As the weather gets warmer, hundreds of herons have arrived at the cliffside along the Yellow River in north China's Pinglu County. Every year from March to July, they make nests here to lay and hatch their eggs. Herons are large birds with long legs and long beaks, which live near water and eat fish. Since 2010, local officials have zoned the nearby 20 square kilometers as a protected area to ensure the birds are not disturbed.