African penguins are disappearing at an alarming rate, as commerical fishing decimates food stocks and global warming affects breeding patterns, experts said Wednesday.

"Last year there were only about 26,000 pairs of African Penguins left in southern Africa (this represents their global population) -- a decline of about 121,000 breeding pairs since 1956," read a statement issued after an international African penguin conference in Cape Town.

Research presented at the conference showed that urgent action was needed to halt the decline in the Western Cape province where the annual survival rate in key breeding colonies had halved since 2000.

"We need to understand the underlying causes. Of course, food supply must be a major factor," said researcher Peter Barham of Britain's Bristol University.

He said the food supply may have been disrupted by overfishing, or by fish stocks moving with changing ocean currents due to the effects of global warming.

Pollutants may also have weakened penguins and affected their ability to find fish.

"Other issues affecting penguins include increased predation by fur seals around some colonies, the continuing risk of oil spills, and as the climate warms up, the lack of suitable, cool, places to breed within the traditional colonies."

In recent years researchers have set up nesting boxes in colonies to shelter the birds from the heat and protect eggs from opportunistic gulls.

Sardines and anchovies, their major source of food, have been affected by fishing and sea temperature changes, pushing penguins to form new colonies closer to food supplies.

The African Penguin, also known as a jackass penguin because of its donkey-like bray, is the only species of the charismatic animal which breeds in Africa and is found only around southern Africa.