2 . As seabird biologist Bonnie Slaton slides off a small boat and walks through high water, the brown pelicans (鹈鹕) spread their wings overhead until she reaches Raccoon Island. The narrow island is a small piece of land separating the American state of Louisiana from the Gulf of Mexico. During the seabird breeding (繁殖) season, the placer, one of the few remaining places of safety for the pelicans, is full of noise.

Twelve years ago, there were 15 low-lying islands with breeding areas for Louisiana’s state bird. However, today, only about six islands in southeastern Louisiana have brown pelican nests and the rest have disappeared underwater.

Slaton and other scientists set u cameras to observe pelican nests on the island. The cameras show that in recent years the pelicans have faced some natural disasters. The main killer of them is flooding, which can wash away all the nests, as happened in April 2021. The disappearing islands are the location of a story of successful conservation. For many years, scientists have worked to bring the pelicans beck from tally dying off.

Mike Carloss is a state wildlife biologist in Louisiana. He said he never saw brown pelicans as a child in the 1960s. Their populations had been killed by the use of DDT, a kind of farm chemical. It thinned eggshells and prevented pelicans from giving birth to young birds. The beloved birds were completely gone from Louisiana, only appearing on the state flag. But a long-running effort to save them led to the birds’ return. After DDT was stopped in the U.S. in 1972, biologists brought young pelicans from nearby Florida to let them inhabit empty islands across the Gull of Mexico again. More than 1,200 pelicans have been set free in southeastern Louisiana over 13 years.

The brown pelicans can live more than 20 years. So, the final effect of disappearing breeding areas is uncertain and it will sill take time to become clear. And the future for pelicans is uncertain on the islands.