Boto (Amazon River Dolphin)

The boto is less threatened than the other river dolphins although as human populations increase throughout Amazonia, there is likely to be increasing demands placed on their population. There are three recognized subspecies of boto based on their geographical distribution as distinct populations, these are:

Subspecies: Orinoco dolphin (I. geoffrensis humboldtiana) which is found in the Orinoco basin in Venezuela.

Subspecies: Amazon dolphin (I. geoffrensis geoffrensis) which is distributed widely throughout the Amazon basin except for the Madeira drainage basin in Bolivia above the Teotonio rapids and,

Subspecies: Bolivian dolphin (I. geoffrensis boliviensis) in the upper Madeira drainage basin in Bolivia.

Population size: There are no current figures that accurately reflect the population size but, due to their wide distribution through what is thought to be close to their historical range, their numbers are thought to be in the region of tens of thousands.

Distribution: As described above. Botos are found in slow moving streams and rivers and move in to flooded forest areas during the high water season.

Threats: Botos are seldom killed by fishermen at present although this might become more prevalent as competition for fish increases. They are occasionally caught incidentally in fishing nets but there is far greater threat from damming projects that threaten to fragment current populations. Several damming projects have already done this but there are many more proposed for the future. In addition to this, open cast mining activities along the shores of the Amazon River system for gold and other precious metals have meant that there is a heavy threat from pollutant chemicals such as mercury which escape into the water systems. These events are becoming all too common.

Interesting Facts: The boto is also known as the Amazon River dolphin or pink river dolphin and is perhaps the best known of all the river dolphins due to its pale colour and striking appearance. It has an extremely long beak and a flexible neck that allows it to move its head around in most directions due to a number of vertebrae that are not fused. It has a bulging melon and chubby cheeks with small eyes and is known to occasionally swim upside down. The boto are revered by local indigenous peoples throughout the Amazon as having mystical powers and there are many myths attached to them, notably the seduction of young women.