Conservation through having smaller families

This population classic, a short, illustrated book by Nola Stewart that was originally written in 1982 and has been updated multiple times since, has been both updated again this year and also turned into a series of YouTube videos:

Part A

http://www.youtube.com/watch?v=KUgcw-TxGDA

Part B

http://www.youtube.com/watch?v=5wBUIP9Foco

Part C

http://www.youtube.com/watch?v=Vgn7WSbRcSs