LJUBLJANA, Slovenia (AP) — A zoo in Slovenia’s capital Ljubljana has presented its newest residents: three Siberian tiger cubs who were born there under two weeks ago. The Siberian tiger is one of the world’s most endangered big cat species, with experts estimating that about 500 remain in the wild. Their survival is threatened primarily by habitat loss and poaching. Zoo workers said the cubs were born to mother Arisa and father Ussuri, which arrived in Ljubljana in 2004, after careful planning