Authorities are scrambling to save hundreds of starving and endangered Dalmatian pelicans after the Caspian Sea froze for the first time in years.

Hundreds of the birds with distinctive curly feathers at their napes are jostling one another in a patch of unfrozen water at a shipyard near the city of Makhachkala, the capital of the southern Russian province of Dagestan.

About 20 birds have died of hunger despite hundreds of pounds of fish that Dagestan's Nature Protection Ministry are buying each day to feed them, spokesman Arslan Dydymov said.

Fewer than 1,400 Dalmatian pelicans, the world's largest, live in southern Russia.

The birds are getting sprats from the local market because fresh fish from the iced-over Caspian is not available.

"Yesterday it seemed they ate more than enough," said Kurban Kuniev of the Dagestan nature reserve.

The birds flew to Makhachkala last week from the frozen deltas of the Volga and Terek rivers up north. Local residents were so excited by the arrival that the guards at the Makhachkala shipyard had to stop hundreds of people from entering with bread and other unsuitable foods.

"We did not let them in for the sake of the pelicans," chief guard Magomed Eldarov said.