What makes Virginia attractive to different species, at different times? There's a reason why the tourists go where they go, when they go, in Virginia. We know the tourists flock to places like Williamsburg in the summer because school is out of session then, and families can vacation together. The young folks who "hit the beach" in the summer are driven in part by the seasons; body surfing the waves or cruising the boardwalk in a bikini makes sense only between May and September. And the leaf-lookers crowding the highways to Shenandoah National Park in October are getting a peek at the peak Fall colors.
Just as different areas of Virginia attract different tourists during different seasons, the state offers a wide range of habitats for wildlife at different times of the year. The birds are as selective as a family with teenagers choosing where to vacation for a week. Some habitats that attract birds are natural, but others are man-made. For example, Chincoteage National Wildlife Refuge manages 2,600 acres of ponds known as "moist soil management units." By raising and lowering the water at different times of the year, the refuge biologists can attract the ducks, herons, geese, and other aquatic birds.
In the case of the birds, there is a long history of natural selection that affects who goes where, when. Thousands of snow geese (Chen caerulescens) migrate each Fall to the marshes on the Chesapeake Bay and the Atlantic coastline. They show up from Assateague Island all the way south to Back Bay National Wildlife Refuge. In the Spring, they leave - because the Canadian wetlands offer more food and fewer predators on nest sites than the Virginia marshes. How do they know where to go, and when to go?
Image Credit for birder with binoculars: US Fish and Wildlife Service