there are 29 species of endangered or critically endangered mammal, 40 species of bird, 20 species of reptile and 14 species of fish listed in the 2011 edition of the "red data book of turkmenistan". the mountainous area of kopet dag is under threat from overgrazing by cattle with much of the forest having been cleared for firewood. soil erosion creates mud flows when heavy rains occur, damaging woodland lower down the slopes and riverside habitats. conversely, particularly dry summers have created conditions where wild fires are frequent, and this puts at risk the unique communities of fruiting trees and the rare mammals.