The greater flamingos (Phœnicopterus roseus) are morphologically adapted to the optimal exploitation of the very particular environments they need to survive and are the only species of birds to be satisfied with mud as their only food resource. Thanks to their long legs and exceptionally flexible necks, they can trample the ground in a few inches of water as well as venture up to a few feet deep or swim and dive. Their beaks with filtering lamellae and salt evacuation systems also allow them to feed on the 6 to 8% of organic matter contained in the highly alkaline and salt-saturated silt of the waters they frequent.