Come winter, however, and many of the songbirds migrate south. In return, Virginians get to see juncos and snow geese, visitors from the north who consider Virginia winters to be mild compared to Canada. Virginia provides a suitable place to live, but as the climate changes those habitats change. The most obvious change is in the forests - when the leaves drop, much of the food and shelter required by some species disappears too. Many species of animals, such as neotropical birds, adapt to the changing circumstances by picking up and moving - at just about the time students migrate to college campuses.
Plants lack that option.
Take a close look outside the car window, the next time you are trapped in traffic. Notice the different types of plants along the roadside. Do this several times, and you'll begin to see the pattern. Some places are treeless, such as the mowed edges of the roads or the medians in divided highways. Look at the forested areas, and notice how few wildflowers are visible on the ground.