For a nation largely composed of desert, Saudi Arabia has fairly valuable biovariety. Eighteen % of its invertebrate animals, seven of its nine amphibians, and all of its indigenous freshwater fish are found nowhere else. There are an around 3,500 species of plants and 59 terrestrial mammals, 19 of which are endangered, vulnerable, or rare. Government-sponsored wildlife teams are working to increase populations of threatened houbara bustards and Arabian oryx. In addition, there are 413 recorded species of birds, 11 of which are rare or endangered.