Erik Patel's documentary of the Sifaka in the rain forest of Madagascar describes how this particular species of lemurs is now on the brink of extinction. Patel explains that the Sifaka's habitat has been destroyed by illegal logging of rosewood trees in the Marojejy Park.
It must be those Disney movies but I keep picturing the swans actually singing for the lemurs.
Solana, When the Hollywood animation film was released in 2005, Conservation International had hoped that the movie would help save the lemurs by promoting eco-tourism in Madagascar (WSJ). Maybe a sequel along the lines of what you pictured could help revive that idea :).