Sparrows with Wine-Colored Heads

House Finch (male) aka the "Hollywood Finch". This is a repost from August 2007.

The House Sparrow, (or "English Sparrow" as it is sometimes called) was first introduced to the U.S. in the 1850s and promoted to city officials across the East and Midwest as an effective form of pollution control -- sparrows were supposed to clean up the horse droppings littering America's streets.

Mayors, city councils and park officials heralded the release of sparrow colonies in much the same way they heralded the arrival of gas lights and indoor plumbing -- as a sign of America's coming of age. The House Sparrow was, quite literally, a kind of "equine catalytic converter" designed to make our increasingly crowded cities a cleaner place to live.

Within 20 years after its introduction, the booming population of House Sparrows in the U.S. was perceived to be having a negative impact on some native song bird populations, especially eastern bluebirds, tufted titmice, and various chickadees.

The friction between the immigrant and native birds was largely due to the aggressive nature of the House Sparrow which simply out-competed some native birds for housing and (to a lesser extent) food.

The rise of the House Sparrow created one of the more interesting environmental battles of the late 19th and early 20th Century. Dr. Thomas Mayo Brewer -- a great friend of John James Audubon and a co-author of the first modern catalog of American birds -- thought the House Sparrow was a wonderful and determined little bird and that, in time, it would prove to be one of America's favorites.



English Sparrow or House Sparrow, male and female

Opposing Dr. Brewer's love of the House Sparrow was Dr. Elliott Coues, whose "Key to North American Birds" remains one the most important works of American ornithology. Dr. Coues advocated an open war on House Sparrows, saying they were a peril to native birds. Dr. Coues described the House Sparrow as "sturdy little foreign vulgarians," and "animated manure machines ... without a redeeming quality."

This fray between naturalists was, believe it or not, a minor cause celebre, and was enjoined by the likes of Harriet Beecher Stowe (on the side of Brewer) and the very young Theodore Roosevelt (on the side of Coues).

In 1883, the American Ornithologists' Union (AOU), a newly formed organization made up of the most eminent men in the field of birding, resolved at their first meeting to decide "the eligibility or ineligibility of the European House Sparrow in America," i.e., should the sparrow be granted the right to be called a naturalized American bird?

In the end, the AOU concluded that the House Sparrow could not be admitted as an American species.

Despite this ruling, the House Sparrow eventually made its way into the AOU's "Check List of North American Birds," as an "introduced" species. By 1931 this distinction had evaporated, and the House Sparrow was added to the AOU check list without any quibbling or further notation.

The House Sparrow had, for all intents and purposes, been assimilated and was now a "North American Bird" (though, it should be said, it remains one of the few birds that can be trapped and exterminated without a license).

At about the same time that the American Ornithologists' Union was removing the asterisk next to the House Sparrow's name, House Sparrow populations began to decline as automobiles replaced horses in America's streets. Changes in farming practices further reduced the amount of grain spillage and horse manure available for avian gleaning. By the end of the 1940s, the first "house sparrow" reduction had occurred.

A second reduction in House Sparrow populations occurred in the 1970s and 1980s. The reason for this reduction was the rise of another bird in the eastern United States: the House Finch.

The House Finch is native to the American west. A pretty bird (it looks like a sparrow dipped up to its neck in red wine), House Finches were live-trapped in California after World War I and sold in eastern pet stores as "Hollywood Finches."

In 1940, however, the sale of domestic-caught wild songbirds was banned in the U.S. Caught with a small inventory of now illegal "Hollywood" Finches, a pet store in Long Island simply released them out the back door. From this modest and impromptu introduction sprang the millions of rose-headed finches we now have storming our bird feeders across the East.

The House Finch proved to be aggressive enough to "beat back" the House Sparrow, and a kind of detente now exists, with each bird helping to hold down the other's population.


Male and female House Finch

What about the birds that were once in decline due to competition with House Sparrows?

Ironically, they are doing fine and probably exist is numbers larger than they did in pre-Columbian time when the east was entirely in forest.

Edge-habitat-loving populations of Eastern Bluebirds, Tufted Titmice, and Chickadees are back up with the help of thousands of bluebird boxes constructed and placed in parks, on fence posts, and along nature trails by a generation of school children, boy scouts and dedicated birders.

As for Brewer -- the "winning" side of the house sparrow war -- "Brewer's Sparrow" is named after him. Ironically it is a native bird.

A bird is also named for Elliot Coues. Coues' Flycatcher, however, is mostly found in Mexico and Central America and can only be seen in the U.S. in the mountains of Arizona and New Mexico. Adding insult to injury, the AOU recently decided to change the name of Coues' Flycatcher to "Greater Peewee".

Clearly when you lose a war -- even a "sparrow war" -- your monuments do not last for long.
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Field Weeds: Poke Weed

American Goldfinch on mature pokeweed in late-June.


Poke Weed (often written as "pokeweed") is found from Maine to Minnesota and from Florida to Texas. It grows along roadsides and is an especially common weed in the hedgerows where we work our terriers.

The name Poke Weed comes from the Virginia Indian word for the plant -- "pokon" -- which in turn was derived from the Indian word "pak" which means blood. In pre-Colonial times "Pokon" was the term used for any red-juiced plant used as a stain or dye, and today Pokeweed is sometimes called "stain berry," poke berry," or "stain weed".

Though a mature pokeweed plant is the size of a small tree, the thick stems are hollow and very easy to cut. The berries are eaten by raccoon, possums and birds, but the roots are poisonous to pigs and other animals that try to root them up and eat them.

Pokeweed is usually confined to waste areas, but a tall mature plant is an indication that the soil has not been disturbed for three our four years, as it takes about that long for the roots to grow enough to support a full-grown plant which will stand about 7 feet tall or more.

Derivatives of the lowly pokeweed have been found to contain an antiviral protein that could be the most effective agent yet to inhibit HIV, the virus that causes AIDS. Pokeweed antiviral protein (PAP) inhibits HIV from replicating in human cells. PAP also inhibits replication of the herpes simplex virus, among others.
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A Wildlife Transmitter Beats an Arrow In the Neck

Re-posted from 2009.

Remember, when we were kids and people said the birds "flew south" for the winter?

Well, believe it or not, that was about all we knew for a lot of species.

Birds disappeared flying south in the Fall and came back, flying north, in the Spring. Where these birds went, exactly, and what they did when they got there, was a bit of a mystery.

Beginning in the 16th Century or so, some bird owners (pigeon fanciers and falconers mostly) began banding or ringing the legs of select birds to establish ownership.

The first record of a metal band attached to a bird's leg was in 1595, when one of Henry IV's banded Peregrine Falcons was lost in pursuit of a bustard in France. It showed up the next day in Malta, 900 miles away!

In the early 19th Century, the world began to get a glimpse into the scope of avian winter migrations, thanks to an arrow in the neck. Atlas Obscura tells the story:

Until the 19th century, the sudden annual disappearance of white storks each fall had been a profound mystery to European bird-watchers. Aristotle thought the storks went into hibernation with the other disappearing avian species, perhaps at the bottom of the sea. According to some fanciful accounts, “flocks of swallows were allegedly seen congregating in marshes until their accumulated weight bent the reeds into the water, submerging the birds, which apparently then settled down for a long winter’s nap.” A 1703 pamphlet titled “An Essay toward the Probable Solution of this Question: Whence come the Stork and the Turtledove, the Crane, and the Swallow, when they Know and Observe the Appointed Time of their Coming,” argued that the disappearing birds flew to the moon for the winter.



On May 21, 1822, a stunning piece of evidence came to light, which suggested a less extra-terrestrial, if no less wondrous, solution to the quandary of the disappearing birds. A white stork, shot on the Bothmer Estate near Mecklenburg, was discovered with an 80 cm long Central African spear embedded in its neck. The stork had flown the entire migratory journey from its equatorial wintering grounds in this impaled state. The Arrow-Stork, or Pfeilstorch, can now be found, stuffed, in the Zoological Collection of the University of Rostock. It is not alone. Since 1822, some 25 separate cases of pfeilstorches have been recorded.

What happened next? Well, quite a lot.

The 19th Century was a period of explosive scientific discovery, and people began to move beyond simple banding to establish ownership, to banding as a method of tracking birds across time and space.

Among the first to step forward in the name of Science was John James Audubon, who attached small ringlets of silver wire to the legs of a brood of Phoebes near Philadelphia so he could firmly establish that birds raised in one area were the same ones who later returned to nest in that same area.

In 1899, Hans Mortensen, a Danish school teacher, took the idea of bird-banding one step farther, and began banding wild birds with metal rings that had his name and address on them. It was Mortensen that invented the system of bird banding we use today, though it should be said that it was the Smithsonian Institution, here in Washington, D.C., which really popularized bird-banding, and made it an avenue of mainstream scientific inquiry.

For about 100 years, bird banding was how we tracked bird migrations around the world, and to tell the truth, it was not that great a system.

In a world of billions of birds, only a small fraction-of-a-fraction were ever going to be banded, and most of these were ducks or geese which had an obvious economic value. Smaller birds of no obvious value were much less likely to get banded, and only those birds shot or netted ever had any hope of having their identifications seen, much less returned to the proper data-keeper.

The result: until only a decade or so ago, we still had a very imperfect knowledge of where birds went when they "flew south" for the winter, and we knew even less about where they stopped and fed along the way.

The good news is that in the 1990s, the process of electronic miniaturization progressed to the point that scientists could begin to put transmitters on really large birds like hawks and cranes, and data from those transmitters could be uploaded to satellites. Today, the science of miniaturization has progressed to the point that it's possible to put a transmitter on a hummingbird -- even a dragonfly -- although we still need an airplane or car to follow on behind the smallest of transmitters.

It is hard to overstate how important electronic tracking is to wildlife management and protection. A small story, however, might give a clue.

Three of the very first miniature electronic tracking transmitters capable of linking up to a satellite were attached to Swainson's hawks back in 1994. Within a few days, two of the transmitters conked out, but the transmitter on the third bird retained power and showed the hawk traveled from southern Canada down the American Midwest into Mexico, Guatemala, Costa Rica, and past Ecuador into the Pampas region of Venezuela.

Scientists quickly scurried off to see if they could locate the animal.

What they found in Argentina was both amazing and disturbing.

The amazing part was that Swainson's hawks, which are solitary hunters in North America, assembled into large communal flocks of as many as 7,000 birds on their winter hunting grounds.

The disturbing part was that in Argentina Swainson's hawks lived on swarms of locust-like grasshoppers, which were being systematically poisoned by organo-phosphate pesticides.

The bug spray, in turn, was killing off the Swainson's hawks in droves.

As they drove into the area where the hawk's signal had last been heard from, scientists were alarmed to find thousands of hawks already dead under their roosts.

To make a long story short, that year 25 percent of all the Swainson's hawks in the world were killed by pesticides in Argentina -- a phenomenon that would never have been known had it not been for wildlife tracking telemetry.

The good news is that by switching to different types of pesticides, Argentina's farmers were able to sharply reduce grasshopper infestations while doing little serious harm to wildlife --a "win-win" for all sides.

As you might suspect, the brave new world of wildlife transmitters is still giving us a lot of new information, and great stories as well.

For example, one of fifteen Black-tailed Godwits released in the Friesland area of the Netherlands in 2009 arrived in Senegal West Africa three days later. The distance of 2,500 miles (4,000 kilometres), was covered by the bird in two days of nonstop flying.

Today, scientists are able to track bird populations around the globe, and load this information into graphics-based data bases so the general public can follow these epic migrations.

And it's not just birds that migrate, is it?

On every continent mammals, birds, fish and even insects migrate extraordinarily long distances.

It's not just Monarch butterflies that fly south for the winter for example -- it's a lot of dragonflies as well.

And it's not just herring and salmon that migrate out of oceans and up our rivers and streams -- it's perch and eels too. Out in the oceans, shark, tuna, whales, penguins, and sea turtles are swimming vast distances in never-ending seasonal circles, as they have for millions of years. On land we have long-distance migrations by caribou, bison, pronghorn antelope, elephant, wildebeest, and zebra.

How do the animals find their way? No one is quite sure.

No doubt there are a lot of factors that help guide them -- the position of the sun, wind, smell, temperature, sound, and visual landmarks, for starters. We know, for example, that when pigeons get closer to home, pigeons will actually follow roadways, same as you and I.

Migrations at night, when most birds fly really long distances, however, may be due to an internal magnetic compass that is hard-wired into the brain and working off of a bit of superoxide.

And it's not just birds that have this bit of electro-chemistry firing off in their brain -- bats do too.

And if bats (mammals) have electro-magnetic compasses in their brain, why not fish?

The main benefit of wildlife transmitters, of course, is that by tracking animals -- so many of which move about only at night -- we are better able to protect vital wildlife and ancient migration corridors.

That's a benefit for everyone -- the wildlife, hunters, and Mother Nature included.

On a more personal level, of course, the tremendous strides made in wildlife transmitters over the last two decades, have been an enormous benefit for those of us who engage in highly-skilled primitive hunting with dogs, hawks, falcons, and ferrets.

Yes, hawks and falcons are still lost rather routinely, but falconry transmitters and Yaggi locators offer some hope of recovery.

In the world of terriers and ferrets, the development of small low-frequency transmitters means long layups underground and long and dangerous digs are less frequent than they once were.

Even houndsmen and pet owners have benefited, thanks to tracking collars to serve their various needs.

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Want to read another amazing bird migration story? Check out A Shearwater's Endless Summer from a March 2007 post to this blog.
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Maladaptive Pigeons at the Hand of Man

The Rock Dove or Rock Pigeon, from which all domestic pigeons derive.

Dogs are not the only animals that have been selected for function and dysfunction at the hand of man.

For more than a thousand years, pigeons have been bred to express an amazing amount of genetic variation, from beautiful to grotesque, and from whimsical to functional.

The litany of pigeon breeds is truly jaw-dropping and reflects a global fraternity of breeders.

There are Aachen Lacquer Shield Owl pigeons, Aachen Pouter pigeons, and Aargau Peak Crested pigeons.

There is the Absy Egyptian Swift, the Afghan Sherazi, African Owl pigeon, Agaran Boinije, Ahmar Gohzar, Alpine Swift, Altenburger Trumpeter, American Bohemian Pouter, American Flying Baldhead, American Flying Flight, American Flying Tumbler, American Giant Homer, American Giant Rumbler, and the American Giant Runt (love that name!).

We have the Anatolian Ringbeater, the American Strasser, Anbary Asmar Egyptian Swift, Ancient Tumbler, Antwerp Pigeon, Antwerp Smerle, Arabian Trumpeter, Arad Barred Highflier, Archangel, Armenian Tumbler, and Asiatic Crack Tumbler.

We have Australian Saddleback Tumbler, the Barb, Bavarian Pouter, Beak-Crested Jacobin, Belgian Ringbeater, and the Berlin Medium Face Tumbler (which also comes in Long Face and Short Face varieties).

We have the Bernburg pigeon, the Berne Half Beak, Berne Peak Crested, Bernhardin Magpie, Birmingham Roller, and the Blondinette.

We have the Blue Tumbler of Cluj, Bohemian Pouter, the Bohmentaub, the Bokhara Trumpeter, the Bolk Egyptian Swift, Boston Blue Tumbler, Bremen Tumbler, British Show Racer, and Brunner Pouter.

We have the Bucharest Ciung Highflier, the Bucharest Show Tumbler, the Buda Grizzle, Budapest Short Face Tumbler, and the Budapest Highflier (to say nothing of the Budapest Muffed Tumbler and Budapest Muffled Stork).

We have the Cassel Tumbler, the Catalonian Head and Neck Tumbler, the Central Asiatic Roller, Chinese Nasal Tuft, Chinese Owl, Clean Legged Fullhead, Clean Legged Spot Swallow, Coburg Lark, Colillano Pouter and Cologne Tumbler.

We have the Czech Ice Pouter, Czech Muffed Tumbler, Czech Trumpeter, the Dragoon, and the Damascene.

We have the Danish Suabian, Danish Tumbler, the Danzig Highflyer, the Escompadissa Tumbler, the Dewlap, the Donek, the Double Crested Priest, the Duchess, the Egyptian Swift, the Eichbuhl, the Elster Pouter, and the Elster Purzler, to say nothing of the English Carrier, English Fantail, English Longface Muff Tumbler, English Magpie, and English Owl.

We have the Exhibition Flying Tippler, the Fat Shan Blue, Felegyhazer Tumbler, and the Fish Eye Roller.

We have the Florentine pigeon, Flying Oriental Roller, Flying Saddle Homer, Flying Tippler, Fork-Tailed pigeon, Franconian Heart Magpie, Franconian Toy Self, and the Franconian Velvet Shield, to say nothing of the French Bagdad, French Mondain, Frillback, Gaditano Pouter, Galaţi roller, German Beak-Crested, the German Modena, German Nun, and German Shield Owl.

We have the Ghent Cropper, Giant American Crest, Giant Mallorquina Runt, Giant Show Runt, the Gier pigeon, the Gorguero Pouter, Groninger Slenke, the Hamburg Sticken, Hana Pouter, Hanover Tumbler, Helmet pigeon, Hindi Fantail, Hollander pigeon, Hungarian Buga Pigeon, the Hungarian Giant House Pigeon, Hungarian Giant Pouter, and the Hungarian Short.

We have the Huppé Picard, the Hyacinth pigeon, Ice pigeon, Indian Fantail, Indian Gola, Indian Mondain, Iran Roller, Italian Owl Jacobin, and the Jiennense Pouterm as well as the Indian Fantasy pigeon (love that name!),

There is the Kaluga Turmani pigeon, the Karakand Fantail, Karakandy Egyptian Swift, Kazan Tumbler, Kelebek, Kiev Tumbler, King pigeon, Kiskunfelegyhaza Tumbler, Kojook Egyptian Swift, Konigsberg Moorhead, Lucerne Gold Collar, and the Lebanon pigeon.

There is the Lucerne Gold Collar, the black Magpie, Macedonian Turbit, Majorcan Bort Runt, Maltese pigeon, Mariola pigeon, Martham pigeon, and the Memel Highflier.

We have the Mesawed Egyptian Swift, Micholaiyvski Shield Tumbler, Miniature American Crested, Mookee, Montauben, Moravian White Head, Moscat, Moscovite Tumbler, Moulter, New York Danish Flying Tumbler, Norwegian Tumbler, Norwich Cropper, and the Novi Sad Short Face Tumbler (what a name!).

We have the Nun pigeon, Nuremberg Lark, Old Dutch Capuchine, Old Fashioned Oriental Frill, Old German Cropper, Old German Owl, Ostrava Bagdad, Pakistani Highflier, Parlor Roller, Pheasant Pigeon, and the Ukrainian Skycutter (love that name!).

We have the Pomeranian Show Crest, Posen Colored Head Tumbler, Poster pigeon, Prague Medium Face Tumbler, Oriental Frill, Quet Roller, Racing Homer, Rhine Ringbeater, Roller Pigeon, Romanian Argintiu Tumbler, Romanian Blind Tumbler, Romanian Blue Barred Whitetail, Romanian Naked-Neck Tumbler, Russian Martini, Saddle Homer, Saint Louis Arch Crested Fantail, Saxon Breast pigeon, Saxon Monk, Saxon Stork, and Silky Fantail.

We have the Single Crested Priest, South German Charcoal Lark, Spaniard pigeon, Spanish Flamenca Runt, Spanish Frillback Bagadette, Spanish Owl Pouter, and Spanish Thief Pouter.

We have the Sverdlovsk blue-gray mottle-headed pigeon, Swiss Crescent, Swiss Mondain, Syrian Bagdad, Syrian Coop Tumbler, Syrian Swift pigeon, Syrian Turbiteen, Texan Pioneer, Thai Fantail, Thai Laugher, Thuringian Breast Pigeon, Thuringian Spot, Thuringian Wingpigeon, Tiger Swallow, Tippler, and the Transylvanian Double-Crested Tumbler (love that name!).

We have the Ural Striped Maned pigeon, the Tung Koon Paak, Valencian Giant Tenant pigeon, Valencian Magany Homer, Vogtland pigeon, Volga Russian Tumbler, Warsaw Schmetterling, the West of England Tumbler and the Zurich White Tail.

And yes, this is just a partial list!





As I noted some years back, there is a breed of pigeon called a "roller" where flocks go into a kind of synchronized neurological fit causing them to roll over and tumble in mid-air -- the kind of activity that tends to attract hawks. Talk about maladaptive!

In addition to rollers, there are racing or homing pigeons which look very much like natural rock doves (i.e. wild pigeons), but which may have a little more speed and slightly better orienteering skills.




Of course, as with dogs, many of these breeds are only slighty different variations from others of a very similar type, while others look suspiciously like odd-looking versions of the common feral form you might see in any city park, while still others look like diseased mutants.

But isn't that true of dog breeds as well?!



Some of the pigeons that have been crafted by the hand of man are truely beautiful and fly very well, while others are bizarre looking and fly less successfully.

In the bizarre catagory is the Blue Pouter, pictured below, which is an ornamental breed with long legs, an extruded body, and an amazing inflatable crop.




There are quite a few types of Pouters, and the function of one type, the "Horseman" Pouter is to serve as a "thief" bird. It turns out that a swollen crop is a bit of a turn on to female pigeons, and so female pigeons can sometimes be seduced to follow the Horseman Pouter back to his coop.



Charles Darwin was quick to notice the amazing varieties of livestock being produced by breeders in his day, and he was especially attentive to chicken and pigeon breeders as he himself had first noticed wide variation from an intermediate type when observing finches on the Galapagos Islands.

When Darwin came back to Britain in 1836, he began to correspond with dog, chicken, sheep, cattle and pigeon breeders from around the world as he worked out his theories of speciation through natural selection.

In 1855, he built his own pigeon loft and began raising a wide variety of pigeons himself.

For the rest of that story I recommend a lengthy tour through the excellent web site, Darwin's Pigeons.





A final note: the beautiful pigeon illustrations shown here are the work of Gary Romig, and are for sale at his web site.

They are redone versions of illustrations which first appeared in Robert Fulton's The Illustrated Book of Pigeons, published in 1878. A companion volume, by Lewis Wright, was called The Illustrated Book of Poultry.
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From Near Extinction to Common Pest in 50 Years

It is hard to describe the destruction of American wildlife between 1850 and 1900.

By 1850 all the Elk had been shot out in the East, the Forest Bison pushed into complete extinction, the Wolf extirpated from everywhere in the East but the Maine woods.

Between 1850 and 1900 the great herds of Plains Bison were cut down to within a few hundred animals of extinction, White Tail Deer and Wild Turkey were virtually extirpated along most of the Atlantic seaboard, geese and ducks of every type were slaughtered in dizzying numbers by shrapnel fired from cannon used by market hunters, and the beaver had simply vanished from every state East of Ohio. The Carolina Parakeet and Passenger Pigeon were gone, as was the Eskimo Curlew -- birds which once numbered in the millions.

The turn around in American wildlife populations began with passage of the Lacey Act in 1907, which banned market hunting.

A critical turn around in the fortunes of wild geese and duck occurred in 1935 when live decoys -- wild birds that had been trapped and made flightless with pinned or clipped wings -- was made illegal.

It looked like the ban on live decoys had come too late for some species, however. One of those species was the Giant Canada Goose which was thought to be extinct -- or nearly extinct -- in the wild.

The good news is that while there were almost no wild Canada Geese left, captive decoy goose populations still existed. With the 1935 ban on the use of decoy geese, most of these animals were released into marshes and onto ponds. Unable to fly, many of these animals quickly fell prey to fox and dogs, but some managed to grow back their feathers or live long enough to reproduce.

During World War II and into the 1950s, the descendants of once-captive Giant Canada Geese slowly multiplied in remote marshes and isolated ponds. While a natural recovery seemed to be occurring, these descendants of once-captive geese were largely non-migratory since, after three or four generations in captivity prior to 1935, they no longer had any "lead geese" to show them the way North.

In the 1960s the Giant Canada Geese population remained so low across the U.S. that it was considered extirpated in most states and near-extinct in the wild. In order to prevent extinction, a systematic effort was made to captive-raise Giant Canada Geese and introduce small flocks back into areas where they had once existed.

The introduction of Canada Geese was a phenomenal success. Absent hunting and disease, small flocks of Canada Geese grew by 10 to 20 percent percent a year -- a population doubling time of just 3 to 7 years time.

In a relatively short period of time, states saw a phenomenal growth in their Giant Canada Goose populations. Ohio, to cite on example, began with just 20 captive-raised birds in 1956, but by 2002 had a population of over 140,000 birds. Today almost all the geese you see in the Eastern U.S,. and Midwest are Giant Canada Geese.

The U.S. Fish and Wildlife Service estimates the current resident Giant Canada Goose population of the U.S. at 4 million birds and growing rapidly, with a small number of truly migratory Giant Canada Geese still found in the mid-Atlantic flyway.

Giant Canada Geese have also been introduced into other parts of the world, most notably Europe, where they are also thriving.

The "goose problem" today is not extinction but an over-abundance of geese in areas where heavy population densities may inconvenience golfers and cause eutrophication of farm ponds.

A boom in geese populations, however is not too bad a problem as problems go, and it has certainly been a benefit for fox which frequently raid Canada Goose nests in order to feed rapidly growing kits.

The rise of Canada Geese has also created a boom in sport hunting which now pumps hundreds of millions of dollars a year into rural economies. No one has benefited more from the demise of commercial market hunting than the sport hunter.

With the demise of market hunting, and with the assistance of capable wildlife managers, the Giant Canada Goose has returned, as has the wild turkey, the beaver, the bison, the elk, white tail deer, alligator and even the wolf. Truly, these are the good old days.



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Eggs Past and Eggs Future

The picture above is a shot of a Victorian-era museum collection of wild bird eggs. These kinds of fantastic collections began around the time of Darwin, with egg collection an outgrowth of egg collections gathered for scientific purposes and a spontaneous outgrowth of curiosity about the diversity of the natural world coupled with the kind of relative (and conspicuous) wealth that allows people to travel to collect, buy and display curiosities that otherwise have no useful and practical purpose.

Bird egg collecting proved to be such a fad that collection of rare bird eggs threatened to tip certain rare birds over the abyss into extinction. In 1954, the Wild Birds Protection Act in the U.K. made it illegal to posses or own any wild birds' eggs taken since that time, and today it is illegal to sell any wild bird's egg, irrespective of their age -- a fact that is now true in the U.S. as well.

Ironically, old bird egg collections are an important resource for scientists studying bird biology, enabling them to track the rise of pesticides and other contaminants in the food chain.




The eggs, above, are a couple of odd ones I had around the house.

The dark one is an emu, the largest eggs is an ostrich, and the other two are chicken eggs that I had for breakfast.

I include the chickens eggs to show the scale of the other two, but also to show the diversity of what eggs can look like. Egg identification, without benefit of a nest or provenance, can be pretty hard, as bird eggs can change shape to some extent. Coloration and markings may also shift from bird to bird as well. Egg identification is an in-egg-zact science, especially where speciation is not complete (a surprisingly large number of birds) and the number of look-alike eggs are quite numbing.

Another small thought: We have pushed a lot of birds over the edge to extinction and near-extinction, but I am always struck by the fact that we never give credit to the fact that a lot of species (or what we would call species if they were wild) are now being created by man.

Chickens alone present a startling array of expressed diversity, to say nothing of cattle, roses, corn, broccoli, etc. We are already creating new species of birds (falcon and parrot hybrids are examples) and fish (hybrid trout, salmon, pan fish, etc.). to say nothing of the many odd things being done with recombinant DNA to make animals and plants grow larger, be more resistant to disease, and ship better.

We stand in the door of one of the largest booms in species creation ever, and yet when was the last time anyone gave that idea a nod? And yet, take a look at the two chicken eggs, pictured above. Would any birder claim these eggs were from the same species?

Warbler Politics: How Birds Made Two Presidents

Prothonotary warbler.  This post is mostly recycled from 2007.

The latest news out of Texas this campaign season (June 2016) is that the the U.S. Fish and Wildlife Service has denied a petition to delist the golden-cheeked warbler, a 5-inch, black-and-white bird with a bright yellow face.

This news comes to my door as large number of warblers arrive from the south, delayed a few days perhaps by the rain and cold we have had in the last month.

The weather seems to change every day now, with cold and warm fronts crashing into each other, and the resulting squalls bringing flocks of small birds north on the winds.

The warblers are returning to Virginia in droves. They are more visible now than they will be later on when the foliage will obscure them high up in the trees. You have to look carefully among the mixed flocks of returning chickadees, titmice, and nuthatches to find the warblers, but they are there.

Warblers are very important birds, as they are the primary insect eaters in North America's woods. The bad news is that most warblers are in rapid decline over vast portions of the U.S. due to forest fragmentation which is occuring both in the U.S. and overseas where "our" warblers spend the winter. I have written a bit about that in the past.

Something I have not written about before is how warblers have shaped presidential politics. In fact, it is not too much to say that "warbler controversies" have led directly to two presidents being elected to office.

The first president to have his early career shaped by a warbler was Richard Nixon.

Back in 1948, Whittaker Chambers, a senior editor at Time magazine, and a former Communist spy turned government informer, accused Alger Hiss of being a spy for the communists in the mid-1930s.

Chambers was not exactly a credible witness; he had very little documentation to back up his charges and he admitted at the Hiss trial that he had repeatedly committed perjury on other occasions. Inititially it was not clear he had even met Hiss, much less knew him well.

Chambers claimed he did know Hiss, and backed it up by noting that Hiss was a bird-watcher who was very proud that he had seen a prothonotary warbler near Glenn Echo Park just outside of Washington, D.C.

In cross examination of Hiss before the House Committee on Un-American Activities (HUAC), a young Congressman by the name of Richard Nixon asked a seemingly innocent question: "What hobbies, if any, do you have, Mr. Hiss?"

Hiss answered that his hobbies were "tennis and amateur ornithology." Congressman John McDowell then jumped in an asked Hiss whether he had ever seen a prothonotary warbler?

Hiss walked right into the trap, responding that he had -- "right here on the Potomac."

Slam -- the trap had been tripped. Committee members were now convinced it was Hiss who was lying, not Chambers. After a series of trials, Hiss was sentenced to prison for 5 years based on very sketchy (and still controversial) evidence.

As for Nixon, he managed to use the Hiss affair to propel himself from the U.S. House of Representatives into the Senate, and from the Senate into the Vice Presidency under President Dwight Eisenhower.

The rest, as they say, is history.

The saga was was not quite over, however. In 1952, not quite content to let his 15 minutes of fame pass him by, Whittaker Chambers published his autobiography, which was entitled Witness. Ronald Reagan later credited this book with transforming him from a New Deal Democrat into a conservative Republican.

While shilling for General Electric in the 1950s and early 60s, Reagan made frequent references to Whittaker Chambers in his speeches, and on March 26, 1984 -- 23 years after Chambers had died -- Reagan posthumously gave Whittaker Chambers the nation's highest honor, the Medal of Freedom.

Probably no one has ever deserved it less.



Golden-cheeked warbler.


Another President propelled into office on the wings of a warbler was George W. Bush.

In June of 1994, a memo from the U.S. Fish & Wildlife Service was leaked. The memo outlined a tentative plan to declare hundreds of thousands of acres across 33 counties in Texas hill country as being "critical habitat" for the endangered Golden-cheeked Warbler.

It was feared that, if implemented, "the plan" would have made it virtually impossible to bulldoze Ashe Juniper off of the surrounding hills -- a necessity if those hills were to be turned into nice new housing developments with grass lawns and underground sprinkler systems.

Massive opposition to the informal Fish & Wildlife Service proposal sprang up overnight, with school auditoriums quickly filled to capacity by ranchers, developers, and property owners who were led to believe that the draft proposal was soon going to be made into law overnight, and that it would impact almost all private property.

In fact, the proposal was a mere internal memo within the agency (no rules or regulations had been written or circulated, and no draft Environmental Impact Statement had been initiated), and the designation of critical habitat directly affected only actions that were to be federally funded or authorized, not privately-held lands.

George W. Bush was not a stickler for the facts (then or now) and he jumped on the wave of misinformation circulating through Texas in order to fan the flames of discontent. Positioning himself as a champion of the property rights movement, Bush hammered on the "federal land grab" even after Interior Secretary Bruce Babbitt had disavowed the leaked memo and Texas Governor Ann Richards also voiced her strong opposition.

Richards, of course, was too late. Bush campaign operatives -- including Karl Rove -- had already framed the issue and associated Ann Richards with it -- never mind the facts, or her true position.

Texas being Texas, and modern political discourse being what it is, people believed the Bush Campaign's spin.

In the end, due in no small part to the warbler controversy, George W. Bush was elected Governor of Texas, which he later used as a stepping-stone to the White House.

And the rest, as they say, is history, written in debt, blood, and destruction
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The Archeology of Hunting

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Humans have spent most of their time on earth hunting, and it is not entirely surprising that there is at least some archaeological evidence of the activity.

In North American before Columbus, there were no metal tools or horses. Hunting was done entirely on foot, and hides and meat were hauled off by humans and dogs pulling travois skids.

In some rare locations a very efficient form of hunting was accomplished by running bison herds off of cliffs or "Buffalo Jumps" -- a fact we know today only because of the enormous piles of bison bones at the base of these cliffs, and the related stone tools and campfires.

Archaeologists have discovered that drive lines were made to direct herds of bison to the jumps. The drive lines consisted of rows of rock piles known as "dead men," arranged like a wide funnel that started up to 8 miles away from the jump site. The funnel gradually narrowed toward the jump end. Hunters hiding behind the "dead men" rock piles would spring out and wave robes and shout in order to frighten the animals and keep them inside the funnel and headed in a stampede towards the jump where they would tumble down, breaking legs and necks as they fell.

In Europe, large Deer Parks were created during the Middle Ages as a way of setting off land for aristocratic hunters and managing sustainable game populations for food. The edges of these parks were often edged by massive earthwork moats and mounds which, in turn, were topped by wooden fences. The moats were on the inside and prevented the deer from getting a foothold or a run-up to the top of the mound which was constructed from the earth taken from the moat excavation. Many UK locations with "Park" in their name are, in fact, old Deer Parks and with careful observation in some locations, you can see parts of remnant ditches and mounds.

As with the ancient Buffalo Jumps, hunting in deer parks was accomplished by driving game through funnel fences to archers who were positioned on the ground or in tree stands.

In the 14th Century there were over 3,000 deer parks in England occupying around 650,000 acres of land (over 1,000 squre miles). These deer parks were managed for wild game and for wood. In the larger deer parks streams were dammed to make small lakes and ponds for fishing and ice making.

Most of the large deer parks fell into disrepair in late Medieval times as the feudal system collapsed under the weight of the Plague, and a new form of hunting -- coursing with horses and dogs -- was imported from France.

Another archaeological remnant of hunting to be found in Europe are rabbit warrens. The rabbit is not naive to the UK -- it was introduced (probably from Spain) by the Romans shortly after the First Century AD. Across the UK ancient artificial warrens can be found to this day. These warrens are called "pillow mounds" or buries and are flat topped, 10 to 20 metres long, 5 to 10 metres wide, and up to a metre high, sometimes surrounded by a shallow ditch. About 2,000 of these ancient buries survive in England, and in some of them artificial runs are covered with stone slabs. Some of the very largest artificial warrens had professional staff (a warrener) and buildings.


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Duck and Fish Ponds provide additional archaeological evidence of hunting and angling across the globe. Many of these ponds have artificial islands on them created as spots where ducks and geese can breed free of predators. While the waters of these ponds were stocked with fish, the ponds were often designed with "dog-leg" lagoons, or a narrows on one end, where ducks and geese could be driven and easily netted.

The United States is a very young nation, and much of the Western U.S. was nearly devoid of people only 150 years ago. That said, Americans are industrious and the construction of small ponds and large lakes for water storage and ice-making naturally led to increased still-water angling and duck hunting.

In short order, some people began construction of dams specifically to increase angling and hunting opportunities. One such dam was constructed on the South Fork River near Johnstown, Pennsylvania. The dam itself was a massive earthen affair constructed by the South Fork Fishing and Hunting Club which counted among its 66 wealthy Pittsburgh residents Andrew Carnegie, Henry Clay Frick, Andrew W. Mellon, and Philander Knox.

At the time of its construction, the South Fork Dam was one of the largest in the world, but it was not well constructed. A flawed design was made worse when the Fishing and Hunting Club put screens across the safety spillway to prevent fish from washing over the dam during heavy rains. The spillway screens were constantly clogged with debris, but despite many warnings about the safety of the dam, the rich aristocrats who owned the hunting club continued on, business as usual.

On May 31, 1889, after a period of heavy rain, the dam finally gave way sending a 45-foot-tall wall of muddy water racing down the Conemaugh Valley. More than 2,209 lives were lost and 27,000 people were made homeless -- one of the greatest single losses of human life in the history of the United States.



Civilian Conservation Corps Tree Planters, 1939


The most notable period of U.S. construction for wildlife benefits began with the advent of the Civilian Conservation Corps (CCC) in 1936. The CCC was created as a Depression-era jobs program which eventually put millions of young men to work on reforestation, soil erosion, flood prevention, and trail construction projects across the United States..

The Corps was badly needed -- America had ruined scores of millions of acres of once-forested lands during the rip-rape-and-ruin robber baron era that lasted from 1850-1900.

Massive tracts of forest in our eastern mountains had been swept clean of trees, and streams were choked with silt. Wildlife had been shot out to the point that deer were nearly extinct, all beaver were gone, and ducks and geese were a rarity in areas where they had once been in dense numbers.

The Lacey act of 1907 and the Weeks Act of 1911 were important for protecting wildlife and conserving land, but wild America had been so severely hammered by unrestrained greed that it was to clear that it would take millions of hours of human labor and a lot of time to begin to set things right.

President Franklin Delano Roosevelt started the ball rolling in 1934 with the appointment of Committee on Wild-Life Restoration whose mandate was to prepare a plan to restore America's dwindling wildlife populations. Among its members were the great wildlife manager Aldo Leopold, and cartoonist Ding Darling.

The Wild-Life Committee recommended far-reaching changes to improve habitat for waterfowl, upland game, mammals, and song birds, including the acquisition of millions of acres of additional sub-marginal lands for habitat improvement, and appropriations of $50 million to restore these lands to some semblance of their natural self.

It did not take a genius to see that the Wildlife Restoration Plan and the Civilian Conservation Corps were ideal partners, and under the tutelage of Darling -- a man who later went on to create the Federal Duck Stamp Program and found the National Wildlife Federation -- significant gains were made in record time.

By the end of 1942, national wildlife refuges, national forests, and other public lands across the U.S. had been improved by CCC workers who constructed dams, dikes and fish hatcheries, planted millions of trees to stabilize stream banks and cover over ruined land, and erected numerous buildings, fire towers, telephone lines and support facilities for camping grounds, and improved backcountry-access for hunters and hikers.

Civilian Conservation Corps construction projects remain a significant addition to our National Parks, National Forests and Wildlife Refuge System to this day, and are too-little heralded part of our American wildlife heritage.
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Hunting the Foreigners

Greg Mousely minking, June 2003

The latest news from Scientific American is that non-native wildlife in Europe wreaks $16 billion a year in damage.

Not said:  Foreign fauna provides considerable sport in the UK and across Europe.

Among the mammal introductions to the U.K.:

• The Brown or Norwegian Rat, which arrived around 1720.
• The Grey Squirrel which arrived around 1870.
• The Sika Deer which arrived around 1870.
• The Chinese Muntjac Deer which arrived around 1940.
• The Mink, which was released around 1950.
• The Rabbit which was introduced by the Romans (or perhaps the Normans) around 1000.
• Fallow Deer which were introduced by the Normans around 1200.
• The Muskrat which was introduced around 1927.
• The Red-necked Wallaby which was introduced around 1940 (and is uncommon)
• The Coypu or Nutria, which was introduced around 1944 and wiped out by 1988.

In the U.S., most of the animals we commonly hunt and fish are native, with the exception of pheasants, some species of grouse, brown trout, and (of course) almost all the red fox.

The brown or "Norwegian" rat provides terrier sport for some folks, as does the nutria in areas where better quarry is scarce on the ground.

The raccoon can be thought of as a recently introduced species west of Ohio, and north of the Southern Great Lakes.

Many of our most common urban birds are foreign, including starlings, english sparrows, and the common pigeon (aka the Rock Dove).

Our hedgerow are choked with foreign invasive plant species, such as honeysuckle, kudzu and, of course, multiflora rose. This last plant was widely planted after the Great Depression in order to slow erosion in the South, but it also naturalized from abandoned gardens (multiflora rose is the root stock that most of our ornamental roses are grafted on to).

The dandelion is an immigrant ("dent de lion" means "teeth of the lion" and refers to the serrated edges of the leaves) as is Tumble Weed (aka Russian thistle) and, of course, the wild horse and mule.

Our forests, of course, have been decimated by invasive species from the chestnut blight which wiped out our most magnificent Eastern timber and mast-food tree, to dogwood blight which is now doing the same to our most beautiful native flowering tree.

The gypsy moth was introduced to this country by a Frenchman trying to start a silkworm industry, while the newly introduced ash borer beetle may decimate one of our very best sources of clear hardwood.

All in all, relatively few introduced mammals have "made it" in America, as compared to the U.K., and many of the plants, bugs, birds and pestilents that have made it over here have had an entirely negative impact.
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The Rise of Muliflora Rose

When out digging the dogs, it is not uncommon to find a sette under a thick break of multiflora rose, with perhaps a few broken strands of barbed wire snaking along the ground right next to the hole.

In that little picture is a story.

Multiflora rose originated in Japan and was imported to Europe around 1862 to serve as a root stock for "rambling" roses.

Rambling roses became a craze with the creation of "Turners Crimson Rambler" in 1893, and this craze lasted for about 30 years until the modern, repeat blooming, large-flowered climbing roses were created.

The first multiflora roses to "go native" in the U.S. were rambling roses that originate during the rose craze of the very early 20th Century. In truth, these feral roses were not much of a problem.

The problem started in the 1930s and extended into the early 1960s as the U.S. Department of Agriculture and various State highway departments promoted multiflora rose as a "cure-all" for many public and farm landscaping problems.

In truth, multiflora rose did seem to be a good solution for a lot of difficult areas. Multiflora was cheap, easy to propagate from cuttings, and was rampant with vigor. Long, arching and pliable canes with thorns were perfect for shielding car lights from oncoming traffic, discouraging humans from entering fields or crossing roadways, and keeping cattle out of riparian areas.

Rose roots seemed to thrive in a large variety of soils, tolerated both drought and wet reasonably well, and they did a commendable job of stabilizing creek banks and slowing erosion on slopes. Rose hips were also eaten by a wide variety of song birds and animals, providing a needed food source in winter.

The U.S. Department of Agriculture and its various state analogues vigorously promoted multiflora rose as a low-cost alternative to barbed wire. Barbed wire had made its way East several generations earlier after first being established in the West.

Unlike western wire, which was typically strung from post to post, eastern wire was often strung from existing trees around the edges of woods, creeks and fields. In time, these the trees grew and absorbed the wire into their trunk. Embedded wire was difficult to remove and made the trees worthless as timber since wire and nails wrecked commercial saw blades and had the potential of turning a chainsaw into a lethal weapon.

Like so many good ideas, the promotion of multiflora rose has unintended consequences. A mature multiflora rose bush can put out half a million seeds a year, and these seeds are easily spread by birds and can live in the soil for 10 years or more.

Farmers found that getting rid of a rose hedge required riping it out with a bulldozer and then plowing and mowing the areas multiple times a year for several years in order to destroy the existing root and seed stock in the soil.

The good news with multiflora rose is that has truly been a boon to wildlife. Rose hips are consumed by robins, grouse, cedar wax wings, pheasants, wild turkeys, fox, chipmunks, white-tailed deer, possums, coyotes, black bears, beavers, rabbits and raccoons. Thick rose breaks provide shelter for deer and bear, as well as groundhogs, possums, fox, rabbits, and raccoons. Rose hedges along stream banks have worked to keep cattle and horses out of riparian areas, resulting in less erosion, cleaner water, and excellent denning sites for raccoons.

Next time you find yourself digging a hole in the middle of a multiflora rose bush with broken barbed wire snaking along the ground, remember that these stabbing obstacles are, in a very real sense, a significant player in the vigorous return of wildlife we see in in the Eastern U.S. today. Though they may be the enemy of the moment, they are the long-term friends of terrier work.

A Battle of Peregrine vs. Starling

Guess who wins?
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Are the Cat Birds Getting Eaten by the Dog Sharks?

Are the Cat Birds getting eaten by the Dog Sharks? 

Of course they are. As the American Bird Conservancy notes:

Researchers at Dauphin Island Sea Lab in Alabama, who have been conducting a two year study focusing on the diets of Tiger Sharks in the Gulf of Mexico, have made a surprising discovery: not only are the sharks feeding on fish and other marine organisms, they are also feeding on land-based birds, such as woodpeckers, tanagers, meadowlarks, catbirds, kingbirds, and swallows.

“We were not expecting to see this. It certainly prompts a series of questions, the most obvious being, how does a land bird end up in the water as food for sharks?

What's to blame? One theory is that lighted offshore oil and gas platforms attract the birds which then get trapped in a cone of light, circling around until they get exhausted and fall out of the sky or crash into the platform. There are about 6,000 oil and gas platforms in the Gulf of Mexico.
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Predator Fear, Alone, Results in Fewer Birds

Fear of meso-predators, and fear alone, results in fewer successful clutches according to a paper by Liana Zanette entitled "Perceived Predation Risk Reduces the Number of Offspring Songbirds Produce per Year" that appears in the December 8th edition of Science. 
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The Missing Birds of Rock Creek Park

OvenBird

This was written in 2003 for a major environmental organization.

The decline of neotropical migrant song birds in the U.S. was first noticed by birders in Washington, D.C.'s Rock Creek Park, a small federally-protected enclave nestled along a stream bed in Washington, D.C., just 15 miles from Fairfax County.

Breeding Bird Surveys from 1947 through the 1970s, revealed that the yellow-billed cuckoo and yellow-throated vireo -- as well as the northern parula, black-and-white warbler, Kentucky warbler, and hooded warbler -- were disappearing. Six other migrant song birds -- Eastern wood-pewees, Acadian flycatchers, wood thrushes, red-eyed vireos, ovenbirds, and scarlet tanagers -- had declined by more than 50 percent.

What was going on?


Evidence from Overseas

Domestic forest destruction was ruled out, as Rock Creek Park had suffered no substantial encroachment in decades.

An analysis of radar images, done in the early 1980s, however, showed only half as many birds were flying to the U.S. from Mexico's Yucatan as had been migrating just 20 years earlier. Clearly, some part of what was happening to "our" birds was happening overseas. Experts theorized that much of the song bird decline, now being documented across the U.S., was due to forest destruction in Central and South America.

In fact, forest destruction in Central America was proceeding at a very rapid pace, driven in no small part by truly sobering rates of human population growth. In the Peten region of Guatemala, for example, 77% of the original forest cover still existed as recently as 1977. By 1980, however, that number had fallen to 42% and by 1989 just 29 percent of the original forest cover was gone. Scientists now believe as little as 10% of the forest may be left by 2025.


Evidence from the U.S.

By the late 1990s, however, scientists began to realize that forest destruction in Central and South America did not tell all of the story. Analysis of migrant song bird populations at the national level showed that birds loss was not evenly distributed across the U.S.

While most migrant song birds are experiencing clear negative trends east of the Mississippi River, and along the thin coastal strip of the West Coast, neotropical migrants seem to be doing fairly well on large tracts of forested land in the West.

An overlay of neotropical migrant song bird decline and a map of federally protected lands, showed a fascinating pattern: migrant song birds were not in general decline in our national parks, our national forests, or on lands managed by the U.S. Department of Interior's Bureau of Land Management. Migrant song birds were in general decline in the east and in the Midwest, however, where changing agricultural practices and increasing levels of forest fragmentation seemed to be having a real impact.

Scientists looking for clues to song bird loss in Rock Creek Park began to look at the forested areas immediately surrounding the suburbs of Washington, DC, and what they found was pretty startling. Between 1980 and 1995, Fairfax County saw 69 percent of its forests converted to homes and businesses.

While scientists had been puzzling over bird loss in Rock Creek Park, just 15 miles away, Fairfax County's forests had been vanishing under asphalt at an astonishing rate.

Scientists now recognize that these once-vibrant suburban forests were probably the principal "home" of many of the birds that had once been seen in Rock Creek Park. Rock Creek had merely served as way-station between larger forest blocks that once ringed the Washington, DC area.

As new roads and light rail systems continue to be built in the suburbs of Virginia and Maryland, more and more forests are falling to farms and more and more farms are falling to freeways and subdivisions.

Once large blocks of unbroken forest are being shattered into increasingly smaller fragments, allowing such meso-predators as crows, jays, raccoons, possums, feral cats and fox to prey on once-secure migrant song bird nests. In addition, increasingly fragmented forests have enabled the brown-headed cow bird to colonize areas they once would have found unattractive.

Cowbirds nest at the edge of forests and feed in farms fields and pastures. Though native to North America, the brown-headed cowbird was once confined to the forest edges of Midwestern prairies where they fed in grasslands grazed by roaming bison. Today, however, because of widespread forest fragmentation, parasitic cowbirds can be found all across the United States.

The brown-headed cowbird is a parasitic nester, which is to say it builds no nests of its own, but instead lays its eggs in the nests of other birds -- most frequently in the open, cup-shaped nests of neotropical migrants. A single cowbird may lay as many as 80 eggs in a breeding season - one or two eggs per songbird nest. Because cowbird chicks hatch earlier, and are much larger than the offspring of migrant songbirds, they are able to out compete songbird chicks for food, and often simply push them out of the nest altogether.

In the end, a single cowbird may prevent 20 to 30 warblers, finches and vireos from raising their young. If the bird species has a short nesting period, it may not be able to hatch out a second brood that year, in which case that species may fall off rapidly in that area over a relatively short period of time.


Yellow-throated Vireo


More Trouble Ahead?

While a great deal of population-driven environmental damage has already occurred in the suburbs of Virginia, more population growth lies ahead. Fairfax County's population continues to grow rapidly, most of it driven by a combination of internal domestic migration (military and government families coming to support a burgeoning government and high-tech corridor) and international migration.

Fairfax County may be a demographic "canary in a coal mine" signaling where the rest of America may be headed in terms of land use patterns and population growth. With U.S. population growing by more than 3 million people a year, and suburban sprawl gobbling up more than 500,000 acres of forest and farmland every year, the pace of habitat fragmentation is likely to increase rapidly in the years ahead.

Under the Census Bureau's middle-series projection, which assumes that current U.S. immigration and fertility levels will stay about the same, the population of the U.S. will increase by 120 million people over the course of the next 50 years. About 63 percent of this future population growth will be due to immigrants and the children of immigrants that have not yet arrived in the U.S. -- the remaining 37 percent of population growth will be driven by demographic momentum as current U.S. residents move to complete their families.

One hundred and twenty million people is a very large population to add to the U.S. over the course of the next 50 years. To put this number into perspective, this is a population equal to the current populations of California, Oregon, Washington, Idaho, Colorado, Montana, Arizona, Nevada, New Mexico, Texas, Wyoming, Utah, North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, Minnesota, Wisconsin, Iowa, Missouri, Arkansas, and Louisiana combined.

In addition to sprawl directly driven by population growth, the U.S. can expect to see increased forest fragmentation due to more and more folks moving farther and farther out into the countryside, abetted by high-speed internet hookups, satellite television, and light rail systems feeding into an ever-expanding network of four, six and eight lane highways.

As Canadian real estate agent Ozzie Jurock noted in an article for The Vancouver Sun (June 30, 2001),

"People throughout North America are on the move. Population growth in smaller towns is exploding. Californians move to Oregon and Arizona, New Yorkers joke at the rain but moved to Washington. The ski resorts and lakes are teeming with 'former' city slickers clutching cash and the hope for the elusive 'better quality of life."

Even as population growth continues apace in the U.S., the population of Central America continues to grow. Over the course of the next 50 years, Central America and Mexico combined are expected to add 90 million people to their populations -- a 65% percent increase in population.


Why the Fairfax Bird Loss Story is Important

Bird population data are such a robust metric of general environmental health that in the United Kingdom they are used as an official indicator of environmental sustainability.

A broad decline in many wild bird populations in the Western Hemisphere may be an indication that a broad decline in environmental quality is occurring across much of the region.

In the case of neotropical song birds, population-driven habitat decline along the entire migration flyway -- including the United States -- has had a serious impact on U.S. song bird numbers. The decline of songbird species in the U.S. is a powerful reminder that population pressures beyond our borders really do "come home to roost" and that reducing the rates of population growth at home, and abroad, is a real and serious "back yard" environmental issue.

Ironically, even as many bird populations are in decline, the number of Americans interested in birds is on the rise. The National Survey on Recreation and the Environment found that over 71 million Americans are recreational birders, up 250 percent from 1982, making birding the fastest-growing outdoor activity in the U.S.


Black and White Warbler
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Bird Species Decline in the U.S

In large parts of the U.S., over half of our songbird species are in decline. Scientists say habitat destruction is largely to blame.

Across the United States, more than 250 species of neotropical migratory birds fly south for the winter.

Beginning in the early 1970s, scientists began to notice that many species seemed to be in decline

What was going on?

Scientists have concluded that the decline of neotropical migratory song birds in the United States is closely linked to four issues closely linked to human population growth and habitat destruction:

• Tropical Forest Destruction
  The population of Latin America and the Caribbean has doubled in the last 35 years, and with it has come unprecedented destruction of tropical rainforests. As populations have exploded, more landless peasants have colonized forest areas and cleared vegetation, with slash-and-burn cycles becoming progressively shorter. At the same time, logging over wide areas and the rapid expansion of commercial farming has accelerated the disappearance of forests and fueled the rapid destruction of once-lush bird habitat. In the Peten region of Guatemala, for example, 77 percent of the land was covered in dense forest in 1960. By 1990, that number had fallen to just 29 percent.
  
  
• Pesticide Use Overseas
  Neotropical migratory birds are being killed by the heavy use of insecticides, herbicides and fungicides, which are used to boost crop productivity to feed increasing numbers of people in the developing world. In some cases, birds are poisoned outright by chemical application, or by consuming grain and insects that have been sprayed. In other cases, the pesticides accumulate and concentrate within the birds, resulting in deformed chicks or eggshells that are so thin they break before hatching.
  
  
• Suburban Sprawl and Forest Fragmentation
  As the population of the United States has grown from 76 million in 1900 to over 280 million today, cities and suburbs have sprawled outward. Fairfax, Virginia, for example, a suburb of Washington, D.C., saw 69 percent of its forest converted to homes and businesses between 1980 and 1995. As human populations have risen, and forests have fallen, primary predators such as wolves, bobcats, and cougars have been wiped out, while the ecological niche of meso-predators such as feral cats, raccoons, possums and foxes has expanded. The result has been massive predation of Neotropical songbirds, which tend to nest in the open and near the ground rather than in tree cavities or higher up in the forest canopy.
  
  With forest fragmentation has come an invasion of native and non-native birds that compete with deep-forest species for food and nesting sites. One example is the brown-headed cowbird. Cowbirds were once confined to the forest edges of mid-western prairies where they fed in grasslands grazed by roaming bison. Today, however, because of widespread forest fragmentation, parasitic cowbirds can be found all across the United States. A single cowbird may lay as many as 20 eggs in a breeding season - one or two eggs per songbird nest. Because Neotropical migrants tend to build open cup-shaped nests, and raise only a single brood a year, they are particularly susceptible to cowbird parasitism.
  
  
• Intensive U.S. Farming Practices
  As American farmers make increasingly intensive use of their lands, bird populations suffer. Post-to-post cultivation has wiped out edge-row thickets where many songbirds used to nest, while many farmers now cut hay three times a year where they used to cut just once. The result is that hedgerow and ground-nesting birds like the northern bobwhite, the eastern meadowlark, the vesper sparrow, and the grasshopper sparrow are in rapid decline.
  
  

Cowbirds, Mesopredators, & Grass Nesting Birds

The National Audubon Society's Christmas bird count is a pretty good organizing tool, but a little weak on science, since it is mostly counting bird-feeder birds that are not in too much danger of loss.

So what birds are in decline in the U.S.? Mostly neo-tropical migrants and grassland-nesting birds. More on neo-tropical migrants tomorrow. For now, let's look at grassland birds.

U.S. populations of Henslow's Sparrow, Cassin's Sparrow, Grasshopper Sparrow, Field Sparrow, Savannah Sparrow, and Vesper Sparrow exist in numbers only a fraction of what they did in the 1850s when the tall grass prairies had yet to fall under the plow.

Over the course of the last 20 years alone, the Breeding Bird survey has enumerated a very rapid decline in these birds that seems unrelated to loss of land across the U.S. Other grassland birds also seem to be in decline, especially such sparrow-like birds such as the Bobolink, the Dicksissel, and the Western Meadowlark (the state bird of Kansas, Montana, Nebraska, North Dakota, Oregon and Wyoming).

What is going on? The short answer is industrial agriculture.

As human population numbers have increased in the U.S. and across the world, more and more pressure has been put on America's farm land -- the source of 15% of the world's cereal production.

The good news is that record crops are being produced despite the fact that less and less land is being put under the plow.

The bad news is that this increased production has required more automation, less fence-row cover, and more intensive management of farm habitat than ever before.

A good example of what is going on can be seen by taking a look at America's hayfields. While 40 years ago a hay field might have been harvested once a year, most hayfields are cut three times a year now, thanks to automation. The second and third hay harvests typically occur just as grassland birds are breeding.

The good news is that while we are farming our most productive lands more intensively, we are putting a lot of marginal farm land into a Conservation Reserve Program (CRP) started in 1982.

The CRP has worked to take more than 32 million acres of farmland out of production in order to slow top soil loss and exhaustion, and to provide habitat for native plants and animals. CRP lands now total more than 50,000 square miles across the United States, and make up vast stretches of some prairie states.

Unfortunately, despite the extensive acreage put into the CRP program, it has not been enough to reverse the decline of some grassland bird species.

One problem is that much of the land in the CRP program is in relatively small blocks, often bordered by working farms. This "edge" habitat is perfect for deer, fox, raccoon, raptors, pheasant, grouse and turkey, but it is not always conducive to the successful breeding of grassland birds, many of which only do well in very large blocks of prairie devoid of trees.

In fact, because the population of medium-size predators such as fox, raccoon, possum and hawks is high in edge habitat, grassland nest mortality of small grass-nesting birds is often unnaturally high in small-acreage CRP locations.

In addition, the tree cover provided by old farm windbreaks and shelterbelts provides a near-perfect habitat for the brown-headed cowbird.

The brown-headed cowbirds is a brood parasite species which lays its eggs in nests of other birds and leaves them for the host bird to raise.

Because cowbird eggs hatch a few days before those of their hosts, the larger cowbird chick is able to push out the eggs and chicks of the host bird, thereby winning all the food resources for itself.

The destructive capacity of the brown-headed cowbird is hard to overestimate: a single female can destroy the clutches of 20 or more song birds in a single season.

Would I advocate shooting a cowbird? In a minute.

In fact, in some areas the only way to get native bird species back up to acceptable levels is with Larsen Traps designed to catch cowbirds. To learn how to build a cowbird trap (a good project for a boy scout !) click here.
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