Thursday, August 28, 2008
Fledgling biologist, Malcolm Kellermueller, releasing Burrowing Owls that were mitigated and relocated from a construction site in Santa Fe, New Mexico by Hawks Aloft, Inc. The owls were safely excavated from prairie dog burrows, and relocated to an adjacent lot that had an active prairie dog colony with vacant burrows for them to utilize.
Tuesday, August 12, 2008
Western Meadowlark. Photo by David PowellI caused the death of a songbird. Certainly more than one bird, and possibly a hundred or more, died because of me. I didn’t mean to do it. In fact, I was oblivious to their silent suffering and desperate demise. It was the winter fruits and vegetables that did it, those seemingly healthy foods that the doctor recommends. They make up a large part of my diet throughout the year. I have a particular fondness for grapes, bananas, asparagus, peppers, and that standard American staple, coffee.
One of the indicators of the changing season is the annual return of bird song. Many of us look forward to the return of our feathered friends from their wintering grounds. We take for granted that their song will fill the spring air with cheerful sounds. But, each year, as we continue to demand out-of-season fruits and vegetables, fewer and fewer songbirds return. Just as the Bald Eagle, Peregrine Falcon, and Osprey were the proverbial canaries in the coal mine that warned us of the dangers of DDT, and changed pesticide use in the United States, today’s songbird populations are an important environmental indicator.
Land management plans in North America now include provisions designed to protect migratory songbirds, including virtually all federal, and most state plans. Many land managers have changed the way they manage to allow for the needs of songbirds and other wildlife, and support research to develop methods to maintain healthy populations. Ambitious projects are underway to permanently protect large swaths of acreage for birds, particularly grassland and boreal forest species. Because of their role as environmental indicator species, avian conservation measures have become part of global efforts to protect biodiversity, not just for birds, but for all life.
Many of our summer residents winter in Central and South America, where highly toxic pesticide use has caused steep declines in bird populations. Pesticide use has increased 500% since the 1980s in Central America as these countries have increased their production of crops to fuel our demand for fresh produce during the winter. The chemicals include monocrotophos, methamidophos, and carbofuran, all of which are rated Class I toxins by the World Health Organization, are highly toxic to birds, and are either restricted or banned in the United States.
In some cases, the poisonings are indirect such as the 1995 deaths of 20,000 Swainson’s Hawks on the pampas of Argentina. Farmers had sprayed monocrotophos, an organophospate on their fields to control grasshoppers, the primary food item of wintering Swainson’s Hawks. Thanks to the efforts of the American Bird Conservancy and other organizations, Novartis (formerly Ciba-Geigy), a major manufacturer of this pesticide, has agreed to phase out production and sale of monocrotophos. Additionally, a major effort has taken place to educate farmers about the benefits of these insect eating hawks and other birds that help keep insect populations under control.
In other instances, birds like the Bobolink, meadowlarks, and other grain eating birds are viewed as pests as they feed on the crops intended for humans. They are directly poisoned to minimize crop damage. The Bobolink, in particular, has suffered a 50% decline in the last 40 years, according to the Breeding Bird Survey.
Americans, however, shouldn’t feel too smug about our environmental record when it comes to pesticides. On a global scale, over 5 billion pounds of pesticides are used annually for agriculture, forest and rangeland management, disease control, and on private properties. In the United States alone, we use 1.2 billion pounds each year. Many of the most toxic chemicals, including DDT, have been banned in our country. However, the U.S. continues to export DDT as well as other pesticides known to be hazardous to the environment and to human health. Conservative estimates place the of the number of birds killed in the U.S. each year due to pesticide ingestion at 67 million. This represents 10% of the 672 million birds annually exposed to pesticides in our country alone.
South of our border, human pesticide exposures continue despite workers’ improved awareness of the dangers. Most Central American countries have few regulations for effective controls for pesticide use, and in 1998, (most current figure available) almost 6,000 human poisonings were reported in Central America. Ironically, while we have increased our reliance on winter produce, Mexico, a major importer of that produce, has increased its dependence on pesticides. It is currently the second largest pesticide importer in Latin America.
We have effectively created a circle of poison in which pesticides outlawed in the U.S. because of documented toxicity are exported to Third World Countries that use them to grow the crops that are, in turn, sold to the American consumer. Testing by the U.S. Food and Drug Administration shows that produce imported from Latin American countries is three times as likely to violate Environmental Protection Agendy standards for pesticide residues., Some, but not all pesticide residues can be removed by washing or peeling produce, but tests by the Center for Disease Control show that most Americans carry traces of pesticides in our blood. We, however, show few if any signs of that oxicity. It just may be that our beloved songbirds might be the first indicator of threats to our health.
As American consumers, our most effective tool is our wallet. Next time you shop, buy locally grown foods wherever possible. Not only will you reduce your pesticide exposure, you will be purchasing food with a smaller carbon footprint.
Purchase organic, shade-grown coffer. Most mass produced coffee is heavily treated with fertilizers, herbicides, fungicides and insecticides. Shade grown coffee is grown beneath a canopy of tropical trees, which provide shade, essential nitrogen, and leaf litter for fertilizer.
Organic bananas should on your list. Although our pesticide exposure from bananas is minimal because we peel the fruit, bananas are grown with one of the highest pesticide loads of any tropical crop.
Purchase produce such as melons, green beans, tomatoes, bell peppers, and strawberries only if they are not grown in Central America.
The birds, and your great grandchildren will thank you for it.
Perhaps running on water might be a more appropriate term for part of the captivating courtship ritual of these two closely related, fascinating species. Not considered ducks, geese, or even waterfowl, these less commonly observed birds are considered just “waterbirds”, a somewhat ignominious term given their spectacular breeding season displays considered to be among the most complex known in birds. Those of you lucky enough to have witnessed the event will likely always remember it. Certainly, it is frequently shown on television nature shows. After a series of calls and posturing, the pair rises up on their feet, and with wings beating furiously, literally run across the surface of the water. A second ritual, “the weed ceremony” cements the pair bond. Beginning like the prior example, a weed dancing couple simultaneously dive to the lake bottom to gather a mouthful of vegetation, rise to the surface, and then rise on the their feet while holding the vegetation bill-to-bill.
Clark’s and Western Grebes are remarkably similar in appearance, with only subtle differences in facial pattern, bill color, and calls to differentiate the birds to our human eye. In fact, the two are so similar that from 1886 to 1985 they were considered to be one species. Highly social, they can be found on our larger lakes, particularly those with the marshy vegetation necessary for nesting during the spring. During winter, on open water, they may be found in large rafts of both species, where they hunt mainly for small fish and other aquatic animals, which are usually swallowed underwater, a seemingly impossible, if not illogical feat. Furthermore, each individual can consume up to a pound of fish a day, so large groups are capable of quickly depleting the food resources in a small pond or lake.
Superbly designed to efficiently ‘fly’ underwater, grebes have short wings and feet and legs that are positioned near the rear of their bodies, making them ungainly on land. In fact, most grebes rarely set foot on terra firma, except during the nesting process. Grebes almost never fly except during migration which occurs at night. Additionally, grebes, replace most of their feathers all at one time, rendering them flightless for much of their nesting period. This effectively restricts their range to the pond or lake that they selected for their nest site, and subjects the pair and their young to the perils of uncertain weather, water levels, and adequate food supplies.
Nestling grebes are able to swim and dive within 24 hours of birth, but are not terribly water-proof. Like loons, a closely related species, young grebes spend most of their early weeks riding on the backs of their parents. At this time of year, young grebes are independent of their parents and might be found in close company with others of their kind. Check out the lakes of New Mexico for a look are these rare and interesting birds! If you’re lucky you might even see the dance!