A typical community of local inland alog of Cuieiras River

Amazon forest is suffering great pressure of exploitation since the last century, either by the unordered wood exploitation, hunting and fishing. The lumber extraction and the effort of hunting are more intense along the river course. Cuieiras River is one of these examples. Along this river, many local communities (caboclo) use the river and the forest as subsistence source. The communities are more numerous between the medium course to until the estuary of the river, where the environment disturbance is more intense (Picture 1). In fact, the aboriginal groups and caboclos has been always depended on the hunting and fish as main source of food (Gross 1975, Ayres et al. 1979).

However, the constant presence of hunters in areas relatively little inhabited, such as the part between the medium and high Cuieiras (Picture 2) indicates that the caboclos are not hunting only for subsistence (Picture 3).

Picture 2 - "Cabloco" treating the hunt of the night before. See two pacas in the first plan. But, there is an increase in efforts for hunting due to a demand of wild animal's meat in urban centers as for restaurants or by ordered hunting. This means that, the intermediate pays for each hunted animal, either for weight of meat, or daily hunt or food. Although animal less common as the tapir, deer and monkeys (e.g. guariba/red howler monkey and macaco-aranha/black spider monkey) are hunted, the agoutis and coati are between the most easily found (Picture 3). The lack of social assistance programs and use of the land from the government part, this activity is even more difficult of being controlled. Therefore, the regional IBAMA does not have features and staff to inspect a large area. This situation can be still worst as IBAMA authorities announced the intention to extinguish 13 agencies of inspection in the state (J. Leland, "A Crítica" September 2 2000).

The partial view of high Cuieiras River.

On the other hand, the ecotourism can be an alternative. It associates economical interests and environmental protection. In the Kenya, for example, this type of tourism is one of the most lucrative activity of the country (EMBRATUR 1994). The worldwide level, is a market in expansion, grew about 60% in the last decade (EMBRATUR 1994). Considering the aperture of new jungle lodges in the neighborhoods of Manaus, already it is possible to foresee that this market also is in expansion in the region.

Part of Cuieiras Basin is already being used for the industry of ecotourism. However, it did not have any previous study of social or environmental impacts in the place. If well structured, for sure we will be able to search alternatives to involve the communities of caboclos, and thus generating direct and indirect jobs. Doing so, we could diminish the nature exploitation pressure exerted by them in the environment and to collaborate with conservation programs.

So far, it is necessary to know better the composition and abundance of the species of the flora and fauna to evaluate the impact of human being pressure is causing in the structures of the region. Therefore, few studies have been developed until the moment. For example, the vegetation studies are often directed to the arbor species of upland - Terra Firme (Jardim & Hosokawa 1986/87, Higuchi et al. 1998). Although a little is known about the composition of the flooded forest (igapó) of the region, it is possible that there is great similarity of the species already described for the same environment in Negro River region(Keel & Prance 1979, Pires & Prance 1985, Ferreira 1997). Regarding to fauna, some research have been developed in Terra Firme forest to the west of Cuieiras Basin (Biological Dynamic of Fragmented Forest project, PDBFF/INPA), including primates (Rylands & Keuroghlian 1988) and small and medium mammals (Emmons 1984, Malcolm 1990, 1997). Many of these animals also must occur in Cuieiras Basin. But, fauna of primates in the areas of forest along the Cuieiras River is a little diverse (8 species) than the areas of the PDBFF (6). It is possible that saiuim-de-coleira/pied tamarin (Saguinus bicolor), an endanger specie (IUCN 1995), can be one of these species. Therefore, if we get a bigger set of information, it will be possible to establish plans for the use of the land and conservation for the area in question.


Cuieiras River.The main objective is to make a preliminary evaluation of the present fauna in the region of high Cuieiras River, with emphasis in primates. This group was chosen because of great interest of ecologists, and can be good indicator of environment disturbance. Another factor that can attract the conservationists attention is the presence of endangers species, like saiuim-de-coleira/pied tamarin (Saguinus bicolor). Despite the high Cuieiras River being next to the border line of its distribution, their presence was still not proven because of lack of surveys in that place.

Focused Area

The study was developed in the high Cuieiras River between the limits of ZF2 branch road(S 02 33 W 060 19) which connects BR174 to the Cuieiras riverbank, and about 5 km above the confluence with Branquinho River (31 S 02 W 060 16). (Picture 4 is a very large satellite picture to let available in the Internet).

The local topography is soft with moderate declivitous. The soil is latosol (Ferralsol/Oxisol) type; yellow argillaceous ground and generally poor in mineral nutrients (Sombroeck 1984). The annual totals of precipitation varying within 1355 mm to 2840 mm (Higuchi et al. 1998). The annual river level fluctuation in the region is about 14 m. The period between high waters (December-July) and low (August-January) varies from 50 to 270 days (Ferreira 1997). The vegetation is flooding forest (mata de igapó) and Terra Firme forest (Pires & Prance 1985). The leguminosaes are the species most common along the riverbank and small creeks (igarapés) in igapó forest of the Negro River region. Individually, latifolia Aldina (Leguminosae) and oblongifolia Amanoa (Euphorbiaceae) are most numerous (Ferreira 1997), but Couratari tenycarpa is particularly abundant in areas constantly flooded (P. Apóstolo, personal communication). The non-flooded forest is dense type of Amazonian Terra Firme (Pires & Prance 1985). This type of vegetation is quite heterogeneous, where the most important families are Lecythidaceae, Sapotaceae, Euphorbiaceae, Caesalpinaceae, Moraceae and Mimosaceae (Jardim & Hosokawa 1986/87, Rankin-of-Merona et al. 1992). The vegetal species are distributed on three main habitats: plateau, slope and sandbank. In plateau, the most important trees are the castanha de macaco (Cariniana micrantha, Lecythidaceae), marupá (Simaruba amara, Simarubaceae), cumarurana ( Dipteryx magnifica , Fabaceae), muirapiranga (Eperua bijuga), violeta (Peltogyne catingae, Caesalpinaceae), rosada brava (Micropholis williami, Sapotaceae), angelim pedra ( Dinizia excelsa , Mimosaceae), castanha jarana (Lecythis retusa, Lecythidaceae) and caroba (Jacaranda copaia, Bignoniaceae). In the slope, rosada brava (Micropholis williami, Sapotaceae) one, carapanaúba (Aspidospermum oblogum, Apocynaceae), cupiúba (Goupia glabra, Celastraceae), macucu murici (Vantanea sp., Humiriaceae), periquiteira ( Cochlospermum orinoccense , Bixaceae), violeta (Peltogyne catingae, Caesalpinaceae) and macucu (Licania micrantha, Chrysobalanaceae). In the sandbank, we again found rosada brava ( Micropholis williami , Sapotaceae) and others such as dima ( Croton lanjouwensis , Euphorbiaceae) and castanha de cotia ( Ptychopetalum sp., Olacaceae) (Higuchi et al. 1998), matá-matá ( Eschweilera odora , Lecythidaceae), abiurana (Micropholis sp., Sapotaceae), ripeiro vermelho (Corythophora high, Lecythidaceae), seringarana (Micranda rossiana, Euphorbiaceae) and muirapiranga (Eperua bijuga, Caesalpiniaceae) (Higuchi et al. 1998).


The primate census followed the method of linear observation throughout one transect (NRC 1981). This method considers one transect with a predetermined length, where its width can be calculated considering the distance observer-animal or animal-transect. In this study the width considered for the transect was 60 m (30 m each side), thus the density was calculated by the following formula:

Density = Total number of individuals found / total of covered area (resulted in km2).

The methodology of transect consists of observer walking, using a binoculars, in a constant speed of 1-1,5 km/hour and with stops each 50 m. The stops allow the observer to perceive sounds and movements of the animals and, thus, improving the census efficiency. Each time that an animal or group was observed, it had been registered the following information: time, habitat where the animal was found, species, number of individuals, mode of detection (visual, movement, vocalization, smell and excrement), animal-observer distance, perpendicular distance between the animal and transect, height where the animal was seen, age group and type of food source used (facultative). Three types of environments had been showed during the censuses: (1) border of igapó forest (river margin), (2) igapó and transition forest and (3) high Terra Firme forest. The environment of igapó border was covered using a canoe (motor 15 HP) at a constant speed of 4 km/hour (transect of 5 km between the limit of the ZF2 and Cuieiras river above the confluence of Branquinho River). In the other environments, it was used two tracks with extension of 3 km each. In parallel, we registered all the individuals that had been observed outside of the track or after the censuses had been concluded. Other means of detection also had been used (vocalization, excrements, etc.). Although this study was centered in primate, we registered all the other groups found during the censuses.


The censuses was developed during the dry station between the months of September and October 2000. The data were collected during three excursions, in total of 10 days in the field. The covered distance was not uniform between the three environments: (1) high Terra Firme, 15 km; (2) igapó and transition forest, 6 km; and (3) constantly flooded forest (river margin), 18 km. The census registered four of the seven or eight species of primates, which occur in the area: macaco-aranha/black spider monkey ( Ateles paniscus ), cuxiú/bearded sakis (Chiropotes satanas), macaco-prego/brown capuchin monkey (Cebus apella) and macaco-de-cheiro/squirrel monkey (Saimiri sciureus). Guariba/Red howler monkey (Alouatta seniculus) was observed only once during occasional tracks. But, the parauacú/white-faced saki monkey (Pithecia pithecia), saiuim-de-coleira/pied tamarin (Saguinus bicolor) and sauim-da-mão-douro/red-handed tamarin (Saguinus midas) had not been registered. One of the reasons was the low survey effort made (only six days of census), and therefore the estimate of primate density was mentioned only for comparative effect. Any way, some regional data was also included to present general trend for the Central Amazon (Table 1). The macaco-de-cheiro/squirrel monkey, a fruit-insectivore behavior, occurs predominantly in igapó and transition forest, and everything indicates that it is the species most abundant in these areas. The cuxiú/bearded saki also was only observed once using igapó forest (consuming seeds of Couratari tenycarpa, Lecythidaceae). This plant is quite common in the edges of the rivers. However, they had not been registered in the edge of Terra firme forest, as well as the brown capuchin monkey; perhaps because the great availability of sources in the igapó forest during this time of the year.

Although this study was centered in primate, in parallel we registered other groups of animals during the censuses. The data had relieved the existence of species that indicate of environment with lesser degree of disturbance, such as:

> Birds: gavião-real/harpy eagle (Harpia harpyja), mutum/black curassow ( Crax alector ), jacú/guan (Penelope sp.), jacamim/trumpeter (Psophia viridis), inhambu-galinha/tinamou (Tinamussp.), tucanos/toucans (Ramphastos tucanus) and araras (scarlet macaw/Ara macao and blue-and-yellow macaw/A. ararauna).

> Mammals: anta/tapir ( Tapirus terrestris ), veado/deer (American Mazama), catetú/peccary (Pecari tajacu), ariranha/giant river otter(Pteromura brasiliensis), paca/agouati (Agouti paca) and cotia (Dasyprocta leporina).

Table 1. Density of primate in three different types of habitats of high Cuieiras river. The regional density found for some species in Terra Firme forest was also included, as well as occasional comments and other means of detention that prove the presence of the species in the place.

Habitat Species Density ( -2) Regional Density* ( Including all the means of detection **
Terra FirmeAteles paniscus 1.41.0YES
Alouatta seniculus -10.5YES
Chiropotes satanas -5.5-
Pithecia Pithecia -0.7-
Cebus apella -2.2-
Saguinus midas -3.9-
Bicolored Saguinus ---
Igapó andAteles paniscus ---
Transition ForestAlouatta seniculus --YES
Chiropotes satanas --YES
Pithecia Pithecia ---
Cebus apella 30-YES
Saimiri sciureus 60-YES
Saguinus midas ---
Bicolored Saguinus ---
RiverbankAteles paniscus ---
Alouatta seniculus ---
Chiropotes satanas 4,6-YES
Pithecia Pithecia ---
Cebus apella ---
Saimiri sciureus --YES
Saguinus midas ---
Bicolored Saguinus ---

* Rylands & Keuroghlian 1988
** Occasional Censuses, comments, vocalization and excrements

Beyond the fauna, the local forest also contains arboreas species that indicate minor exploitation pressure, such as: cardeiro (Scleronema micrantha), acariquara (Minquartia guianensis), amapá ( Brosimum parinarioides ), tanimbuca (Buchenavia parvifolia), angelim-pedra (Dinizia excelsa) and cajuí (Anacardium occidentale).


The sauim-de-coleira/pied tamarin, a species threatened of extinguishing (IUCN 1995), has its distribution area geographic located to the neighborhoods of Manaus (Hershkovitz 1977, Ayres et al . 1980). Although the Basin of the Cuieiras probably is inside of the area of its distribution, it was not registered any during the censuses. But does it occur in the study place? The local inhabitants believe that this sauim-de-coleira/tamarin occurs in the neighborhoods. However, it is most probably that the sauim-da-mão-douro ( Saguinus midas ) appears in more abundance in that place. The transition area between those two species seems to be at the ebb tide of the river (S. Egler, not published). However, Egler still did not finish all the surveys considered for the region. It is possible that intensive surveys, including all the area of the Basin, can clarify this question in the future.

Although that the majority of the species foreseen for the area had been detected, few of them had been registered during the censuses, mainly in areas of Terra firme land forest. One of the reasons was the low survey effort and, probably, for being a period of low availability of fruits in those forests. Therefore, the joined data of density must be seen with certain caution. In any way, a bigger number record was expected during the censuses, mainly of the more abundant species, as guaribas/red howler monkey. Therefore, even so the results are preliminary, already it is possible to indicate that a pressure of human being exists in the populations of primate in the region. In fact, the animals such as guariba/red howler monkey, macaco-aranha/black spider monkey, anta/tapir and veado/deer are the main target of the hunters in Amazon region (Smith 1976, Redford & Robinson 1987, Peres 1990). The results of the census and the constant meeting with hunters strengthen these data. In contrast, species of lesser interest, like macaco-de-cheiro/squirrel monkey, still seems to be abundant in the region. As well as, in other places of its distribution (Klein & Klein 1975, Terborgh 1983, Robinson & Janson 1987).

The hunting pressure seems to be more intense in the edge areas of water courses. For example, there was only one register of guariba/red howler monkey (not computed during the census) in the band between river and 3 km in the inward of the forest. However, all the five vocalizations of guaribas had been heard beyond this band. In fact, there is no alternative by land that facilitates the access to the distant areas, therefore the INPA (National Institute of Research of the Amazon Region) controls the people access who uses ZF2 road; a branch BR 174 speedway.

There was an expansion of the human being occupation in the surrounded areas with the tarring of BR 174, as well as in its branches ones (Fig. 5). This unordered occupation is causing an increase in the destruction of the forest, and facilitating to the access the before remote areas (Laurance & Vasconcelos 2000), as the region of the high Cuieiras river. So, more awareness and bigger vigilance in the riverbank regions would become possible to protect a greater area of forests as part of it already protected by the INPA projects.

Concluding, despite the exploitation of natural resources pressure in the area in question, the data had revealed that species of the flora and fauna indicating environments with lesser degree of disturbance exist. Therefore, it is still possible to consider it as an ecological shelter. But, what can we do to preserve it or for little preventing a bigger environment disturbance? Unhappily, there are no plans in short term to solve this question. It is possible that the ecotourism will be one of the alternatives to associate conservation with economic interests. Since, the local population is involved. So, studies of social, economic and environment impact must be considered before any action.


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Wilson Robert Spironello
Instituto Nacional de Pesquisa do Amazonas (INPA)


Conservation International (US)


Ademir Costa de Oliveira (INPA)

Jose Eremildes de Souza Gomes (Field Assistant)

Pablo Apostolo Costa Lima Installation (Field Assistant)

Ricardo Daniel Pedroso (Viverde Turismo)
Manaus - November 2000