Download An Analysis of Macaw Conservation Strategies at the Tambopata

An Analysis of Macaw Conservation Strategies
at the Tambopata Research Center
Brian Leahy
Sophomore College 2013
October 14, 2013
Blue-and-yellow Macaws at the Collpa Colorado
Abstract:
Macaws are becoming increasingly threatened with endangerment and, in
some cases, extinction largely due to poor reproductive rate and progressively
higher levels of deforestation and exploitation. As a way to combat the dwindling
populations, macaw preservation techniques have been implemented in some South
and Central American locations. The Tambopata Macaw Project in the Madre de
Dios region of Peru has been the leading force of this macaw conservation effort.
Their efforts at supporting the proliferation of this species have included the
protection and management of macaw habitat, the construction of artificial macaw
nests, and the hand-rearing of macaw chicks in captivity for later reintroduction into
the wild. The increasing level of human contact with the ecology of macaw species in
Tambopata, Peru has raised some concerns about how beneficial artificial breeding
and rearing strategies are to the overall conservation of macaws. In this paper, the
negative and positive effects of artificial strategies of macaw conservation taking
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place in the Tambopata Research Center are analyzed in order to assess whether
increased human care for the macaws in this region of the Peruvian Amazon.
Background:
There are six total genera of macaw: Anodorhynchus, Cyanopsitta, Ara,
Orthopsittaca, Primolius, and Diopsittaca, all of which are native to Central and South
America, parts of Southeastern Mexico, and formerly the Caribbean. Their relatively
large size, long protruding tails, and beautiful vivid-colored plumage mark these
spectacular members of the Psittaciforme (parrot) family. The Neotropical genus
Ara contains the highest number of species, ten, two of which have already gone
extinct. Macaws stand at a high risk of extinction mostly due to both aspects of their
own ecology, including high selectivity for nesting habitat and low reproductive
rate, and anthropogenic influences, namely destruction of habitat by deforestation
and the illegal pet trade.
The intricate designs of
the macaws distinguish them
from the rest of their parrot
family. Both their colorful
feathers and distinctive facial
patch are said to be as unique
as a fingerprint. However,
these differences are so subtle
that two macaws are virtually
A scarlet macaw perches itself on a bed in one of the TRC rooms.
Photo by: Robert Chun
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indistinguishable from one another. The size range for Macaws varies from the
smallest species, the Red-shouldered Macaw, or Hahn’s Macaw (Diopsittaca nobilis),
of 30-35 cm in length, to the largest, the Scarlet Macaw (Ara Macao), of 81-96 cm in
length. More than half of a macaw’s length is attributable to its long, graduated tail,
which, along with its impressive wingspan, makes it an apt, agile flyer with the
ability to reach speeds up to 56 kilometers per hour. Macaws have zygodactylous
feet, with two toes pointing forward and two pointing backward, which, functioning
like hands, allow them to easily grasp food and bring items to their mouths, as well
as sturdily perch onto and walk about tree branches.
Unlike most large birds, macaws are not birds of prey, but rather generalist
herbivores (Gilardi, 2012). Other than a trace amount of snails and insects, their diet
consists mainly of fruits, berries, palm stems, flowers, nectar, foliage and nuts found
in their rainforest environment. Their powerful angular beaks, with estimated bite
strength up to about 500-700 psi, support the macaw’s diet, allowing them to break
open even the toughest Brazil nut shells with ease. Their dry, scaly tongues actually
contain a small bone that allows it to function almost as a tiny finger, a useful tool
for licking off morsels of food into their beaks. As a way of decreasing dietary
competition, macaws tend to forage on unripe fruits and tough nuts that are too
difficult for most other creatures in their habitat to eat.
In the lowlands of the Peruvian Amazon (the focus for this paper), many of
the under-ripe fruits and nuts present in macaw diet contain toxins and other
caustic materials that plants have adapted as physical and chemical defense
mechanisms. The ability to digest these toxic fruits allows the macaws to exploit an
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abundance of foods rich in nutrients, throughout both rainy and dry seasons
(Gilardi, 2012). While the macaws are able to digest these substances, they can
cause severe dietary issues if ingested in large quantities. As a way of neutralizing
these toxins, macaws eat sodium-rich clay off of riverbanks, also known as “collpas”
or “clay licks,” which neutralize these
toxins; the clay particles actually bind
together with the toxins, preventing
absorption of the toxins, which are
passed out with fecal matter
(Brightsmith, 2003). While the clay
from these macaws’ diets are rich in
antioxidants, the macaws seem to be
The Collpa Colorado clay lick near the TRC, where the macaws
congregate to eat the sodium-rich clay.
more drawn to clay with higher sodium
content rather than higher antioxidant content (Powell et al. 2009). These findings,
as well as evidence of macaws feeding on salt from salt mines, have lead to theories
of sodium craving in Macaw diet. Whether it is for antioxidants or satisfaction of a
salty appetite, macaws are driven to congregate at clay licks almost daily, with a
strong influence on weather conditions and breeding conditions (Brightsmith,
2004).
The Convention on International Trade in Endangered Species of Wild Fauna
and Flora (CITES) has listed 7 species of macaw on their Appendix II, which lists
species that aren’t necessarily threatened with extinction, but have a high risk of
becoming extinct unless trade is closely monitored. Appendix I, which lists species
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that are most critically endangered and threatened with extinction, contains 11
species of macaw, 3 of which (the Blue-headed macaw, the Red-fronted macaw, and
the Scarlet macaw) are endemic to the Tambopata region.
One of the main drivers of the dwindling populations of macaws is their
naturally low reproductive rate. Macaws are generally highly selective of their
nesting habitat, preferring deep, dry nest cavities on old growth trees that only
occur at abundances of about one per 12-20 hectares of rainforest habitat. This
selectivity for suitable habitat makes it difficult for macaws to nest and fledge
young. Even when the macaws do nest, usually only a small fraction of their eggs
survive, due to predation of the eggs by jays, crows, and toucans. Even if eggs
survive to hatching, the parents will often only care for and feed one or two of these
eggs (usually the strongest of the fledglings), leaving the smallest to die of
malnutrition.
While the naturally low reproductive rate puts macaw populations at a
disadvantage, the largest drivers of their endangerment are anthropogenic: namely
the destruction of habitat and exploitation for the pet trade. With agricultural slash
and burn, urbanization, and projects like the Southern Interoceanic Highway, Peru’s
deforestation rate has increased significantly from 0.14 percent in 2005 to 0.22
percent in recent years. The Interoceanic Highway, which was completed in July
2011, cuts across the Tambopata reserve and has destroyed a great deal of
ecosystem and biodiversity in this region. In addition to projects like these, selective
logging in the Peruvian Amazon often targets the scarce old growth trees that
macaws rely on for nesting.
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While CITES lists the vast majority of macaw species as illegal to trade, lack
of enforcement of these regulations has led to the proliferation of trade of
endangered species. In Bolivia, a powerhouse in the South American bird trade, a
monitoring of the parrot pet trade from August 2004 to July 2005 found that 94% of
parrot individuals were believed to have been caught in the wild and several species
present in the trade were listed as endangered, such as the Hyacinth Macaw, the
Blue and Yellow Macaw, and the Scarlet Macaw (Hennessey and Herrera, 2007).
This study, which shows the high level of illegal parrot trade in Bolivia, suggests that
this is probably true for Peru and other receiving markets of the trade, such as
Brazil. In the illegal smuggling of illegally traded macaws, 90% of macaws do not
survive because of hazardous conditions of transportation. The going rate for a rare
species of macaw can be as high as $50,000 in the illegal trade market. One estimate
by the United Nationals Environment Programme priced the annual illegal
contribution of the pet trade in between $5—8 billion. (Oldfield, 2002, page 13).
These high prices provide large incentives for illegal traders, especially when
penalties are minimal to non-existent.
These threats to macaw populations led Eduardo Nycander to start the
Tambopata Macaw Project in 1989, with the aims of gathering data on the ecology
and natural history of macaws in order for conservation applications. The project is
located on the Tambopata River at the center of a large reserve site in the Madre de
Dios Region in Peru, surrounded by acres of pristine rainforest. This project led to
the construction of the Tambopata Research Center in order to house the project’s
research team. As Nycander began to concentrate on establishing the ecotourism
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company Rainforest Expeditions, as a way of ensuring funding for the Tambopata
Research Center, he passed on leadership of the project to Donald Brightsmith of
Texas A&M University.
Since his acceptance of the TMP torch, Brightsmith has taken the level of
macaw research to new heights, publishing countless works on his team’s firsthand
observations of macaw behavior, physiology, breeding habits, and phylogeny. The
location of the Project in the Peruvian Amazonian basin is ideal for macaw research,
with the largest known macaw clay lick, the “Collpa Colorado,” just down the river
from the TRC’s port. The research done at this frequently visited clay lick has led to
newfound information for over 15 different species of macaws. In addition, several
different macaw breeding projects
have been implemented in order to
bring up the dwindling population
numbers. The new focus for the
project under Brightsmith is aimed
at providing opportunities for
satellite projects in other South
American countries to spread the
conservation efforts of the TMP to
other areas of threatened macaw
habitat.
Some of the breeding
Two of the scarlet macaw "Chicos" greet an eager TRC visitor.
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strategies that the TRC has inaugurated include various breeding and rearing
strategies to introduce increase numbers of macaws into the wild, as well as the
construction of artificial nesting sites to promote natural breeding. In 1991,
Nycander led a project in which 30 macaws were hand-raised and released at TRC;
these “chicos,” as the TMP team knows them now, still make frequent visits to the
TRC. The artificial nesting strategies range from cutting the tops of palm trees in
order to promote natural decay for cavity (nesting) formation, to altered PVC pipes
being hung from trees. The effectiveness of these different nesting and breeding
techniques will be the focus of this paper.
Hypotheses:
While the aims of the Tambopata Macaw Project are at benefiting the
populations of macaws, the more hands-on strategies they have implemented have,
to an extent, broken the barrier that has existed between man and macaw. From
hatching to habitation, the nature of macaws of this region has been altered by the
TMP’s researchers, which draws in the risk of natural ecological disruption and
human dependency. Such concerns have led to the two hypotheses of this project:
1. The strategies for macaw nest construction that better mimic the natural
ecology of the species are more beneficial to the conservation of the species
than more artificial approaches.
2. Artificial breeding is less successful than natural breeding because it
interferes with the chicks’ ability to develop familiarity and behavioral
adaptations to their natural environment, establishing a dependency on
human care for their survival.
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Findings:
Nesting Strategies:
The first successful artificial nest boxes were created at the TRC in 1990. The
nest boxes were made from Ireartea palm trunks and were inhabited by wild
macaws. This resulted in the scarlet macaw (Ara Macoa) being the first species to
fledge young one of the nest boxes. However, these nest boxes were not sustainable,
in that they rotted away in less than two nesting seasons. A new nest box made
from cedar wood was tested in 1992, and proved to last longer than the palm trunk
nest boxes, but still rotted away very quickly (Brightsmith, 2000).
This led Eduardo Nycander to design the first PVC nest box in hopes to be
both successful and durable for macaw breeding. The boxes had tropical cedar tops
and bottoms to more closely mimic the natural tree nests. The results showed that
out of five nesting boxes, scarlet macaws used four in the 1992-1993 nesting season.
In 1999, the nest box designs were refined, replacing the wooden tops and bottoms
(which rotted away) with metal disks. That year 12 boxes were set up for scarlet
macaw habitation, nine of which were used for nesting. Based on the success of
these boxes, plans began for new artificial nest boxes specially designed for
habitation by other species of macaw and durability in their natural habitats.
(Brightsmith, 2000).
In 2006, Donald Brightsmith conducted an experiment in which artificial PVC
nest boxes were hung in live palm trees in order to increase the nesting sites for
blue-and-yellow macaws. The nest boxes were hung in the palm swamps near the
research center, where blue-and-yellow macaws naturally nested. The palms of this
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area, Mauritia flexuosa, have been known to be significant nesting resources for
macaws for both the abundance of fruit it produces and the cavity it forms when the
palm dies. The PVC pipes were left opened at the top to mimic the naturally
occurring cavities of the palms, themselves. The habitation of these artificial nest
boxes was then compared to the
habitation of natural nests in that area.
Their results showed that blue-andyellow macaws did not use any of the
artificial PVC nest boxes in the swamp
and the birds were not seen entering the
PVC nest boxes. Less than ten miles away,
33 blue-and-yellow macaw nests were
observed in dead M. flexuosa palms.
One of the wooden design nest boxes at the TRC.
photo by: Marika Jaeger
Brightsmith suggestes that “thermal characteristics, shape, drainage, or other basic
characteristics of the PVC nests were unacceptable to the blue-and-yellow macaws”
(Brightsmith, 2006).
In the same study, another attempt to promote blue-and-yellow macaw
nesting was conducted in which the tops of the M. flexuosa palms were cut off,
leaving the palm to slowly rot away, more accurately mimicking the natural nesting
habitat of the macaws. 12 blue-and-yellow macaws made nesting attempts in these
cut palms. In one nest, the bottom of the nest collapsed, destroying the eggs that
were there. In another, a chick hatched from an egg, but was depredated and did not
survive. In six nests, one chick fledged and survived. Four other nests were habited
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by macaw pairs, but did not fledge any chicks. While the cut palms seemed to
provide a better nesting habitat for blue-and-yellow macaws than the PVC nest
boxes, the palms had an average lifespan of about four years, after which time the
palms would fall over. In swamps with naturally dead palms, this is also the case,
but 1% of the palms in these swamps die per year, so as dead palms fall every four
years, more palms die, producing new suitable nesting sites. Brightsmith concluded
that in order for such a managed swamp to be successful, a 100-year rotation cycle
would have to be implemented, in which palms are cut and regrown (Brightsmith
2006).
Data from hundreds of blue-and-gold, red-and-green, and scarlet macaw
nesting observations was collected by the TRC to compare the effectiveness of
natural, PVC, and wooden nest structures. These results showed that Natural nests
had a 65% success (hatching of chicks) rate, while the PVC nest boxes only had a
success rate of 41%. The wooden nest boxes were not inhabited by enough macaws
to draw significant conclusions (Brightsmith, 2003).
Artificial Rearing Strategies:
In 1994, in order to gain a better understanding of the comparative health of
captive macaws and wild macaws, a health survey of parent- and hand-reared
scarlet macaws was conducted in the Tambopata-Candamo Reserve Zone in
Southwestern Peru. The physical examination for the birds consisted of blood
samples being analyzed for diseases. The results of this examination showed that
the hand-reared macaws were more susceptible to Salmonella. Those that tested
positive for Salmonella were known to have visited the TRC on a frequent basis. The
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birds were suggested to have contracted Salmonella in the kitchen of the lodge,
where chickens have been known to have been brought on multiple occasions
(Karesh, 1997).
In 2005, a collaborative study was done by Donald Brightsmith et al. on the
use of hand-raised scarlet macaws for reintroduction in Peru and Costa Rica. In this
study, 20 younger chicks were removed from natural and artificial nests in
Tambopata at age 5-15 days. Many of these chicks were from nests with 2-3 chicks,
and would not have survived naturally due to malnutrition associated with
preferential parenting. The chicks were taken and incubated at the TRC, after which
they were hand-raised in small boxes. No effort was made to isolate these chicks
from human contact. As the birds grew, little to no pre-release training for the
chicks occurred. The birds were not held in cages, so releases happened naturally, as
individual fledging birds flew into the forest 80-100 days after initial removal from
the wilderness. The birds returned to the lodge to be fed within a range of 12 hours
to 3 days.
Of the 20 macaws that were released, 74% survived their first year. Of that
74%, 96% survived the next year. As of March 2002, 55% of the original handreared individuals were still alive, even despite the threat of 5 known raptor species
that widely predate this area. The naïve birds were assumed to have learned both
feeding and survival techniques from the surrounding wild populations. The
released birds showed no fear for humans, and even returned regularly to the TRC
for food. At the TRC, the supplemental feeding actually promoted social interactions
among the flock members. This establishment of flock cohesion helped the released
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birds effectively alarm call at the sight of predators and return to the lodge for
safety.
Conclusions:
After further research and comparative analysis of the results, the original
hypothesis that “the strategies for macaw nest construction that better mimic the
natural ecology of the species are more beneficial to the conservation of the species
than more artificial approaches” has been found to have been plausible and
supported. As shown by the data, macaws have been observed to prefer their
natural nests over artificial nests, often times leaving artificial nests uninhabited.
Historically, artificial nests made from palm trunks and decapitated Mauritia
flexuosa palms have had better success in terms of macaw habitation and
reproduction than the more artificial PVC and wooden nest boxes.
However, even though these more natural nests were preferred (thus
habited) by the macaws, they were definitely not as durable or sustainable as the
more artificial PVC nest boxes. Therefore, it is arguable that if the PVC boxes were
somehow made to be more favorable to the macaws, they would be more beneficial
to macaw conservation, since they would be more sustainable than the natural
nests.
In addition, the second hypothesis that “artificial breeding is less successful
than natural breeding because it interferes with the chicks’ ability to develop
familiarity and behavioral adaptations to their natural environment, establishing a
dependency on human care for their survival” has been refuted by further research.
In actuality, artificial hand-rearing can actually allow for a higher survival rate of
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total chicks from one nest, especially in cases of nests with multiple eggs, since on
average only one chick would receive proper nutrition from parents, leaving the
others to die of malnutrition. However, increased human contact also increases the
risk of exposure to diseases like salmonella, which necessitates more controlled
rearing practices.
As exemplified by the “chicos” of the TRC, hand-reared chicks can survive to
fledging age and be reintroduced into the wild. Although these hand-reared macaws
do return to the lodge for an easy meal, they are able to survive in the surrounding
wilderness on their own, probably learning from other wild members of their
species essential survival techniques. In addition, supplemental human contact after
reintroduction of the macaws can actually promote social behavior, which in tern
promotes flock cohesion, mating, and protection from predation. However, one
might argue that these results might be different if the area of study was not
protected from poaching and pet trade, as is the case in the vast majority of nonreserve macaw habitat. Such threats urge wariness for the degree to which exposure
to human contact is helpful to macaw conservation in different settings.
Acknowledgments:
This study would not have been possible without the Sophomore College
Program, particularly the course: Conservation and Development Dilemmas in the
Amazon. I would like to thank Professor Bill Durham and Professor Julia NovyHildesley especially for organizing this course and teaching us so much about the
ecology, resilience, policies and indigenous cultures at the heart of the dilemma
surrounding the Amazon. I would also like to thank Rainforest Expeditions for their
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wonderful hospitality and for providing our group with a phenomenal set of
informative guides. A special thanks also to John Sutherland and Karen Alderete for
their great attention to detail in all aspects of this course’s logistics. Additionally, I
would like to thank Marika Jaeger and Robert Chun for their photographs that
appear in this paper. Lastly, I would like to thank all of the students and alumni who
participated in this course, whose vivacious and exploratory personalities made this
experience incredible on so many levels.
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