Courtesy Twin Cities NaturalistCheck out this week's Phenology Roundup where professional naturalist Kirk Mona of Twin Cities Naturalist discusses what's been seen around the Twin Cities area in the last week. Phenology is the science of the seasons. It looks at how and when nature changes according to seasonal climatic conditions.
Courtesy Wikimedia CommonsBirds are known to spread plant seeds by eating them and dispersing them in their droppings. But scientists in Japan have found that some species of snails can also survive the trip through the avian digestive tract. Researchers at Tohoku University discovered that about 15 percent of the tiny snails (Tornatellides boeningi) eaten by the Japanese White-eye (Zosterops japonicus) survived the trip through the birds gut and were dispersed in its droppings. If this can happen within an island ecology, it probably means snails and other invertebrates could be dispersed over longer distances and from one island to another or from one isolated region to another. It certainly raises new questions of species radiation. The study was done on the island of Hahajima, located 600 miles south of Tokyo, and in the lab, and the findings published in the Journal of Biogeography. (In researching this I came across this related study done by T. D. A. Cockerell 90 years ago!)
Check out the live streaming video of a bald eagle's nest in Decorah, Iowa courtesy the Raptor Resource Project. When I was watching it earlier it was windy and one of the parental eagles was trying its best to shield the three chicks and make them comfortable. At night, the camera watches the nest in infrared light so the stream is live around the clock. The site includes a chat room (open from 8am to 8pm) and also links to archived footage of the eggs hatching in early April.
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So there's this rumor running around that wind turbines kill birds, and it's true--they do. But are turbines the greatest threat birds face?
Courtesy Lionel Allorge
A number of things kill birds in the wild--predators (including cats and other birds), pollution, cars, windows, tall buildings, airplanes, and habitat loss are some examples. In suburban areas, cats may be the single greatest bird predator. A recent study in the suburbs of Washington, D.C. showed that cats were responsible for nearly 37% of gray catbird deaths--the number one cause of bird death.
Nationally, cats kill about 500 million birds per year, according to the American Bird Conservancy. By comparison, the US Fish and Wildlife Service states that wind turbines kill 440,000 birds per year--that's less than 1% of the number killed by cats. As wind farms sprout up across the US, expects turbines to kill over 1 million birds per year by 2030. Even so, that's a paltry sum compared to cats. So why all the hubbub about wind farms?
One reason may be that wind turbines are unnatural--people are fine with predators doing their thing, even if that thing is killing birds in the wild. By comparison, when human-made turbines kill birds, it makes us uncomfortable because it makes us responsible. But housecats and their feral cousins are certainly a human-related killer, too. They're not even native to North America.
Another potential reason is the NIMBY factor. NIMBY stands for "not in my back yard." It refers to situations where people reject a project, even if it's beneficial, because they don't want the negative consequences near their homes. NIMBY rears its head when people vote down a bus depot in their neighborhood, or when a group campaigns against a power plant near their homes.
Many such projects projects end up getting built in neighborhoods that don't complain--often in low-income neighborhoods, where people feel disengaged from the political process or don't have the time or money to spend fighting a project. Sometimes that's a good thing, if it's an important project and brings good things to the neighborhood. Other times it can lead to a concentration of polluting or otherwise nasty projects being built all in one place.
Courtesy Friedrich Tellberg
With wind turbines, many cite the birdie death toll, noise, and even appearance as reasons to cancel wind farm projects. But as technology improves, the turbines kill fewer birds and become quieter. New planning approaches site wind farms outside migratory paths so that birds are less likely to come into contact with them. They also place wind farms out to sea, or use designs that sit closer to the ground. There are really a ton of ideas blooming right now for wind power.
And as for the view, well, would you rather look at smog? Or cooling towers? I mean, power has to come from somewhere, and chances are it will involve building something.
But the cats, well…there isn't much you can do to improve them. (I know, I've tried teaching my cat to do the dishes, but she refuses to get her paws wet.) If you really want to help the birdies, perhaps the most effective method is to keep your kitties inside. I got mine a fake bird and she doesn't even know what she's missing.
Courtesy Mark RyanThis year marks the 150th anniversary of the announced discovery of the first fossils of Archaeopteryx, a remarkable chimera of both bird and reptile traits. The first evidence identified was a single feather discovered at a limestone quarry in Solnhofen, Germany. This was in 1860. The German paleontologist Hermann von Meyer described the fossil in 1861, naming it Archaeopteryx lithographica. That same year, the first skeletal remains came to light, and although headless, the London specimen, as it became known, showed clearly both avian and reptilian characteristics.
The unique and iconic fossil appeared just two years after publication of Charles Darwin’s On the Origin of Species and helped bolster the naturalist’s theory of evolution through natural selection because its appeared to be a transitional fossil between reptile (dinosaur) and bird. Could Darwin have asked for any better evidence?
Since then nine other specimens have been found, including the Berlin specimen around 1877, which is considered one of most complete. For many years some Archaeopteryx specimens languished in collection drawers because they had been initially misidentified as another creature entirely. In 1970, Yale paleontologist John Ostrom was investigating a so-called pteradactyl fossil at a museum in the Netherlands, when he realized it had been misidentified and was actually an Archaeopteryx. The fossil had been found at Solhofen in 1855, five years prior to the feather! The museum curator was so shaken by Ostrom’s announcement, he clumsily wrapped the specimen in a paper bag and presented it to Ostrom so he could take it back to Yale for further study. Ostrom, by the way, re-ignited the “birds are dinosaurs” debate in the 1960s after his discovery of Deinonychus and his comparison of its structural features with those of birds.
The Thermopolis specimen, the latest Archaeopteryx fossil, became known around 2005 and was donated anonymously to the Wyoming Dinosaur Center in Thermopolis, Wyoming. I happened to visit the museum in June of 2007 during the first week the fossil went on public display, and was able to see the spectacular specimen firsthand. The small fossil (about 1.5 feet square) was displayed behind a small, glass opening in the wall. There was no crowd to speak of so I was able to take in and photograph the fossil for a long stretch of time by myself. Looking at it, your eye is immediately drawn to the distinct feather impressions evident on both its wings and tail. The head, arms, and legs are spread out across the slab, and even though it died 150 million years ago, it looks as flat and fresh as road kill on a modern highway.
About the size of a large crow, Archaeopteryx was an odd amalgam of both bird and reptile. It had slightly asymmetrical flight feathers, wings, and a furcula (wishbone) - all traits found in birds. But its pelvis, skull and sharp teeth were reptilian (although some skull features are bird-like), and it ha a long tail like a reptile. Its bones weren’t hollow, like the bones of modern birds are, nor is its sternum (breastbone) very pronounced; it’s flatter and without a large keel where, in birds, muscles flight are attached. And it also possesses gastralia (“belly ribs”), a feature found in reptiles and dinosaurs. The inner toe (the hallux) in the Thermopolis specimen doesn’t appear to be reversed so it couldn't grasp or perch and was probably more earth-bound than arboreal. Interestingly, its second toe was extensible – meaning it could be pulled back and elevated for tearing into flesh, just like the middle toes of such dinosaurs as Troodon and Velociraptor. Truth be told, if its feathers hadn’t been preserved, Archaeopteryx would have been classified a carnivorous bipedal dinosaur. In fact, one of the existing Archaeopteryx fossil was first identified as a Compsognathus until preparation revealed its feathers.
Courtesy Ron Blakey, NAU GeologySo what kind of environment did Archaeopteryx live in, and why are its fossils so well preserved? Well, during the Late Jurassic, southern Germany and much of the rest of Europe were pretty much a group of large islands poking out of the Tethys Sea off the coast of North America. What is today the Solnhofen quarry was then part of an island lagoon protected by a barrier reef. Geological evidence in the strata suggests the lagoon dried up several times followed by periods of re-flooding with seawater. Mixed into a brackish soup of coral debris and mud, and in a warm climate conducive to rapid evaporation, the lagoon’s bottom water levels became anoxic, that is depleted of oxygen. Low oxygen meant less bacterial activity and subsequently slow decomposition of any organism that happened to die or get swept into the stagnant lagoon. Burial in the carbonate muck was swift, leaving fresh carcasses no time to be pulled apart by currents or scavengers.
Solnhofen limestone has been used for centuries as a building stone. Because the rock’s matrix is so fine and splits so evenly (sediment deposition likely occurred in very calm waters), the material was later quarried to produce stones for lithography, a printing technique first developed in 1796, and the source of Archaeoperyx’s species designation. Many early scientific illustrations, including some of the first images ofArchaeopteryx were preserved as lithographs created using Solnhofen limestone.
Courtesy Federal Republic of GermanySolnhofen’s fossil record shows that the lagoon’s biological population was diverse. Fish, turtles, lizards and insects, crocodiles, crustaceans, ammonites, squid and starfish, mollusks, pterosaurs, and even the soft remains of jellyfish are preserved in the fine-grained limestone. But the premiere creature is of course the Archaeopteryx, which remains the earliest bird (or most bird-like dinosaur, if you will) known to date. As research on existing specimens continues and new fossils appear it's exciting to imagine what advances will take place in the dinosaur-bird connection debate. Whatever happens, Archaeopteryx lithographica will remain one of the most significant and iconic fossils ever discovered. It's no wonder that later this year on August 11th, the Federal Republic of Germany will issue a 10 Euro silver coin to commemorate the 150th anniversary of the discovery of its most famous fossil.
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The mystery of why thousands of dead blackbirds were found in a small town in Arkansas on New Year's Eve has been solved. Loud sounds, possibly fireworks, scared the birds from their roosts, sending them into a panic that led them flying into house and in some cases, directly into the ground. Here's the initial video report of the event:
Courtesy Wikimedia CommonsA rare copy of naturalist and artist John James Audubon’s epic book, Birds of America, just sold at Sotheby’s auction for more than $10 million. That’s an enormous sum considering the book is essentially a work of natural history illustration. Also known as the Double Elephant Folio because of its large size, the massive tome opens to 4 feet across and contains hundreds of plates of exquisitely drawn, life-sized paintings of birds in their natural settings. It’s considered one of the greatest collections of natural history illustrations in the world, and I have to admit, after researching the story behind this stunning collection of work, and its creator, I understand why it's so valuable.
Courtesy Wikimedia CommonsIn the early 19th century, the Haitian-born Audubon (1785 - 1851) traveled across the eastern and central United States -often alone, sometimes with an assistant- to gather images of over 500 known species of bird. He would often draw them from life, but sometimes killed his avian subjects and posed them with wires in order to capture them on paper. The latter technique guaranteed the birds wouldn’t fly off. He used all sorts of media considered unconventional at the time to create his masterpiece images. Backgrounds were created sometimes by the artist himself but more often by several assistants.
Courtesy Wikimedia CommonsAudubon developed his deep interest in birds and natural history as a child growing up in France. At age 18 he arrived in the United States (as an illegal immigrant, mind you) where he honed his passion in ornithology in the woods surrounding the family property near Philadelphia.
Courtesy Wikimedia CommonsDuring his early days in America he worked at improving his drawing techniques, and became skilled at specimen preparation and taxidermy, even working for a time in that capacity at a museum in Cincinnati. On a return trip to France he met naturalist Charles-Marie D’Orbigny who schooled him in scientific methods of research and offered tips to improve his taxidermy skills.
Courtesy Wikimedia CommonsThe book Birds of America was a well-planned venture long before it finally came to fruition. Audubon had the title in mind when he set about in 1820 to paint every known bird in America. His goal was to eventually produce a body of work that would far surpass any other in existence. And he did exactly that. For nearly three years he roamed down the Mississippi River and across the American frontier searching out specimens to paint, sometimes purchasing them from local hunters.
Courtesy WikipediaAt the time Alexander Wilson was considered the leading ornithologist and painter of birds. He had cataloged most known birds in the country but his renderings were somewhat stiff and lifeless. Audubon worked persistently to make the birds in his drawings come to life, placing them in their natural ecosystems, often in active and dramatic poses. A single illustration would sometimes portray several species of bird.
Natural history illustration was and remains to this day crucial in disseminating scientific knowledge about the natural world. Detailed illustrations, graphics, and photographs help convey what's being explained in the text. Sometimes all the facets come together perfectly. Such is the case with Birds of America; its high regard is based on both its level of visual artistry and scientific information.
Since American printers couldn’t accommodate the oversize plates he insisted upon using, Audubon traveled to Great Britain where his paintings (and he himself) became an overnight sensation. The Brits were eager to learn anything about the new American frontier, its people and environs. The book’s original edition was printed by engraver Robert Havell (and son) starting in 1826. The process of engraving and printing all 435 plates took a dozen years and cost Audubon $111,640, a huge sum for the time. He financed the initial printing mainly through advance subscriptions, exhibitions, and lectures (a teen-aged Charles Darwin attended one of these).
Courtesy Wikimedia CommonsInitially, four title pages were sent to subscribers (including King George IV, an admirer of Audubon). Prints were then issued in groups of five with the idea the buyers – if they chose to do so - would bind them together at their own cost. Each separate illustration was printed in black and white using etching and aquatint techniques on large copper plates 39 x 28 in dimension. They were then each hand-painted by an army of colorists, a technique common in the 19th Century. An accompanying volume of text titled Ornithological Biographies was later added for each of the four plate volumes. The biographies match the illustrations in their scope. Audubon (aided by ornithologist William MacGillivray) gives a detailed description of each bird’s features (including drawings of internal organs), their behaviors, and the environments in which they lived.
Courtesy Wikimedia CommonsAudubon originally published about 750 copies of Birds of America of which only 219 copies are extant today. Of those, only 119 complete copies exist, most of which are in museum and library collections. Eleven copies are in private hands and this latest intact volume is one of two to be auctioned in the last decade. Over the years, many of the original editions were broken up and sold as individual illustrations. But with so few intact editions available now their value has skyrocketed against the amount single prints would attract.
After his death, Audubon’s wife sold most of the original paintings reproduced in Birds of America to the New York Historical Society for $4000! Luckily for us, the originals are occasionally put on display there, and that would be something to see. Audubon’s final project titled Vivaraporous Quadrupeds of North America was completed posthumously by his sons.
You'd be hard pressed to name a work of as monumental as Birds of America in terms of art and science, as it's considered by many to be one of the most important natural history books in existence. And Audubon was served well by it both financially and the worldwide acclaim it brought him. He was elected to the Royal Society of Edinburgh and the Linnaean Society, and was only the second American to be named a fellow by London's Royal Society (Ben Franklin was the first). Charles Darwin made three mentions of Audubon’s work in his own book On the Origin of Species. The ornithological organization the National Audubon Society is named in his honor. Not a bad legacy for a backwoods kid who just loved birds.
"Australian brush turkeys (Alectura lathami) are what biologists call "super precocial," says Ken Dial of the University of Montana Flight Lab. The birds fly the day they hatch, and hatchlings can climb vertical ledges better than adults, according to Dial's latest research."
The fossil remains of a giant five-foot penguin has been unearthed in Paracas National Reserve, a desert region along the coast of Peru. The new species, named Inkayacu paracasensisI (water king), grew to a size nearly twice as large as the modern day Emperor penguin. The nearly complete fossil even skeleton included flippers and feathers. Some color of a bird's feathers can be deduced by the size of the melanosomes in its structure and by their shape and arrangement. When Inkayacu's melanosomes were compared with those of modern day birds, the nanostructures indicated that the giant penguin's feathers were reddish brown in color.
"Before this fossil, we had no evidence about the feathers, colors and flipper shapes of ancient penguins," said paleontologist Julia Clarke, of the University of Texas, and lead author of the report that appears in Science. The new evidence brings up new questions. For example, Clarke and her team aren't sure when or why the feather colors of most modern penguins shifted to black and white. I. paracenensis lived during the Eocene epoch 36 million years ago, and its fossil has been nicknamed Pedro.