CONSERVATION OF THE RIVER DOLPHIN (INIA BOLIVIENSIS) IN BOLIVIA - Biology, Evolution and Conservation of River Dolphins Within South America and Asia - page 58

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a

-10

N

Cachu ela Esperanza

ß

A

-11

BRAZIL

PANDO

-12

-13

BENI

-14

-15

LA PAZ

u

-16

SANTA CRUZ

COCHABAMBA

-17

Figure 1. Distribution of the river dolphin, bufeo ( Inia boliviensis ) in the three sub-basins in Bolivia. In
the Abuna sub-basin, there is a possible presence of I. geoffrensis. “ Cachuela Esperanza‖ is the
beginning of the rapids that extends to Brazil and isolates Inia boliviensis .

In the Mamore sub-basin, the bufeo is located all along the Mamore River, from the
Ichilo River (in Cochabamba) to the Guayanamerin in Beni, including most of their
tributaries, such as Sécure, Ibare, Tijamuchi, Apere, Abuná, Rapulo, Itonamas, Yacuma,
Yata, Mariquipiri, Baures, and Chapare rivers close to the confluence of the Rio Grande . The
indigenous group, the Yuracaré, along the Chapare River have reported the presence of the
bufeo close to the community of San Antonio (16º 56'45.4''S- 65º 22'42,9''W, approximately
600 m above sea level) only during the rainy season when the river current is rapid and there
is strong turbulence (J. Flores, I. Soria, N. Chavez 2007 com. pers.). This might be the highest
elevation for the species, the previous highest elevation being 380m, close to the Puerto
Villarroel on the Ichilo River, in the same sub-basin (Pilleri & Ghir, 1977).
The bufeo is not registered in the Madre de Dios and Beni sub-basins, probably because
these rivers are isolated by rapids, principally in the area called ―Cachuela Esperanza‖ that
form a natural barrier to the Mamore River (Figure 1). Pilleri & Ghir, (1977) and Tello,
(1986) indicated the occurrence of the bufeo in the Beni River, but these reports may be
inaccurate reports because small tributaries of the Mamore sub-Basin are only a few
kilometers from the reported area (Anderson, 1997). For example, in a town close to the Beni