A thriving "hotspot” of 1.5 million Adelie penguins, a species fast declining in parts of the world, has been discovered on remote islands off the Antarctic Peninsula, surprised scientists said yesterday.

The first bird census of the Danger Islands unearthed over 750,000 Adelie breeding pairs, more than the rest of the area combined, the team reported in the journal Scientific Reports.

The group of nine rocky islands, which lie off the northern tip nearest South America, in the northwest Weddell Sea, housed the third- and fourth-largest Adelie penguin colonies in the world, they found.

"It is certainly surprising and it has real consequences for how we manage this region," study

co-author Heather Lynch of Stony Brook University told AFP.

Just 160 kilometres (100 miles) away on the west of the peninsula -a thin limb jutting out of West Antarctica — Adelie numbers have dropped about 70 percent in recent decades due to sea ice melt blamed on global warming.

“One of the ways in which this is good news is that other studies have shown this area (the eastern side of the Antarctic Peninsula) is likely to remain more stable under climate change than the western Antarctic Peninsula," said Lynch.

“So we end up with a large population of Adelie penguins in a region likely to remain suitable to them for some time."

Adelies are one of five penguin species that live in and around the Antarctic continent.

A medium-sized penguin, they grow to about 70 centimetres (almost 28 inches) tall, and weigh three to six kilogrammes (about seven to 13 pounds). They are identified by a white ring around the eye.

They are carnivores, and krill -shrimp-like creatures that are commercially fished in the area -- is an Adelie staple.

The Danger Islands group was discovered thanks to Earthmonitoring satellites, said the research team from America, Britain and France.