Wednesday, August 30, 2006

Bald Eagle in Baltimore

An immature bald eagle caused a stir in Baltimore today by landing on a city sidewalk in a residential neighorhood. It walked around on the sidewalk and the street for an hour and a half. Residents assumed that something was wrong with it and had called the Maryland Department of Natural Resources to send a wildlife rescuer. But before this could be arranged, the eagle flew away.

The Sun article provides two possible explanations from local wildlife experts. One focused on a possible injury.
"Why the heck it would stand around on Bolton Street for an hour? Who knows?" said Glenn Therres, associate director of the Wildlife and Heritage Service at the Maryland Department of Natural Resources. "I don't know if it flew into something and was dazed for a while. It could have been injured, but the fact that it flew away suggests the injury might not have been that severe."

At any given time, there are about 2,000 bald eagles in Maryland, Therres said. The eagles nest along the shores of tidal waters in the region, but the birds - which were upgraded to threatened from endangered in recent years - rarely if ever hang out on city sidewalks, Therres said.

"There are a lot of them floating around, acting like teenagers and juveniles, just kind of looking for a good place to eat or to socialize with other birds their own age," Therres said. "A wooded shoreline on the Potomac or Susquehanna [rivers], but not normally in an urban neighborhood in Baltimore City."
A second explanation is that it was merely resting.
David Curson, director of bird conservation for the Maryland and District of Columbia branch of the National Audubon Society, said the bird might have eaten a large catch of fish and was too stuffed and lazy to move.

"It's difficult to explain, but one possibility is, it may have eaten a large meal," Curson said. "Sometimes, when a bird like that eats a large meal like that it gets weighed down. But without knowing all the facts and not having seen the bird myself, it's difficult to be sure."

Monday, August 28, 2006

Katrina Updates

Now that we have arrived at the one-year anniversary of Hurricane Katrina's landfall on the Gulf Coast, newspaper articles are considering the lingering damage done by the storm. Many refuges along the coast were hard-hit and are struggling to recover. Part of the problem is that the storm washed salt water into fresh water ecosystems and killed vegetation that could not stand the salinity. The waters also dumped all forms of trash and toxic waste into the refuges. Cleaning and restoring the marshes will take years and substantial investment.

The refuges damaged along the coast are important for both breeding and migratory birds. Twelve Important Bird Areas lay in the direct path of the storm. The long-term effects of the storm on the birds that used those areas will not be known until more research is done. In the short term, many birds seem to have abandoned their traditional nesting habitats. Among the species with reduced nesting colonies include Brown Pelicans, several species of herons, Black Skimmers, and Sandhill Cranes.

On a lighter note, Judith Toups reports that in the weeks after Hurricane Katrina, her yard was filled with ruby-throated hummingbirds.

Monday, August 21, 2006

Bachman's Warbler?

The Cornell Lab of Ornithology has posted video of a possible Bachman's Warbler on its website. This film was shot in Cuba in January 2002. After recording the bird, the photographer used field guides to identify it as a female Bachman's Warbler. Cornell's ornithologists reviewed the video and deemed it inconclusive. They have asked for comments from experienced observers.

What do you think of the video?

For comparison, here is a painting of male and female Bachman's Warblers by John James Audubon.

Sunday, August 20, 2006

New Rules For Canada Goose Management

The U.S. Fish and Wildlife Service is making it easier to kill Canada Geese without a permit. Its new rules apply to airports, landowners, and state wildlife officials and are intended to reduce the population of resident geese along the Atlantic Flyway, where the number of geese increases at a rate of about 2 percent per year. Large numbers of resident geese have resulted in safety problems at airports, conflicts with golf courses and other private landowners, and obstacles for habitat restoration.

The new regulatory program consists of three components. The first creates control and depredation orders for airports, landowners, agricultural producers and public health officials that are designed to address resident Canada goose depredation and damage while managing conflict. This component will allow take of resident Canada geese without a federal permit provided certain reporting and monitoring requirements are fulfilled.

The second component consists of expanded hunting methods and opportunities and is designed to increase the sport harvest of resident Canada geese. Under this component, States could choose to expand shooting hours and allow hunters the use of electronic calls and unplugged shotguns during a portion of early September resident Canada goose seasons.

The third component consists of a new regulation authorizing the Director to implement a resident Canada goose population control program, or "management take". Management take is defined as a special management action that is needed to reduce certain wildlife populations when traditional and otherwise authorized management measures are unsuccessful, not feasible, or not applicable in preventing injury to property, agricultural crops, public health, and other interests. Under Management Take, the take of resident Canada geese outside the existing sport hunting seasons (September 1 to March 10) would be authorized and would enable States to authorize a harvest of resident Canada geese between August 1 and August 31. Management take would be available to States in the Atlantic, Mississippi, and Central Flyways following the first full operational year of the other new regulations.

In the DC area, there are between 500 and 600 resident geese living in the Anacostia watershed.

Limits on Menhaden Catch

Last week we reported that Osprey in the Chesapeake Bay area may be suffering due to the decline in Atlantic Menhaden. The fish, which are crucial to the diets of Osprey and other birds, have been in decline for the past two decades. At the end of the week, the Atlantic States Marine Fisheries Commission acted on the problem:
ARLINGTON, Va. A regional fisheries commission has agreed to cap the commercial catch of menhaden in the Chesapeake Bay.That cap is intended to give scientists time to assess the health of the tiny but important bait fish.

Meeting in Arlington, the Atlantic States Marine Fisheries Commission voted today to set the cap through 2010....

The annual catch will be limited to 109-thousand-20 metric tons, with flexibility for years when the catch is up or down.

Tuesday, August 15, 2006

John Bull Dies at 92

John L. Bull, an ornithologist based in New York City, died this past Friday. Among other accomplishments, he wrote the first guide to the birds of New York State, and co-authored the bird guide for the eastern region in the National Audubon Society's series of photographic field guides.

A research assistant at the American Museum of Natural History, Mr. Bull led popular birding tours of Long Island and Central Park in the 1960’s and 70’s and meticulously kept track of the species and the state of their habitat.

In 1964, he wrote a book, “Birds of the New York Area,” intended for would-be birders living in the suburbs of New Jersey, Long Island and Connecticut and for those in Manhattan itself, a prime birding destination. It covered the mourning doves of Central Park to the horned grebes off Montauk Point.

Mr. Bull later expanded his reach and wrote about all of the 410 bird species that had been recorded throughout New York State. That book, “Birds of New York State,” which was published in 1974, was the first exhaustive survey of the subject in 60 years. Another researcher, E.H. Eaton, had recorded only 366 bird species in 1914.

In Mr. Bull’s book, he noted the new or increased counts of species usually found at more southerly latitudes — like the snowy egret — and suggested that a milder climate might be at work in changing migration patterns.

Joel L. Cracraft, curator in charge of the ornithology department at the American Museum of Natural History, said the guidebook was “a first-rate state bird book.”

“At the time,” Dr. Cracraft said, “there was not a high-quality and professional account of the great diversity of New York’s species and their distributions.”

Declining Menhaden May Threaten Osprey Reproduction

The Osprey population of the Chesapeake Bay region has been adversely affected by the decline of Menhaden, a small fish, along the Atlantic coast. The Chesapeake has one of the largest breeding populations of Osprey anywhere, with close to 4,000 pairs. Within the last decade, researchers have found increasing numbers of malnourished and dying chicks. They argue that this is because the Ospreys' preferred food, Menhaden, has declined sharply over the past two decades.
Menhaden filter the bay's waters by eating the microscopic plants and animals that consume dissolved oxygen needed by other aquatic life. In turn, they're a primary food source for sport fish, such as striped bass, bluefish and weakfish, and seabirds, including loons, gulls and gannets.

Ongoing scientific research focuses mostly on the ecological role that menhaden fill underwater. Broader public awareness has centered on the fish's importance to recreational anglers. But, like striped bass, ospreys favor meals of menhaden over other fish.

"Of everything we know about the bay, this is one of the fundamental food chains: Ospreys eat menhaden," said Paul Spitzer, a Maryland ecologist who specializes in birds.

One study found that menhaden made up 70 percent of the diet of ospreys nesting on Mobjack Bay off the coasts of Gloucester and Mathews counties.

Other studies done along the Atlantic coast have turned up similar results.

Menhaden swim in large schools that skim the water's surface, and they move straight ahead rather than dart around like other fish.

That makes them a perfect prey for circling ospreys, as well as Omega Protein's spotter planes, which radio a school's coordinates to waiting boats.

A fishery commission is considering imposing limits on harvesting of Menhaden while more research is done to determine the causes of the fish's decline.

Sunday, August 13, 2006

Trip Report: Delaware Marshes

Black Skimmer / Photo via NaturePicsOnline

Four Audubon members set out from Washington on August 12 to look for late summer birds. The day was perfect for birding: high around 80, clear, and breezy. We set our sights on Bombay Hook National Wildlife Refuge. This refuge, which sits at the edge of Delaware Bay, consists of close to 16,000 acres of tidal salt marsh, together with several freshwater impoundments and upland hardwood forest. The diversity of habitats makes it possible to find many species of birds, especially during migration. Bombay Hook is a fine place to bird in any season, but is at its best during spring and fall migration. For a Washington-based birder, the attraction of this refuge is the ability to see many species of shorebirds that are hard to find at inland locations.


Wednesday, August 09, 2006

Field Trip This Saturday

Join DC Audubon on Saturday, August 12, for its annual late summer field trip to Bombay Hook National Wildlife Refuge and the Delaware Marshes. During this trip we hope to see herons, shorebirds, and terns as they end their breeding season and begin their journey south. In addition, the marshes and woods of the refuge boast many resident species. One can see purple martins and blue grosbeaks near the visitor center, and other Eastern Shore specialties like seaside sparrow and marsh wren breed along the boardwalk trail. On our May field trip this year, we saw over 100 species in and around Bombay Hook. We may not reach that total on this trip, but we should see many beautiful and interesting birds during our trip through the refuge.

For a more recent account of Bombay Hook by a local birder, see here.

For directions and RSVP information, see our webpage. (It is important that you contact the trip leader as soon as possible if you intend to come.)

Sooty Shearwaters Have Longest Migration

According to new research, sooty shearwaters make the longest known migration. The birds travel close to 40,000 miles each year from their breeding grounds around New Zealand to their wintering grounds in the North Pacific. That way, the birds can take advantage of the summer in both the northern and southern hemispheres. Scientists were able to track this route using electronic tracking tags.
Between January and March 2005, 33 birds at two breeding colonies in New Zealand were fitted with tags weighing 6g, allowing researchers to track their journey.

In the autumn of that year, 20 of the tags were recovered when the birds returned to their burrows at the breeding grounds; 19 of the devices had successfully recorded the bird's movements.

Data showed that some birds travelled up to 910km (565 miles) in a day, and dived to depths of 68m in their search for food.
One interesting result of the study is that individual birds do not travel around the circumference of the Pacific, as previously thought. Instead they travel quickly to one of the winter feeding grounds, located near California, Alaska, and Japan, and then return quickly to their breeding grounds at the end of the southern winter. Below is a map showing the travels of the 19 shearwaters with working tags.

Blue = Breeding season activity
Yellow = Flight north
Orange = Wintering activity and flight south

Saturday, August 05, 2006

Tracking Bees, Bugs and the Birds That Love Them

(From NPR) For decades now, ecologists have been attaching radio transmitters to the bodies of large animals: whales, bears, elephants, condors and eagles for starters. What these scientists haven't done is stick the same devices onto animals like song birds and big insects, those migratory flying things that sometimes mow down crops and spread diseases.

For eight years now, Wikelski's been the leader of a group of scientists who do collect those data points, with the help of radio transmitters no bigger than a baby's thumbnail. These scientists are known as "microtrackers" and for now they're few and far between.

But Wikelski's work is changing that by forcing ornithologists to change the way they think about migration. His first microtracking studies started nearly a decade ago when Wikelski captured groups of mid-Western thrush and glued extremely sophisticated radio transmitters to the bellies of these birds.

"The transmitters recorded heartbeat, breathing, wing beats and location," he said. "Once every second, they sent all this information out in concentrated bursts."

Wikelski says we know very little about how small animals migrate. Scientists would find out where birds are born and where they die. They would discover where birds are making pit stops on their trips home. And they would be able to track locust swarms and birds that could carry avian flu across international boundaries.

Wikelski turned the focus of his research to flying insects. With the help of prominent entomologists like Mike May of Rutgers University, he's been attaching even smaller transmitters to the backs and bellies of insects. Listen and read more on NPR.

Tuesday, August 01, 2006

Pesticide Action Alert

The following came from the American Bird Conservancy (via Birderblog).
URGENT - We have 24 Hours to Stop the Most Deadly Pesticide to Birds

The U.S. Environmental Protection Agency (EPA) is poised to make a decision on whether to ban the bird-killing pesticide, carbofuran. This is the most deadly pesticide to birds currently being used in the United States. It is more toxic than DDT. A single drop is enough to kill a bird.

We have just learned that because of pressure from the manufacturer, FMC corporation, the EPA may make the wrong decision and elect to keep this pesticide on the market. We have 24 hours to counteract the industry pressure. We need your help.

We ask you to email, CCing telling the EPA to ban carbofuran now because of its danger to birds, other wildlife, and people. Your email can be brief. Use the talking points provided below to help. What is important is that you tell them in your own words that you do not want carbofuran to be used in the United States. Alternatives exist that are equally effective and not deadly to birds. There is no reason to keep carbofuran registered.

Please send your email before 5pm Wednesday August 2, 2006!

Alternatively you can fax your comments to 202-564-0512.

Thank you for taking this emergency action on behalf of birds and wildlife,

George Fenwick
President, American Bird Conservancy

We provide the following talking points to help you let EPA know why this chemical must be banned:
  • All legal uses of carbofuran kill birds resulting in potential violations of the Migratory Bird Treaty Act (MBTA) every time it is applied. Farmers are placed in jeopardy of violating the MBTA whenever carbofuran is used, even if
    they follow the label directions.
  • Carbofuran is very toxic to people. Human risk assessments have been done three times and they show greater risks to farm workers each time they are refined. These studies indicate that carbofuran is too dangerous to use.
  • Carbofuran is so toxic it kills all the beneficial insects as well as pests with the result that integrated pest management cannot be done.
  • Carbofuran is so toxic that no crop rotation can be performed for ten months after application. This eliminates the possibility of crop rotation as a tool for reducing insect damage to crops.
  • Alternative chemicals exist for all crops except artichokes. Many alternatives exist for corn. Only a very small percentage of corn produced in the U.S. uses carbofuran now because of its environmental effects and safety issues.
  • New insecticides have been developed for rice, cotton, corn, and other crops specifically to replace carbofuran. Most of these are reduced risk chemicals presenting much less bird, wildlife, and human health risks.
  • Transgenic corn has been developed specifically for resistance to corn rootworm and European corn borer, further reducing the need for conventional pesticides.
  • The United States is a world leader in pesticide regulation. Cancellation of carbofuran will send a strong message to Latin America, Canada, and Mexico about the dangers of this pesticide. This will help save birds in those countries when they phase out carbofuran. Canceling the tolerances of pesticide residues on foods will immediately limit the use of carbofuran in all countries that export to the US.

Helping Birds in a Summer Heat Wave

During heat waves like the current week's, many birds suffer from heat illness, just like humans. To keep cool, birds will seek shade, pant, hold their wings away from their body, and bathe. You can help the birds around your home deal with the heat by taking a few steps.
  • Provide sources of water for drinking and bathing. Remember that smaller birds prefer shallow water. Some ideas for providing water are here. Empty and refresh the water to keep it clean and free of mosquito larvae.
  • Clean hummingbird feeders and refresh their sugar water regularly. Very warm conditions can lead to the growth of dangerous bacteria and fungi.
  • Keep any seed feeders clean of refuse where germs could breed and spread.

Remember to keep yourself safe by following the CDC's heat illness guidelines.