The Lake Chad is an important ecological niche for thousands of migratory birds. More than 350 bird species have been listed there. The Lake Chad is a wet zone of international importance (Ramsar sites) recognized in Cameroon, Chad, Niger and Nigeria. But persistent drought conditions, coupled with increased demand for freshwater for irrigation, have reduced Lake Chad to about 5 percent of its former size. As the waters receded, the silts and sediments resting on the lakebed were left to dry in the scorching African sun.