MONTEVIDEO: About 2,000 penguins have appeared dead on the coast of eastern Uruguay in the last 10 days, and the cause, which does not appear to be avian influenza, remains a mystery, authorities said.The Magellanic penguins, mostly juveniles, died in the Atlantic Ocean and were carried by currents to Uruguayan shores, said Carmen Leizagoyen, head of the Environment Ministry's fauna department.