Complex sentence: The species breeds well in captivity, and has been successfully re-introduced; in 2004, it was estimated that there were 800 birds in the wild, as well as 1,000 in wildfowl collections and zoos.
Split into simpler sentences: The species breeds well in captivity, and has been successfully re-introduced. In 2004, it was estimated that there were 800 birds in the wild, as well as 1,000 in wildfowl collections and zoos.