CAPE TOWN, Dec. 5 (Xinhua) -- Endangered African penguins living off the coast of South Africa have likely starved to death in large numbers due to severe food shortages, according to a new study.

The study, conducted by an international team of researchers from the South African Department of Forestry, Fisheries and the Environment and the University of Exeter in the United Kingdom, was published on Friday in Ostrich: Journal of African Ornithology.

The global population of the African penguin (Spheniscus demersus) fell below 10,000 breeding pairs for the first time in 2023, prompting the International Union for Conservation of Nature to list the species as "critically endangered" in 2024. Conservation organizations said earlier this year that at current rate, it will likely become extinct in the wild by 2035.

According to the study, on two of the most important breeding colonies of the African penguin near Cape Town -- Dassen Island and Robben Island -- some 95 percent of the birds that bred in 2004 were estimated to have died over the following eight years due to food scarcity.

"Between 2004 and 2011, the sardine stock off west South Africa was consistently below 25 percent of its peak abundance and this appears to have caused severe food shortage for African penguins, leading to an estimated loss of about 62,000 breeding individuals," said Richard Sherley, the study's co-author from the Center for Ecology and Conservation at the University of Exeter, in a statement released by the university.

The study blames changes in the temperature and salinity of the west coast of Africa for making spawning of sardines -- a main food source for penguins -- less successful.

In their research, Sherley and his colleagues analyzed counts of the number of breeding pairs and moulting adult-plumaged penguins on Dassen and Robben islands from 1995 to 2015.

"These two sites are two of the most important breeding colonies historically, holding around 25,000 (Dassen) and around 9,000 (Robben) breeding pairs in the early 2000s," said co-author Azwianewi Makhado from the Department of Forestry, Fisheries and the Environment.

Losses are not just confined to Dassen and Robben, the team noted. "These declines are mirrored elsewhere," Sherley said, adding that the species has undergone a global population decline of nearly 80 percent in the last 30 years.

In the University of Exeter's statement, the researchers noted that their findings could have important relevance to management strategies to help secure the long-term survival of the birds.