Species diversity in Costa Rica can in part be traced to its land formation. After millions of years of earthquakes and volcanic eruptions, the previously separate American continents eventually became connected. The stretch of land between continents—now Central America— contains what might be expected of a bridge: representation of species from both continents. Bird species began migrating to the area many millions of years ago. Birds such as the jay came from the north, while hummingbird species appeared from the south.
In addition to its bridging geography, Costa Rica has abundant fruits and flowers. Birds that feed mostly on nectar or fruit are increasingly rare at locations away from the equator. With trees fruiting all year in Costa Rica, even birds like the Resplendent Quetzal can survive on diets that are nearly exclusive to certain fruits. Birds such as the Violet Sabrewing or Great Green Macaw, with vibrant colors and fascinating life cycles, have many kindred species in Costa Rica.
Fruits and flowers provide birds with food, but many of these plants also rely on birds. In the neotropics, hundreds of bird species fill the important ecological role of dispersing fruits and pollinating flowers. The bird’s mobility makes them an ideal carrier. However, with high mobility, bird communities require large areas of land to survive. Thus, birds are strongly affected by human alterations and fragmentations of the forest. Because many plants, in turn, rely on birds to access adequate habitat, isolating forest fragments creates a feedback loop of species reduction. With accelerating loss of birds and plants, deforestation becomes a serious problem. The conservation of large land areas is very important to maintaining these species in the tropics.