Cocha Cashu Biological Station
Encyclopedia
Cocha Cashu Biological Station (Estación Biológica Cocha Cashu or EBCC) is a tropical
biological research station
located at 11° 54'S and 71° 22'W in Manú National Park
, Peru
. It was established in 1969-70, predating the founding of its containing national park (est. 1973). Though only 10 km2 in area, the site has provided valuable research. The station is situated on the shore of an oxbow lake
, from which it takes its name. "Cocha" is the Quechua
word for lake. "Cashu" is derived from the English word "cashew
" and refers to the shape of the lake.
Those areas which lie outside the path of the Rio Manu's meandering edges have vegetation much older than those closer to the river, but due to common treefall, the forest canopy is low. Much of the forest is only 25-30 meters tall, with a number of trees extending outside this range at 50 meters tall or more. An extensive network of lianas
extends across the understory. Patches of bamboo, totaling almost a third of the locality, are marked by a scarcity of trees.
and Barro Colorado Island
(BCI) managed by the Smithsonian Tropical Research Institute
(STRI) in Panama
, Cocha Cashu is one of the best-studied ecological sites in the tropics
. However, unlike La Selva or BCI, Cocha Cashu is in an area minimally impacted by humans, surrounded by millions of hectares of virgin forest
, and thus provides critical insights into the organisms and processes found in a healthy, natural tropical rainforest
. Over 500 articles, books, and other publications have resulted from field research conducted at Cocha Cashu.
Studies related to those done at Cocha Cashu has been conducted at nearby Pakitza (link), on the same bank of Rio Manu, 21 km ESE. The two areas are very similar in makeup, reside at nearly the same elevation, and are not disconnected to impede species movement.
. It is thought that this inequality may be due to either lack of intensive collection of these smaller flora, or due to scarce precipitation outside of the rainy season.
Leguminosae
(legumes) is the outstanding family of flora species makeup, with over 90 species. Moraceae
, Rubiaceae
, and Pteridophyta follow, with over 50 documented species each. Although no particular species of flora found at the Manu site was considered endemic to the area in 1990, it was suggested that the rate of forest loss might soon have created endemism.
Annual production of seeds and fruit is high and well supports the site's animal communities. It has been considered that this may be in some significant part due to the prevalence of strangler figs, which make up a high proportion of the taller trees embedded within the canopy.
Insectivorous species dominate overall with 163 species, though many of these appear in the understory. Birds with a near-exclusive fruit diet numbered 58, occurring most often in canopies along with omnivores.
Common species include hummingbirds, manakins, and trumpeters
.
thoroughly studied (as of 1990). It is thought, however, that the makeup herp communities might be very similar in Manu to that of other areas along the western Amazon Basin. Even with only the limited studies done on herpetofauna here, there appears to be a high diversity of species.
In 2008, a study was conducted on amphibians at nine sites near Madre de Dios
, one of these being Cocha Cashu. Results of this research found that 78 of the 114 species (68%) studied were found around the station, a nationally-recognized protected area, while only 7.9% of the species observed were found outside of protected areas. These results stress the importance of national protection to the conservation of species diversity.
, spider monkeys, woolly monkeys, and peccaries
, as these populations have been highly hunted elsewhere.
While fairly comprehensive lists of mammalian diversity at Cocha Cashu exist , most are over ten years old and may not be in line with current conditions. As of 1990, 70 nonflying mammal species had been recorded at the site, the majority of these being fruit-pulp eaters. Rodents were the most common category of mammals, with 24 species. Primates consisted of 13 species, carnivores of 12 species, and marsupials of 8 species. Together, these four groups made up over 80% of total identified species. Members of the felidae
family were found in surprising abundance, compared to other Neotropical sites.
The effect of tree gaps, an important factor in the study of tropical ecology, was studied at Cocha Cashu in reference to small mammals (rodents). No difference was found in the fruit feeding habits of either species studied between gap and understory areas, but were found to consume more fruit in the rainy season, when fruit was more abundant, than in the dry season.
Another paper based in the area proposes that these rodents are important assistants to the dispersal of mycorrhizal fungi, an important plant mutualist
partner, in lowland Peruvian wet forest. The discussion of this study suggests the results may be applied generally to Neotropical areas.
. Because it is within Manú National Park, the station is officially owned and regulated by INRENA, Peru's National Natural Resources Institute. The station has been operated by John Terborgh
, an environmental science
professor at Duke University
, since the early 1980s
. The nearest roads reach the towns of Shintuya and Atalaya, two days away by boat. Flights to Boca Manú still require a day-long boat ride up the Manú River to reach the station.
, anacondas, caimans, jaguars, pumas, peccaries
, electric eels, stingrays, numerous poisonous snakes, insects, scorpions, spiders, plants, and other dangers. However, researchers at the station have interacted closely with the plants and animals of the rainforest for decades with very few negative encounters.
One notable exception occurred on April 27, 2000, when Francis J. Bossuyt disappeared while bathing in the lake. He has never been found, and presumed dead, perhaps killed by a caiman. In the years since, a memorial in his name was established at the station, and more researchers and other visitors have chosen to use buckets or pumped water to bathe instead.
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
biological research station
Research station
A research station is a station built for the purpose of conducting scientific research. Research station sites might include outer space and oceans. Many nations have research stations in Antarctica; Showa Station, Halley and Troll are examples...
located at 11° 54'S and 71° 22'W in Manú National Park
Manú National Park
Manú National Park is a biosphere reserve located in Madre de Dios and Paucartambo, Cusco. Before becoming an area protected by the Peruvian government, the Manú National Park was conserved thanks to its inaccessibility. The park remains fairly inaccessible by road to this day. In 1977, UNESCO...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
. It was established in 1969-70, predating the founding of its containing national park (est. 1973). Though only 10 km2 in area, the site has provided valuable research. The station is situated on the shore of an oxbow lake
Oxbow lake
An oxbow lake is a U-shaped body of water formed when a wide meander from the main stem of a river is cut off to create a lake. This landform is called an oxbow lake for the distinctive curved shape, named after part of a yoke for oxen. In Australia, an oxbow lake is called a billabong, derived...
, from which it takes its name. "Cocha" is the Quechua
Quechua languages
Quechua is a Native South American language family and dialect cluster spoken primarily in the Andes of South America, derived from an original common ancestor language, Proto-Quechua. It is the most widely spoken language family of the indigenous peoples of the Americas, with a total of probably...
word for lake. "Cashu" is derived from the English word "cashew
Cashew
The cashew is a tree in the family Anacardiaceae. Its English name derives from the Portuguese name for the fruit of the cashew tree, caju, which in turn derives from the indigenous Tupi name, acajú. It is now widely grown in tropical climates for its cashew nuts and cashew apples.-Etymology:The...
" and refers to the shape of the lake.
Environmental Makeup
The area is geographically diverse, consisting of grasslands bordering the Andes, gorges, and plains where climate is more variant and drier. The oxbow lake itself contributes areas of marsh and brushland. This is a nutrient-rich site, the soil consisting of silt and sand, and turnover along the riverbank occurs generally within 1000 years. The annual rainfall average is somewhat over 2000 mm, most of this falling from November to May. A marked dry season is from June to August. These factors combined lend to a relatively rapidly-changing landscape.Those areas which lie outside the path of the Rio Manu's meandering edges have vegetation much older than those closer to the river, but due to common treefall, the forest canopy is low. Much of the forest is only 25-30 meters tall, with a number of trees extending outside this range at 50 meters tall or more. An extensive network of lianas
Liana
A liana is any of various long-stemmed, woody vines that are rooted in the soil at ground level and use trees, as well as other means of vertical support, to climb up to the canopy to get access to well-lit areas of the forest. Lianas are especially characteristic of tropical moist deciduous...
extends across the understory. Patches of bamboo, totaling almost a third of the locality, are marked by a scarcity of trees.
Research
Along with La Selva Biological Station in Costa RicaCosta Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
and Barro Colorado Island
Barro Colorado Island
Barro Colorado Island is located in the man-made Gatun Lake in the middle of the Panama Canal. The island was formed when the waters of the Chagres River were dammed to form the lake. When the waters rose, they covered a significant part of the existing rainforest, and the hilltops remained as...
(BCI) managed by the Smithsonian Tropical Research Institute
Smithsonian Tropical Research Institute
The Smithsonian Tropical Research Institute in Panama, the only bureau of the Smithsonian Institution based outside of the United States, is dedicated to understanding biological diversity. What began in 1923 as small field station on Barro Colorado Island in the Panama Canal Zone has developed...
(STRI) in Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
, Cocha Cashu is one of the best-studied ecological sites in the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
. However, unlike La Selva or BCI, Cocha Cashu is in an area minimally impacted by humans, surrounded by millions of hectares of virgin forest
Virgin Forest
Virgin Forest is a self-described B-movie starring Sarsi Emmanuel, who plays a barrio lass of Chinese ancestry; the late Miguel Rodriguez, as a Filipino-Spanish illustrado; and, Abel Jurado, who plays the lover of Sarsi's character.-Synopsis:...
, and thus provides critical insights into the organisms and processes found in a healthy, natural tropical rainforest
Tropical rainforest
A tropical rainforest is an ecosystem type that occurs roughly within the latitudes 28 degrees north or south of the equator . This ecosystem experiences high average temperatures and a significant amount of rainfall...
. Over 500 articles, books, and other publications have resulted from field research conducted at Cocha Cashu.
Studies related to those done at Cocha Cashu has been conducted at nearby Pakitza (link), on the same bank of Rio Manu, 21 km ESE. The two areas are very similar in makeup, reside at nearly the same elevation, and are not disconnected to impede species movement.
Flora
The Rio Manu area, in 1990, was found to consist of 1,856 species of vegetation, in comparison to the 2,874 species found in the entire national park. Much of the forest is dominated by trees and shrubs, rather than having a considerable population of epiphytes and terrestrial herbsHerb
Except in botanical usage, an herb is "any plant with leaves, seeds, or flowers used for flavoring, food, medicine, or perfume" or "a part of such a plant as used in cooking"...
. It is thought that this inequality may be due to either lack of intensive collection of these smaller flora, or due to scarce precipitation outside of the rainy season.
Leguminosae
Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...
(legumes) is the outstanding family of flora species makeup, with over 90 species. Moraceae
Moraceae
Moraceae — often called the mulberry family or fig family — are a family of flowering plants comprising about 40 genera and over 1000 species. Most are widespread in tropical and subtropical regions, less so in temperate climates...
, Rubiaceae
Rubiaceae
The Rubiaceae is a family of flowering plants, variously called the coffee family, madder family, or bedstraw family. The group contains many commonly known plants, including the economically important coffee , quinine , and gambier , and the horticulturally valuable madder , west indian jasmine ,...
, and Pteridophyta follow, with over 50 documented species each. Although no particular species of flora found at the Manu site was considered endemic to the area in 1990, it was suggested that the rate of forest loss might soon have created endemism.
Annual production of seeds and fruit is high and well supports the site's animal communities. It has been considered that this may be in some significant part due to the prevalence of strangler figs, which make up a high proportion of the taller trees embedded within the canopy.
Birds
While the uncovering of the bird community dynamics of this area of the Amazon lagged behind other Amazonian sections, Cocha Cashu is considered a center of avian endemism (as identified by Haffer in 1985). Mist-net sampling of the bird populations at the site began in 1973, and by 1990, data on 435 regularly-occurring species had been collected.Insectivorous species dominate overall with 163 species, though many of these appear in the understory. Birds with a near-exclusive fruit diet numbered 58, occurring most often in canopies along with omnivores.
Common species include hummingbirds, manakins, and trumpeters
Trumpeter (bird)
The trumpeters are a family of birds restricted to the humid forests of the Amazon and Guiana Shield in South America. They are named for the trumpeting or cackling threat call of the males. The three species resemble chickens in size; they measure 45 to 52 centimetres long and weigh 1 to 1.5...
.
Herps
Initial studies at Cocha Cashu centered around the black caiman (Melanosuchus niger), and thus this is the only species of herpetofaunaHerpetology
Herpetology is the branch of zoology concerned with the study of amphibians and reptiles...
thoroughly studied (as of 1990). It is thought, however, that the makeup herp communities might be very similar in Manu to that of other areas along the western Amazon Basin. Even with only the limited studies done on herpetofauna here, there appears to be a high diversity of species.
In 2008, a study was conducted on amphibians at nine sites near Madre de Dios
Madre de Dios Region
Madre de Dios is a region in southeastern Peru, bordering Brazil, Bolivia and the Peruvian regions of Puno, Cusco and Ucayali. Its capital is the city of Puerto Maldonado. The name of the region is a very common Spanish language designation for the Virgin Mary, literally meaning Mother of...
, one of these being Cocha Cashu. Results of this research found that 78 of the 114 species (68%) studied were found around the station, a nationally-recognized protected area, while only 7.9% of the species observed were found outside of protected areas. These results stress the importance of national protection to the conservation of species diversity.
Mammals
Cocha Cashu's large mammal communities, due to being within a protected park, have not felt the effects of hunting which have damaged other Neotropical communities. This makes Manu a good place to study how tropical species communities may have looked and functioned before the influx of humans and technology. This is particularly relevant when studying jaguars, tapirs, ocelots, capybaras, giant ottersGiant Otter
The giant otter is a South American carnivorous mammal. It is the longest member of the Mustelidae, or weasel family, a globally successful group of predators. Unusually for a mustelid, the giant otter is a social species, with family groups typically supporting three to eight members...
, spider monkeys, woolly monkeys, and peccaries
White-lipped Peccary
The White-lipped Peccary, Tayassu pecari, is a peccary species found in Central and South America, living in rainforest, dry forest and chaco scrub. It is monotypic within the genus Tayassu....
, as these populations have been highly hunted elsewhere.
While fairly comprehensive lists of mammalian diversity at Cocha Cashu exist , most are over ten years old and may not be in line with current conditions. As of 1990, 70 nonflying mammal species had been recorded at the site, the majority of these being fruit-pulp eaters. Rodents were the most common category of mammals, with 24 species. Primates consisted of 13 species, carnivores of 12 species, and marsupials of 8 species. Together, these four groups made up over 80% of total identified species. Members of the felidae
Felidae
Felidae is the biological family of the cats; a member of this family is called a felid. Felids are the strictest carnivores of the thirteen terrestrial families in the order Carnivora, although the three families of marine mammals comprising the superfamily pinnipedia are as carnivorous as the...
family were found in surprising abundance, compared to other Neotropical sites.
The effect of tree gaps, an important factor in the study of tropical ecology, was studied at Cocha Cashu in reference to small mammals (rodents). No difference was found in the fruit feeding habits of either species studied between gap and understory areas, but were found to consume more fruit in the rainy season, when fruit was more abundant, than in the dry season.
Another paper based in the area proposes that these rodents are important assistants to the dispersal of mycorrhizal fungi, an important plant mutualist
Mutualism
Mutualism is the way two organisms of different species biologically interact in a relationship in which each individual derives a fitness benefit . Similar interactions within a species are known as co-operation...
partner, in lowland Peruvian wet forest. The discussion of this study suggests the results may be applied generally to Neotropical areas.
Other Research
An intense storm event in 1994 in Cocha Cashu's locale prompted study of the effects of such storms on tropical forests. This particular event had been the most severe recorded within the 15 years prior. Wind knocked down 40 recorded trees, not counting those that had been felled by nearby treefall. These tended to be individuals that were emergent over the canopy, and the presence of root buttresses did not appear to affect whether the individual was susceptible to toppling due to these gusts.History
The Cocha Cashu Biological Station was established in the 1960s by German researchers studying black caimanBlack Caiman
The black caiman is a crocodilian. It is a carnivorous reptile that lives along slow-moving rivers and lakes, in the seasonally flooded savannas of the Amazon basin, and in other freshwater habitats in South America. Once common, it was hunted to near extinction primarily for its commercially...
. Because it is within Manú National Park, the station is officially owned and regulated by INRENA, Peru's National Natural Resources Institute. The station has been operated by John Terborgh
John Terborgh
John W. Terborgh is a conservation biologist.Terborgh graduated from Harvard College in 1958 and received his PhD in plant physiology from Harvard University in 1963....
, an environmental science
Environmental science
Environmental science is an interdisciplinary academic field that integrates physical and biological sciences, to the study of the environment, and the solution of environmental problems...
professor at Duke University
Duke University
Duke University is a private research university located in Durham, North Carolina, United States. Founded by Methodists and Quakers in the present day town of Trinity in 1838, the school moved to Durham in 1892. In 1924, tobacco industrialist James B...
, since the early 1980s
Facilities
The remote, rustic station consists of a few thatched roofed buildings clustered in two small clearings, and a network of trails into the forest. There are no dormitories or other forms of housing. All researchers, staff, and visitors must sleep in their own tents in the surrounding forest. Additionally, there are also no fixed plumbing systems. Toilets consist of a pair of pit latrines. Water for drinking, cooking, bathing, and washing clothes is pumped by hand from the lake.Access
Cocha Cashu is only accessible by boat or float planeSeaplane
A seaplane is a fixed-wing aircraft capable of taking off and landing on water. Seaplanes that can also take off and land on airfields are a subclass called amphibian aircraft...
. The nearest roads reach the towns of Shintuya and Atalaya, two days away by boat. Flights to Boca Manú still require a day-long boat ride up the Manú River to reach the station.
Dangers and Hazards
The many hazards of the Amazonian rainforest are well-publicized, including piranhasPiranhas
Piranhas is a historic city and municipality in the western of the State of Alagoas, in the Northeast Region of Brazil. Located on the bank of the São Francisco River, just at the border with the State of Sergipe, Piranhas was founded in 1891 and originally named Floriano Peixoto...
, anacondas, caimans, jaguars, pumas, peccaries
White-lipped Peccary
The White-lipped Peccary, Tayassu pecari, is a peccary species found in Central and South America, living in rainforest, dry forest and chaco scrub. It is monotypic within the genus Tayassu....
, electric eels, stingrays, numerous poisonous snakes, insects, scorpions, spiders, plants, and other dangers. However, researchers at the station have interacted closely with the plants and animals of the rainforest for decades with very few negative encounters.
One notable exception occurred on April 27, 2000, when Francis J. Bossuyt disappeared while bathing in the lake. He has never been found, and presumed dead, perhaps killed by a caiman. In the years since, a memorial in his name was established at the station, and more researchers and other visitors have chosen to use buckets or pumped water to bathe instead.