BOSTON - Warm ocean currents may have confused some 2,500 penguins from Argentina's Patagonia region that washed up -- dead and alive -- on Brazil's northern coast.

Magellan penguins (Spheniscus magellanicus). Peter Johnson—Natural History Photographic Agency/EB Inc. About half the penguins that were found on Brazilian beaches in October were dead, and the others were starving and in very bad shape, said Valeria Ruoppolo, an emergency veterinarian with the International Federation for Animal Welfare (IFAW), in Sao Paulo, who coordinated the rescue of many of the penguins.

"Of the live ones, about 50 percent survived," Ruoppolo told Tierramérica.

Magellan penguins (Spheniscus magellanicus) live in relatively warmer climates than other penguin species, and breed and nest in burrows in the southern hemisphere spring and summer, from October to February, in southern Chile and Argentina, in a temperate and dry climate.

They travel out to sea during the winter, from March to September, to follow anchovies, their favorite food, in order to fatten up.

Juveniles also migrate north. This year, about 2,500 disoriented juvenile penguins traveled more than 2,500 kilometers beyond the normal point, coming ashore in Salvador, in Bahia state, 1,400 kilometers north of Sao Paulo, to the amazement of beachgoers. The penguins were rescued by IFAW and the Center for Marine Animal Recovery, with help from other organizations and Brazilian environmental authorities.

After months of care and feeding, the 372 surviving penguins were banded and loaded onto a C-130 Hercules military plane and transported to Cassino Beach, in Pelotas, in southern Brazil.

After an overnight rest, they were released into the South Atlantic ocean, along with a few other rescued adult penguins, with the hope that they would guide the younger ones safely home to Patagonia.

About 200 people cheered them on as they waded into the surf. It was the largest penguin rescue on record, a success for animal welfare experts -- but a terrible omen for the penguin population.

"We always have a few strandings here and there. In 1994 and 2000 we had big strandings. But not like this year. More than 2,000 penguins is unheard of," Ruoppolo said.

Magellans are one of 17 species of penguins, which all live in the southern hemisphere, including the Antarctic. Magellans are among the largest, weighing just over four kilograms, with striking coloring: a white chest and a white band around a black back and black head.

The Magellan penguin population is fragile, as their numbers have plummeted by about 20 percent, with about one million breeding pairs today, according to the Wildlife Conservation Society. The penguins are at risk due to the effects of climate change, tourism, oil leaks from tankers and shrimp nets.

"We are going to try and understand what happened," using the identification bands as a tool, Ruoppolo said.

Once the penguins reach their home colonies, volunteers and researchers there will notify Ruoppolo. She will aggregate data about the climate, ocean currents and food sources, to learn about the strandings.

"One thing that was different is that the surface of the Atlantic ocean was one degree Celsius warmer. The penguins follow the fish, especially their favourite, the anchovies. Probably what happened this year is the anchovies went deeper into the ocean for the cold water. And the penguins couldn't reach their food and they stranded because they were starving," she said.

However, Ruoppolo warned, "We don't know yet if we can link the strandings to climate change. Soon we will be able to say."

According to Sybille Klenzendorf, a scientist with the World Wildlife Federation (WWF), "It's probably not going to be unusual for some of these things to happen," given the rise in temperature of the ocean.

The ocean environment of the southern tip of Patagonia especially is undergoing alterations, Klenzendorf said. Due to glaciers melting, the salinity of the water there is changing.

"The salt content is becoming less. It's not just the temperature that is changing," she told Tierramérica.

WWF scientists recently warned that allowing the earth's surface temperatures to rise an average 2 degrees Celsius further -- which is expected within 50 years even with a reduction in greenhouse gas emissions -- will severely endanger Emperor (Aptenodytes forsteri) and Adelie (Pygoscelis adeliae) penguins and other Antarctic wildlife.

The current targets for reducing greenhouse emissions "aim at stabilizing the climate at 2 degrees higher than it is today. But what we're saying is we need to be more conservative than 2 degrees," Klenzendorf said.

Furthermore, stress from the ocean changes would exacerbate an already dwindling source of fish for the penguins, due to aggressive commercial fishing in the region, she said. During nesting season, male penguins are swimming further each day to feed, compared to their normal forays, according to P. Dee Boersma, a penguin expert at the University of Washington.

Boersma, who has a research station in Punta Tombo, home to the largest colony of Magellan penguins, on the coast of the southern Argentine province of Chubut, says the changing climate has included more rain in recent years.

Coastal Patagonia is normally very dry, and the increasing rains mean that wet penguin chicks die of exposure, Boersma says in research published recently in the journal BioScience.

"Penguins are sentinels of the marine environment, and by observing and studying them, researchers can learn about the rate and nature of changes occurring in the southern oceans," she says.

Punta Tombo is a tiny peninsula near the city of Rawson. Its widest point is less than one kilometer, and it is teaming and crowded with penguins -- and tourists -- during breeding season. About 105,000 people visited the penguin colony in 2007. Local efforts are underway to protect the penguins from further encroachment.

In 1982, the Punta Tombo colony was saved from Japanese commercial interests, which wanted to slaughter the birds and use their pelts to make golf gloves. The area was turned into a penguin preserve and research center, led by Boersma.

This story was originally published by Latin American newspapers that are part of the Tierramérica network. Tierramérica is a specialised news service produced by IPS with the backing of the United Nations Development Programme, United Nations Environment Program and the World Bank.