MSN: Anacondas, giant otters and the world’s largest bird of prey proved to be worth more than their weight in gold when dredging for the metal was banned in their forest home, conservationists have said. The ban on gold dredging in the unspoilt region of Guyana follows a campaign by Amerindian villagers, backed by scientists from the Zoological Society of London. PhD students Rob Pickles and Niall McCann travelled to the Rewa Head in the South American country to study giant otters …