Background

1. Habitat

Kaburi Creek is located on the Corantyne river in West Suriname just north the Carib Indian settlement of Washabo (N 05°.15'. 586, W 057°.12'.782 ). It is a small black water creek that narrows to a few meters in width as it meanders along its winding 13 km east/southeasterly course, eventually disappearing into a densely vegetated swamp due south of Nanni Lake.

Due to its proximity to the equator, Suriname has a genuine tropical climate with high temperatures and humidity (82-95%) throughout the year. There are two rainy seasons: a long rainy season (April-July) and a short one (December-January). The amount of rain and its onset and duration can vary markedly from year to year.

Vegetation along the banks of small forest creeks such as Kaburi Creek can be divided into the following categories:

Riverbank high forest. The mesophytic rain forest grows to the creek's edge and tall Mora tropical hardwood trees (Mora excelsa) are seen. High banks guard the forest from seasonal flooding. Riverbank high forest is found in patches along the first 3 km of Kaburi Creek. Otters prefer lower lying areas with some undergrowth.

Mixed marsh and high swamp forest. Xerophytic floodable swamp forest is lower than riverbank high forest and is flooded during the rainy season to a depth of 2 m or more. Tall trees such as pencil-thin Pina palms (Euterpe oleracea), or hydrophytic trees such as babun trees (Virola surinamensis), and mataki trees (Symphonia globulifera) predominate as well as dense stands of thorny keskesmaka palms (Bactris maraja). The thick clay soil drains slowly and it is usually poor otter habitat.

Low marsh forest. Floodable swamp forest may be under water for most of the year. It is largely composed of thick vegetation and few small trees. In more open areas the Mauritius palm (Mauritia flexuosa) is seen, standing tall among the floating grass islands common in this habitat. The soil drains well when the ground is above water level and it is used by otters during the dry season.

Grass islands and floating meadows. Floating grass mats, usually composed of Ipomoea reptans are found in the more open areas of the creek. These are fishing spots highly favored by both the Indians and otters: Arawaboo Pond, Swallow Pond, Karekouya Pan, Monkey Pan. (see map)

Kaburi Creek is also characterized by high ground "islands" of marsh forest and high swamp forest that are dry year around or flooded only at the height of the rainy season. They are located at wide intervals along Kaburi Creek. Such areas are prized by both Indians and Giant otters (Pteronura brasiliensis) as dry season campsites (see below and Table 2).

2. Biodiversity

Centermost of the three Guianas, Suriname is under populated, by South American standards, and remains 85% uninhabited. The rainforests of central Suriname are a stronghold of endangered and rare species that have been extirpated in other regions of South America. The biodiversity of these areas is extraordinary and remains largely unstudied due to their remoteness.

Kaburi Creek, within easy reach of local Carib and Warrau Indian fishermen and hunters, has been exploited on a sustainable yield basis for centuries. Only the manatee (Trichechus manatus) was hunted to extinction in this creek some 40 years ago (James Lingaard, pers. comm., 1978). The manatee is said to still occur in Nanni creek and Nanni Lake just north of the creek.

Even though it is a relatively narrow black water creek in its upper reaches, above 14 km from the mouth, the variety of the successive habitats makes Kaburi Creek a rich environment for a wide variety of forest and swamp species. These species are seldom seen farther north in the coastal savannahs where the effects of agriculture, hunting and habitat loss have taken their toll. This mosaic of successive habitats promotes biodiversity, making the Kaburi Creek area particularly valuable for conservation purposes.

3.The Giant Otter

The species. The Giant otter one of the larger carnivores of South America, is a primarily terrestrial mustelid that has become extremely well adapted to using an aquatic environment. Adult males measure up to 1.8 m and weigh 26-32 kg. , females measure up to 1.7 m and weigh 22-26 kg. It lives in large, noisy family groups and shows little fear of humans.

Its status. Such a large, diurnal and gregarious animal makes an easy target for pelt hunters. Today it is the combined effects of habitat loss and the demands of the fur industry that are responsible for Pteronura's endangered status over much of its range in South America. In Suriname where the local populations have never hunted it, the Giant otter enjoys relative security, particularly in the more remote areas. For this reason, the first detailed study of Pteronura in the wild was made in Suriname in 1976-1978, much of it in Kaburi Creek (Duplaix, 1980).

Habitat selection and seasonal requirements. Like many carnivores, Giant otters select habitat according to prey abundance/availability/vulnerability criteria that may fluctuate seasonally. In Suriname Pteronura prefer slow-flowing clear black water creeks and rivers, particularly during the dry season when they prey heavily on fish that rest on the bottom in shallow water like Hoplias (pataka) and catfish (kwikwi and jacky). The availability of preferred prey species in shallow water is the governing factor in Pteronura's seasonal movements. Farther, low sloping banks with good cover and close access to prime fishing areas are preferred by otters for their campsites where they rear their cubs. All these conditions are met in Kaburi Creek from mid-September to April during the dry season making it ideal Giant otter habitat.

Group structure and behavior. Pteronura in Suriname are seen in groups ranging in size from two (a pair) to an extended family group of 7. Larger groups of 14 or more otters have been seen but these were probably two family groups traveling together from their dry season area to their rainy season area. Solitary animals, usually subadults, are transient animals passing through the area that seldom remain for long.

The ecology and behavioral repertoire of Pteronura have been described in detail in several publications and will not be reviewed here (Duplaix, 1980, Groenendijk, 1995, Laidler, 1984, Schweizer, 1992, Carter & Rosas, 1992).

Seasonal population dynamics in Kaburi Creek. The resident otters observed in 1976-1978 in Kaburi were divided into 4 to 5 groups, each occupying a territory at the height of the dry season in March of about 2-4 km in length. Each of the groups was associated with at least one of the floating grass islands areas (called "ponds" or "pans" by the Indians) along the creek that are prime fishing areas. For instance, one solitary male H1 (it lost its mate and offspring) saw his territory invaded by a larger downstream group of seven otters. Hemmed in on either side by other groups, he eventually occupied less than 1 km of river bank which centered on Arawaboo Pond, an excellent fishing area.

Each group clears a "campsite" along the bank and marks it with feces and urine, mixed with mud. The best sites, often perennial, are in key areas near fishing "ponds" or shortcuts avoiding a loop in the creek. These larger sites may have a den in the bank, and some even have backdoor exits into the forest or swamp away from the creek. Such sites are often the only areas available particularly in the upper portion of Kaburi 7-15 km from the mouth where high ground is at a premium. One group may use and mark several campsites in its territory and use several dens to rear its cubs.

Giant otters were identified individually using the variation in white spots and blotches on their necks. After a few days' observation on Kaburi Creek it was possible to recognize most of the individuals in each group along the creek. Easy individual recognition is a great asset in determining territory boundaries and group movements up and down the creek. Figure 2 shows the neck patterns of the otters seen during this brief survey.

4.The People

The Indians of Washabo. The small community of Carib and Warrau Indians in Washabo along the Corantyne river, 7 km upstream from Kaburi Creek, have been hunting and fishing in the nearby creeks for centuries. Kaburi is considered a great fishing and hunting area, indeed some of them call the creek "a holy place." They use traditional fishing methods of a single hook and short stick or bows and arrows to spear the fish, and single barrel 16-gauge shotguns for hunting. As cartridges are very expensive they hunt mainly the larger or tastier species of game such as tapir, white-lipped peccary, Mazama deer, paca, agouti and a few large birds such as Muscovy ducks or guans. As a rule they rely on fishing more than hunting for their food. They also clear patches of forest, cutting down the trees and clearing the undergrowth to plant kitchen gardens with vegetables such as cassava, bananas, beans, and squash,

The Carib Indians of Guyana. Across the Corantyne river in Orealla and Epira, opposite Washabo, are small settlements of Guyanese Warrau Indians, some of whom are related by marriage to those in Washabo. They also hunt and fish in Kaburi Creek using traditional methods. While tolerated, people in Washabo feel these "outsiders" should use creeks on the Guyana side.

The "city people" of Apura and beyond. In 1976 when I initiated my study of Giant otters in Kaburi, Apura was also a small Indian community on the verge of becoming a major city of 60,000 people. A railway was to be built by American engineers to the new bauxite mine to the south in Bakhuis, along with a major road linking Apura directly to Paramaribo, as well as a large hydroelectric dam across the upper Kabalebo river to provide power. Over the next two years, Apura grew and prospered and the boom town housed hundreds of workers and foreign engineers. Just before irreversible damage could be done the plans for this mega-project were scrapped in 1980 due to lack of funds and most of the workers left. Luckily few of the workers ventured very far up the creek in those days so the project had little direct impact on Kaburi.