National Geographic : 1995 Apr
Shooed down by a waving flag, a koala on Vic toria's Raymond Island submits to a research roundup (left). Once bagged (below), it is fitted with a radio collar and checked for chlamydia, a bacterium that plagues koalas across Australia. Aggravated by stress, infection can cause con junctivitis, urinary-tract disorders, sterility, and even death. "We don't see the outward signs of chlamydia on the island, but reproduction is very low," says veterinary pathologist Peter Mitchell. New addition to the colony, a pouch young is mea sured to determine its age (above).