Tuesday, March 30, 2004

Urban Black Vultures
Formidable looking, the large black vulture is often considered a nuisance in residential suburbs of the Southeastern United States. A news report from Virginia indicated that calls complaining of property damage rose from 2 in 1990 to 174 in 2001--making it the third most destructive wild animal in the state.

Though many might consider this a recent phenomenon--with wild birds now being encroached upon by residential subdivisions, in actuality, black vultues have been fixtures of urban areas since the first cities were built in the American South. Alexander Wilson reported the birds in Charleston, SC in the early 1800s, and a few years later, John J. Audubon even reported that the birds would warm themselves on chimneys in cities. They were considered ugly but useful for cleaning up the cities--even though they were known to occasionally vomit down chimneys!

In the age of high tech manufacturing, a black vulture roost on a power tower in Austin, Texas was implicated in creating small variations in current flow that caused havoc with local computer chip manufacturers that need a steady and stable electrical stream.

Black vultures love power towers, with their high exposed perches and clear lines of flight making it easy to land and take off in the evenings and early mornings.

Especially problematic roost sites might be dispersed with installation of architectural bird control devices such as Nixalite--a bristly wire strip that discourages birds from perching.

Urban vultures...another sign of the times. As long as we provide roost sites and a source for food, these creatures will be watching us from a perch in our neighborhoods.

Saturday, March 20, 2004

Endangered Domestic Waterfowl
Though domestic birds are not usually considered as conservation priorities, a recent census of domestic duck and waterfowl breeds in the United States finds that many breeds are threatened with extinction. According to the American Livestock Breeds Conservancy (ALBC), 10 domestic duck breeds have populations below 500 individuals, with several breeds reduced to single breeding populations.

Even some of the more familiar breeds in your local park may be threatened, such as the Chinese Goose (photo) which is reportedly down to fewer than 5000 birds.

The domestic ducks you see at your local park are just the tip of a rich cultural and genetic waterfowl heritage created by hundreds of years of dedicated waterfowl breeders. While urban bird conservation is focused on protecting and preserving populations of native birds, the loss of any of these duck or geese breeds would also be a tragic cultural and genetic loss.

Friday, March 19, 2004

Acid Rain and Birds
Two years ago, researchers announced that acid rain might be linked to declines in Wood Thrush and other bird populations in the N.E. United States (full report here). Acid rain is produced when sulfur dioxide (SO2) and nitrogen oxides (NOx) mix with cloud moisture before falling to the earth as rain. Acid rain has many negative effects, and can only be stopped by reducing airborn pollutants caused by burning fossil fuels.

Apparently, acid rain leaches calcium from soils, which seems to impact availability of calcium for birds that are egg-laying, though the exact mechanisms have yet to be identified.

The EPA's market-based Acid Rain Program reduced acid rainfall in the 1990s, but the Sierra Club and National Audubon Society report that Bush's additional market-based Clear Skies proposal will have a negative impact on human and bird health.

Just like a canary in a coal mine, the fate of the wood thrush may be forshadowing our own fate if we cannot regulate our industrial and urban society's auto and power plant emissions .

Monday, March 15, 2004

Bird Feeding May Be Killing Birds
According to research (read report here) conducted by Caesar Kleberg Wildlife Research Institute biologist Scott Henke, bird feeders may unwittingly poison many of the birds attracted to seed in their yard. The poison is aflatoxin, a harmful chemical produced by Aspergillus fungus commonly found growing on commercially available bird seed--especially mixtures that include dried corn--and exposure to the chemical at small doseages disrupts the immune system of birds, and higher doseages cause bird mortality.

Bird feeders should keep bird seed from becoming moist, though the fungus can grow even in drier conditions. Only storage of sealed containers of bird seed in a freezer appears to prevent the fungus from growing on bird seed.

Bird watching and conservation organizations in the U.K. seem to be more aware of this threat than those in the U.S. As of today, there is no mention of aflatoxin on the websites of Wild Birds Unlimited, the National Audubon Society, the American Bird Conservancy, or the National Wildlife Federation. Hopefully, these organizations will help bring attention to this problem, and help ensure that urban bird feeders do not unwittingly kill the birds they love.
Artificial Night Lighting and Birds
For over 100 years, observers have noted that artificial lighting caused problems for birds and other wildlife. In his classic text that some see as the start of the modern conservation movement (Mand and Nature, 1864), George Perkins Marsh reported on over 100 birds attracted and killed by the first lighting of the lighthouse on Cape Cod.

A conference convened by the Urban Wildlands Group in California addressed the ecological consequences of artificial night lighting (abstracts here). An accompanying bibliography of material on the problems of night lights and wildlife is online here. It documents effects of lighting on plants, aquatic invertebrates, terrestrial invertebrates, amphibians, sea turtles, other reptiles, fish, birds, and mammals.

For birds, city lights can disorient them during their migratory passage, as well as alter the daily rythms of resident birds. I've seen grackles feeding under the lights of a gas station in the middle of the night, and it is common to see nighthawks foraging over parking lot lights across North America.

Perhaps the most dangerous aspect of night lights, is their attraction for migratory birds. Lights can draw birds close to towers and skyscrapers, where they can be injured or killed by colliding with the structures. Many organizations are working to protect birds from these nocturnal dangers, including www.towerkill.com (extensive info, including links to USFWS towerkill bibliography) and The International Dark-Sky Association.

Additional good info can be found in news reports here, here, and here.

Proposed solutions include turning off skyscraper lights at night--see the work pioneered by the Toronto-based Fatal Light Awareness Program (FLAP)--and passing ordinances to restrict the types and number of outdoor light fixtures.

Saturday, March 13, 2004

Introduced Species
Urban areas often host exotic bird species that have been introduced deliberately or escaped from pet owners or bird collections. Monk Parakeets are one of the most commonly encountered exotic bird in American cities--they are establised in scattered cities including Chicago, Austin, New York, and Miami. Many other parrot species are common in southern California and Florida--with occasional birds reported throughout the country. Exotic waterfowl and other cage birds are also frequently released and observed flying free in U.S. cities.

While many people enjoy seeing exotic birds near their homes, birdwatchers often ignore them, since they are considered non-native and do not count on their personal life lists. However, in an attempt to find out how common exotic species are in urban areas, I am compiling a list of exotic species recorded in U.S. cities.

If you have seen an exotic or escaped bird in your city, email me the details: fergus at mail.utexas.edu.

Friday, March 12, 2004

Farming with the Wild
Yesterday I gave a talk about creating bird habitats in agricultural areas at a Hornsby Bend Bird Observatory workshop with Daniel Imhoff, executive director of Watershed Media and author of Farming with the Wild.

As cities sprawl out into rural areas, they increasingly draw upon distant agricultural areas for their food supply. The pesticide-ridden and soil-depleting industrial agriculture provides little by way of habitat needs for birds and other wildlife. Imhoff's book highlights alternative agricultural practices that provide habitat for birds and wildlife. Imhoff is also the co-founder of the Wild Farm Alliance, a group organized "to promote agriculture that helps to protect and restore wild Nature."

Thursday, March 04, 2004

Immigration, Sprawl, and Bird Conservation
Recent reports have highlighted the fact that population growth--with its attendent urban sprawl and habitat loss--is mostly due to immigration rather than human reproduction. The U.S. Census Bureau projects that the U.S. population will reach 403,687,000 by 2050. If current immigration continues at this pace, urban areas willl expand and local bird habitats will be under extreme development pressure. In 1999, the National Association of Home Builders reported that "the U.S. needs to construct between 1.3 and 1.5 million new housing units annually during the next decade simply to accommodate an anticipated 30 million increase in the nation’s population."

A considerable challenge for conservationists is to work with elected officials and non-governmental organizations to find ways to curb immigration and resource use in the United States, while working to improve living conditions globally in order to limit population movements.

Wednesday, March 03, 2004

Urban Birds Bibliography
The Rocky Mountain Bird Observatory (RMBO) near Brighton, Colorado, has an extensive (over 1100 entry) urban birds bibliography--a wealth of information for conservationists working in urban areas. RMBO was founded in 1988 "to address a bird conservation and related public education need in the western U.S." It is a leader in conservation efforts, and this bibliography is just one of their many valuable online resources. RMBO is a membership-based organization--membership info here.
Save Birds--Go Vegetarian
Recently, 57% of U.S. corn production has been used for livestock feed--that's 45 million (of 79 million total) acres. An additional 60 million acres are used for growing hay crops. If we were to reduce our meat consumption, we could free up over 100 million acres--over 164 thousand square miles, just larger than the state of California--of corn and hay cropland for birds and wildlife. Already, 34 million acres of American farmland are out of production--enrolled in the federal Conservation Reserve Program.

Mass vegetarian conversions are unlikely, so corn and hay farmers are safe. But urban bird enthusiasts should think about all that potential bird habitat needed to support their meat-heavy diets (215.9 lbs/year).

Tuesday, March 02, 2004

Harmony, FL--Example of Conservation Community
According to an upcoming paper presentation by Geographer Jennifer Wolch, Harmony, Florida "has gone further than any other major conservation community in attempting to implement an alternative philosophy toward human-animal and nature-society relations, and is thus offers insights into the limits to the conservation community model for reshaping human-animal relations in American cities."

Environmental programs at Harmony include a habitat management plan, full-time wildlife manager, and incorporates environmental guidelines into homeowner documents. Habitat preservation efforts include a 31 acre gopher tortoise habitat, a naturalistic golf course, and a two acre endangered orchid preserve. Only 30% of the 11,000 acre property will be developed.

Hopefully, as our cities inevitably grow, more developments like Harmony, FL will take wildlife into account.
Windows and Birds
An estimated 100 million to 1 billion birds die each year in North America after smacking into our lovely plate glass windows. Websites by the Humane Society of the United States, Wild Birds Unlimited, CNN, the Philadelphia Inquirer, and the National Wildlife magazine address this issue, which is probably the number one killer of birds in America.

For those wanting more than the popular media discussion of this problem, a classic paper on window kills by leading researcher Daniel Klem is online, and an earlier paper is here.

We all enjoy large windows and all the light they let into our homes and offices, but they are killing birds. The most promising possibility for addressing this issue is may be the film used for advertising on bus windows--which allows viewers inside to see out, but appears opaque on the outside. However, most fils are made of toxic PVC, a less toxic alternative should be developed. If inexpensive, attractive, and durable films can be developed, homeowners will be able to enjoy their views while ensuring the safety of their bird neighbors.

© Copyright 2004 Rob Fergus All rights reserved.