"'We're 40 percent paved over, so there's not much nature left,' he said, shrugging. With a growing population of 200,000, the 26-square-mile county might be reaching a 'critical mass' of dense urban landscape, he said, where even the hardiest wild survivors, such as skunks, can no longer make it. Hodnett, a wildlife biologist in Fairfax County, which has a healthy skunk population, says he has a hard time believing the animals have disappeared from Arlington. 'It would really raise questions about our own quality of life,' he said. 'If a skunk can't make it here, how are we doing?'"