Dolphin Romance

Amazonian dolphins say it with weeds

Article from: Agence France-Presse

From correspondents in Paris

December 06, 2007 04:30am

A MAN may bring flowers to impress women, but male Amazon river dolphins carry weeds to win over the opposite sex, British and Brazilian researchers said.

The discovery comes from a three-year study of more than 6000 groups of dolphins in Mamiraua, a flooded rainforest reserve in the Amazonian, British weekly New Scientist reports in its next issue.

Of these groups, 221 included at least one dolphin, usually a male, that carried an object, such as weed, a stick or clay. The groups also usually contained an adult female.

Aggression between adult males in the "object-carrying groups" was far higher than in other groups, which points to the carrying behaviour being a sexual display rather than a form of play, said the researchers.

The interpretation is backed by genetic analyses of tissue samples collected from adults and calves that suggests some of the most frequent object-carriers are among the most successful fathers.

Only humans and chimps are known to do anything similar as a show of prowess to win over a mating partner.

The research, led by Tony Martin of the British Antarctic Survey (BAS) and Vera da Silva of Brazil's National Institute of Amazonian Research, was presented last week at a conference on marine mammals in South Africa last week.