THE IMPORTANCE OF BIRDS

The Importance of Birds

Birds are a diverse group, and their bright colors, distinct songs and calls, and showy displays add enjoyment to our lives. Birds are very visible, quite common, and offer easy opportunities to observe their diverse plumage and behaviors. Because of this, birds are popular to many who pursue wildlife watching and monitoring activities. Iowa NatureMapping's own database reflects this fact, in that the majority of wildlife observations reported by volunteers are birds. In fact, bird watching is the fastest growing recreational pursuit in the United States. According to the 1996 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation, we as a nation spend over 2 billion dollars on commercial bird food! Adding all wildlife watching equipment together, including bird food, binoculars, spotting scopes, film, carrying cases, etc., the nation spends nearly 20 billion dollars! In Iowa alone, we spend some 36 million dollars on bird food! Birds are not only important economically in Iowa and the nation, but also server a vital ecological role as well. Birds are critical links within the vast food chains and webs that exist in the ecosystem. Here are just a few of the many roles birds play:

Agents of Dispersal

Some birds transport a variety of things through the environment. For example, birds serve to spread seeds of various plants, thereby helping in plant dispersal. American robins feeding on mulberries eventually deposit the seeds to other locations in there droppings. Other seed and fruit-eating birds do the same thing. Hummingbirds pollinate various nectar-producing plants, transporting pollen on their beaks and feathers from one flower to the next. Even animals can be spread. Some wading birds relocate fish eggs that get stuck to their legs, thereby aiding in fish dispersal to other parts of a river or marsh. Some birds, such as the house finch, spread an eye disease called avian conjunctivitis (Mycoplasmal Conjunctivitis) through direct contact with each other or through bird feeding stations that attract them. And, although the science is still new and uncertain, both legal and illegal transportation of birds, especially the captive raised varieties such as poultry, can and has spread Avian Influenza A (H5N1) or "bird flu" across great distances in Europe, Africa and Asia. Research is ongoing, however, the precise roles played by migratory birds in the spread of H5N1 and its transmittal to domestic poultry and humans remain uncertain and continue to be debated by experts.

Biological Controls

If you’ve ever spent time on a summer evening looking up at the sky, you’ve undoubtedly seen swallows, swifts, and nighthawks swooping and gliding through the air. These aerial acrobats are consuming hundreds of insects, many of which we consider pests. These and other birds consume insects such as mosquitoes, Japanese beetles, and European corn borer moths. To feed their young, birds catch huge quantities of adult and larval insects, which are high in protein for growing chicks. Without birds, many of these insects would become even greater pests, consuming agricultural and forestry crops and produce, and our own blood!

Bio-indicators

Without birds, the effects of pollution would not have been as visible in the 1950’s and 1960’s. Perhaps the most famous environmental pollutant, DDT, is an insecticide for controlling various forest and agricultural pests, which was banned in the United States in 1972. During that time, DDT was known to kill large numbers of American Robins. In North America and elsewhere, the robin was eating insects and other invertebrates that had fed on vegetation tainted with DDT. The amount of DDT used was lethal to other wildlife as well. Various raptors, such as the peregrine falcon, bald eagle, and osprey, which fed on DDT contaminated fish and other prey, were laying eggs with very thin shells (due to the disruption of calcium uptake within the female bird). The eggs could not hold the weight of the adult birds, and thus, most eggs failed to hatch. DDT is only one example, perhaps to the extreme, of the impacts possible to birds by environmental contaminants. Fortunately, chemicals sold and used in the United States today are not as lethal or persistent as those produced in the 1950s. However, DDT and other chemicals banned in this country are still being manufactured and shipped to other countries with less strict regulations, and thus, are still impacting wild bird populations. Unfortunately, other ecological factors, such as habitat loss and degradation, are having an even greater impact on birds and other species. Many migratory bird populations are on a decline. These birds are telling us something else about the health of the environment, and the impacts we are having on it. Note: Avian Flu is yet another way birds are bio-indicators, as was West Nile Virus several years ago, which has the potential to inform us of potential threats to our own health.

                                             Prof. John Kurakar