New Delhi, Jan. 20 -- Warming temperatures are forcing Antarctic penguins to breed earlier and that's a big problem for two of the cute tuxedoed species that face extinction by the end of the century, a study said.

With temperatures in the breeding ground increasing 5.4 degrees Fahrenheit (3 degrees Celsius) from 2012 to 2022, three different penguin species are beginning their reproductive process about two weeks earlier than the decade before, according to a study in Tuesday's Journal of Animal Ecology. And that sets up potential food problems for young chicks.

"Penguins are changing the time at which they're breeding at a record speed, faster than any other vertebrate," said lead author Ignacio Juarez Martinez, a biologist at Oxford ...