Monday, September 7, 2009

The Hazards to Urban Birds: Death and the City

This Great Blue Heron died by hanging after becoming entangled in discarded fishing line.

Birds are miraculous creatures. The product of millions of years of evolution, they have survived as a species through various adaptations to changes in their environment due to natural causes. Life is harsh, but birds do thrive if left alone. But they have one huge obstacle: human activity. Humans have survival and life needs, too. But many are also selfish and self-serving, and they often do not take nature into consideration before they act.

Everyone immediately focuses on global warming now as one of the chief causes of bird declines and to some extent that is true. But what gets lost are the insidious dangers, the ones that are overlooked because they are so pervasive that most people don’t even see them anymore, let alone see them as a problem.

The earliest threats to birds were quite obvious. The ladies hat fashions at the turn of the century nearly caused the extinction of Great Blue Herons. The heron rookeries in Florida were being decimated by hunters who were killing them for their beautiful plumage, which was in turn sold to millinery operations in the North, until T. Gilbert Pearson brought it to the public’s attention (and founded the first incarnation of the Audubon movement).

Another lethal (and incredibly cruel) activity was the annual Christmas bird hunt, where shooters went out and killed every bird they could find in one day. It is hard to fathom the type of person that would find this sporting or even fun, but cruelty seems to be an unfortunate characteristic of America’s psyche.

The 1950s ushered in the age of plastics and pesticides; a lethal one-two punch that has been plaguing birds ever since. These seemingly innocuous, yet perfidious products have caused much death and near extinction of birds in modern times.

Plastic six-pack rings were one of the first really serious threats to birds, especially gulls and waterfowl, when they became ensnared and strangled in them. Since then, plastic, whether as bags or micro trash, are killing birds by the millions. National Geographic even did a feature story not long ago on how albatross are picking up everything from plastic bottle caps to disposable lighters, ingesting them and feeding them to their young. Both adults and chicks are dying from malnutrition as a result. The small careless gesture of flipping that bottle cap or empty disposable lighter into the gutter rather than the trash is wrecking havoc in the lives of birds thousands of miles offshore.

In the 1960s, the first serious urban sprawl began to claim natural habitats for human homes. Hills were graded, fences erected, cement poured—all with reckless disregard for wildlife. This continues today--with devastating results--as we have lately seen in Rossmoore, CA. Residents there badgered the U.S. Fish and Wildlife Service into issuing a permit for the killing of Acorn Woodpeckers that had been using homes for granaries after the native oak trees were cut down to build a retirement community.

Another component of urban sprawl is the planting of greenscape and landscaping that is not carefully chosen. Developers often choose fast-growing, exotic trees that have problematic roots, and messy leaf and fruit fall that residents cannot live with. The result is ill-timed and careless tree and hedge trimming during the spring and summer nesting season, which results in many bird deaths and loss of suitable nesting sites. Audubon has just published its first “Guidelines for Tree and Shrub Trimming and Removal” in hopes of mitigating some of this preventable destruction.

The latest danger that has come to the attention of Los Angeles Audubon is discarded monofilament fishing line. Monofilament fishing line, though it may look harmless, is deadly to birds. It is designed to be invisible to fish, but it is also invisible to birds. Entanglements with fishing line have led to the deaths of thousands of birds, as well as the amputation of limbs of many others. Shorebirds and waterfowl are particularly susceptible to entanglement with fishing line when they forage for food. Birds may also become impaled with hooks, and if they are hooked in the neck or swallow the hook it will prevent them from feeding and they will die of starvation.

Several recent incidents have raised the awareness of this problem. The first was on March 18 and involved me personally when I found a Royal Tern along the Ballona Creek bike path. The bird was standing just off the path, shaking its head involuntarily. A woman nearby said that she and her boyfriend had removed a hook from its neck (kind, but not the smartest thing to try on your own) and some fishing line that was wound around its neck. Eleanor Osgood rescued the bird, but it died that night.

A second incident was on March 30, reported in the LA County Birds listserve. David Chadsey of Etiwanda reported seeing a “gull tied to a white buoy directly out from the little green pier. It appeared to be caught in a long loop of fishing line and was struggling to get airborne.” This lucky bird was saved by the lifeguards at the lake, who went out in their patrol boat and rescued the gull.

The third incident, reported by Judith Raskin of Echo Park, involved the near-strangulation of a Double-crested Cormorant on April 10. Barbara Jarvik found the “hapless cormorant dangling from fishing line in a eucalyptus tree.” The LAFD was called and fortunately was able to cut the bird down before it strangled to death. This bird likely survived; others are not so lucky.

Many people are surprised to hear that it takes fishing line 600 years to break down in the environment. That's six times longer than tin cans and batteries, 17 times longer than fishing nets, and 40 times longer than plastic bags. This makes fishing line a real danger that does not go away, making clean-up and recycling of this lethal waste material a critical issue.

All these hazards to birds due to human activity are preventable. With education and raising the awareness of the public, these threats to birds can be managed and even eliminated. Birds deserve as much of a chance to survive as human beings do. We at Audubon believe in being good neighbors and sharing the environment with birds rather than usurping it from them.

If you would like to become involved in our conservation efforts, we would welcome all the help we can get. These problems won’t go away on their own; it takes people to undo the problems created by people. So do something nice for the birds for a change and volunteer on one of Los Angeles Audubon’s conservation projects today!

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