Cow hide. Classic posters advertising Akubra Hats.  Stick to Akubra Hats!  See or buy on line at http://www.akubra.com.au/  Copies made in China are not the real McCoy.  Rabbit's fur goes into the manufacture of the felt hats and the fur is even imported when local supplies are low.  Rabbits are largly eradicated.  They were in plague proportions once as a result of their introduction to our shores.