests that the seeds of Cedrela odorata are not eaten by any species of animals in Costa Rica, but this apparent immunity to macaw attack might actually reflect the current scarcity of both mahoganies and macaws in that county.

One noteworthy aspect of macaw food choices is the birds’ tendency to eat (predate) the seeds of slightly unripe fruits (Table 1, e.g., Cedrela odorata, Terminalia oblonga, Spondias mombin, etc.), which may help them to compete successfully with the many other species of frugivorous animals for the finite fruit resources.

After all, if the macaws waited until fruits were fully ripe, often the seed dispersal agents, whether animate or inanimate, would reach the fruits before the macaws, thereby scattering the seeds they desire.

Eating seeds, which often are protected by distasteful or even toxic secondary compounds (Balandrin et al. 1986), and eating or cutting through unripe, tannin-rich pulp on unripe fruits (Wrangham and Waterman 1983) may be the reasons why macaws and most of the other species of parrots in Manu eat clay daily on favorite clay banks on the Manu River and on small tributary streams of the Manu. This clay might help absorb or filter out these distasteful or toxic compounds from their diet, much as vintners use clay to filter out some of the bitter tannins from red wine, and highland Indians in the Andes grind clay with the bitter wild potato to bind toxic alkaloids and thus render the poisonous tuber edible (Johns 1986). I am now analyzing the nutrients and secondary compounds in oven-dried samples of macaw foods and the minerals and detoxifying abilities of macaw clays from Manu and will report on those finds in the future.

Observations of Macaw Nests. Over the past three years, we have followed the outcome of eight nest of large macaws: three of blue-and-yellow; three of red-and-green; and two of scarlet (Table 2). Overall, three were successful, and five were unsuccessful. These data are the fist on macaw nesting success in a large, undisturbed, protected area anywhere in the neotropics, and as such they must serve as a baseline for comparison with further data from Manu and data from other regions.

Observations of Diets and Ranging Patterns of Two Nests of Blue-and-Yellow Macaws in 1986.

Hanging by harnesses and sitting on branches up to 45 meters above the ground on a ridge that, itself, rose 60 to 80 meters above the adjacent floodplain forest, in 1986, I observed two blue-and-yellow macaw nests for several weeks. From one favorite perch I could see 2 to 70 km, depending on the direction. Both macaw nests were in the floodplain at 700 and 900 meters, respectively, from my lookout tree.

With the Questar on a tripod and the 15-power binoculars, I observed the routes of the adults when they left the nest trees in search of food. Two assistants of mine, David Rivaled Rio of the University of Cusco, Peru and Beatrice Ribeiro do Vale, a Brazilian master’s candidate at the National Agrarian University at La Molina, Peru, watched the two nests from the beach of the Manu River and informed me by walkie-talkie radio each time the adults flew.

Using these methods we were able to determine that most flights were 300 to 2,000 meters in length. When the birds reached a fruit tree, they ate for 10-35 minutes in a tree before flying 400-500 meters to another tree in the same general patch of forest.

Occasionally, they flew more than two kilometers in one direction and disappeared, but full analysis of the data should show that most of the flights were within a range of two kilometers of the nests. Non-nesting birds, of which there were many more than the two nesting pairs, tended to fly farther and disappear from the area with greater frequency.

On several occasions we were able to follow macaws several hours as they "traplined" a series of fruit trees in a two-square kilometer peninsula of forest that was bordered on three sides by a long loop of the Manu River. During a period of four hours, for example, the adults of one nest ate the pulp of Slovene obtusifolia (Elaeocarpaceae), then flew 250 m to an emergent Dipteryx alata (Leguminosae) and preened for 45 minutes before then eating the rich mesocarp of more than a dozen palm fruits (Scheelea cephalotes). Also eaten by the adults from these nests during the nesting period were the leaf petioles of Ficus ypsilophlebia (Moraceae), the seeds of two legume trees (Palmae, immature seeds of Spondias mombin, arils of Otoba parvifolia (Myristicaceae), and others.

What impressed us the most was that the adults usually flew relatively short distances (150-300 m) between the various trees that they were exploiting. We had thought that perhaps such large birds obviously capable of flying long distances with apparently little effort would fly further in search of food. Of course, from the top of the trees, I saw blue-and-yellow macaws and other species fly straight for as long as five to eight minutes before landing or becoming invisible in my binoculars. Generally, however, even non-nesting birds flew an average of only about 400 to 800 meters with each flight.

Our understanding of ranging patters of macaws is still crude, but now we know that one can gather useful data from treetop lookouts.

Low Reproductive Rates.

Of the 20 or more pairs of blue-and-yellow macaws that appeared daily in the area of the two 1986 blue-and-yellow nests (each individual has unique black feather lines on the side of its face that can be sketched easily when seen through a Questar telescope), only two pairs were nesting. We could be reasonably certain that most pairs were not nesting because the two nesting pairs had quite obviously delayed molt. Their body feathers appeared dirty and tattered, as did their tails and wings. All the other pairs had brilliant yellow breasts and superbly blue wings, tails, and backs.

Furthermore, the crops of the nesting birds (in which they carry food back to their nestlings) were frequently grotesquely distended while the crops of the other pairs were not nearly so large.

Finally, though these observation of the blue-and-yellow ness in 1986 were from the very end of the wet or nesting season (they coincide), none of the apparently non-reproductive birds were accompanied by supernumerary birds with short tail and dark irises (the field marks of fledgling macaws). Of course, some may have tried to reproduce and failed, but the fact remains that only one out of perhaps twenty adult pairs had successfully reproduced in 1986.

These breeding data and our continual year-round censuses of flying blue-and-yellow, scarlet, and red-and-green macaws suggest similar low reproductive rates for all three large species. Very few of the mated pairs that we saw flying over the river were accompanied by one or two additional birds (presumed offspring). We can only conclude that these first data on macaw reproduction in the wild suggest strongly that macaws may have very low reproductive rates even in large, virgin, completely protected floodplain forests where the annual fruit production appears to be far higher than in most of the rest of Amazonia (Terborgh 1983).

If future data from our project in Manu and from other studies prove that even under the best of conditions wild macaws reproduce glacially slowly, than the harvest of wild macaws will have to be controlled much more tightly if macaws are to survive in the wild. Fortunately, recent reports from expert aviculturists suggest that macaws can reproduce 10 to 30 times faster in captivity than in the wild, so efficient captive breeding may be an important part of any successful plan to conserve wild population of these, the world’s largest parrots.

Charles A. Munn
Wildlife Conservation International
New York Zoological Society
Bronx, New York 10460
UNITED STATES

Acknowledgments

Wildlife Conservation International, a division of New York Zoological Society, funded the entire project since its inception.

I thank A. Huaman L., B. Baca r., L. Quinones V., P. Nunez, C. Capac, A.M. Edwards, B. Gomez L., G. Helsaple, M. Helsaple, J. Iparraguirre, P. Manice, M. Munoz, K. Petren, B. Ribeiro, Dr. Ricalde R., K. Timmons, K. Wehr n., N. Williams, R. Williams, M. Williamson, W. Wust, and others for assistance in the field; C. Mitchell, J. Terborgh, G. Russel, and others for sharing observations made during other field work, R. Foster and A. Gentry for plant identification, and numerous other support personnel who have made the project possible.

I am grateful to the administration of the Manu National Park, which is a project of the Corporation for development of Madre de Dios, and the Direccion General Forestal y de Fauna of the Peruvian Ministry of Agriculture for permission to conduct the research.

Finally, I thank my wife, Martha, and my daughter Charlotte, for cheerfully enduring my long absences in the field.

Literature Cited

Balandrin. M.F., J.A. Klocke, E.S. Wurtele, and W.H Bollinger. 1986 Natural plant chemicals: sources of industrial and medicinal materials. Science 228:1154-1160

Forshaw, J. 1978. The Parrots of the World. 2nd ed. Lansdowne Editions, Melbourne.

Janzen, D.H. 1983a. Ara macao (Lapa, Scarlet Macaw). In: Costa Rican Natural History. D.H. Janzen, ed. University of Chicago Press, Chicago, IL, pp. 547-548

Janzen, D.H. 1983b. Brotogeris jugularis (Perico, Orange-chinned Parakeet). In: Costa Rican National History, D.H. Janzen, ed. University of Chicago Press, Chicago, IL, pp. 548-550

Johns. T. 1986. Detoxification and domestication of the potato. Journal of Chem. Ecol. 12:635-646.

Perry. D.R., and J. Williams. 1981. The tropical rain forest canopy: a method providing total access. Biotropica 13:283-285.

Richard, P.W. 1952. The Tropical Rain Forest. Cambridge University Press, Cambridge, England.

Ridgely, R.S. 1981. The current distribution of status mainland neotropical parrots. In: Conservation of New World Parrots, R.F. Pasquier, ed. Smithsonian Institution Press, Washington, D.C. pp. 33-384.

Terborgh, J. 1983. Five New World Primates: a Study in Comparative Ecology. Princeton University Press, Princeton, NJ.

Whitacre, D.F. 1981. Additional techniques and safety hints for climbing tall trees, and some equipment and information sources. Biotropica 13:286-291.

Wrangham, R.W., and P.G. Waterman. 1983. Condensed tannins in fruits eaten by chimpanzees. Biotropica 15:217-222.

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