Mangy wolves suffer hefty calorie drain on cold, windy winter nights
Mar30

Mangy wolves suffer hefty calorie drain on cold, windy winter nights

An unwelcome dieting plan: severe mange infection could increase a wolf’s body heat loss by around 1240 to 2850 calories per night, which is roughly 60-80 percent of the average wolf’s daily caloric needs. During winter, wolves infected with mange can suffer a substantial amount of heat loss compared to those without the disease, according to a study by the U.S. Geological Survey and its partners, published as an Accepted Article (preprint release of the accepted manuscipt) yesterday in ESA’s journal Ecology. The lost calories equal about two to four extra pounds of elk meat per day, said lead author Paul Cross. “By definition, parasites drain energy from their hosts. In this study we estimated just one portion of the energetic costs of infection,” said Cross. “Even when parasites do not kill their hosts they are affecting the energy demands of their hosts, which could alter consumption rates, food web dynamics, predator-prey interactions and scavenger communities.” Sarcoptic mange, present in one of 10 known packs in Yellowstone as of 2015, is a skin disease caused by a mite that burrows into the skin, causing irritation and scratching that then leads to hair loss. In the early 1900s, the Montana state wildlife veterinarian introduced mange to the Northern Rockies  in an attempt to help eradicate local wolf and coyote populations. Using a remotely triggered thermal camera to capture vivid and colorful images, Cross and colleagues gathered body temperature data from mange-infected gray wolves in Yellowstone National Park and compared that to a sample group of healthy captive wolves with shaved patches of fur to simulate mange-induced hair loss. Using these data, they quantified the level of heat loss, or energetic costs, during the winter months. Read a summary of the research from the USGS or check out the research article: Cross, P., Almberg, E., Haase, C., Hudson, P., Maloney, S., Metz, M., Munn, A., Nugent, P., Putzeys, O., Stahler, D., Stewart, A. and Smith, D. (2016), Energetic costs of mange in wolves estimated from infrared thermography. Ecology. Accepted Author Manuscript. doi:10.1890/15-1346.1...

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The Great Backyard Bird Count

By Liza Lester, ESA communications officer A brown pelican, photographed during the 2010 Great Backyard Bird Count by Bob Howdeshell, of Tennessee. Used by permission. ______________________ THIS WEEKEND, as the US celebrated President Washington’s birthday, the National Audubon Society, Bird Studies Canada, and the Cornell Lab of Ornithology were celebrating birds, with the fifteenth annual Great Backyard Bird Count. As the name implies, this four-day event includes the backyard observations of bird-feeding enthusiasts and birding newbies, as well as the more far-flung reports of sturdy winter hikers and wilderness refuge visitors. The organizers distinguish between “stationary counts” made in backyards and “traveling counts” taken by birders strolling through parks, and provide printable bird checklists organized by zip code. You can watch the data come in on the Bird Count’s live-action map, until data entry closes on March 5th (the counts must have been made between Feb. 17th and Feb. 20th, however). As of today, participants have observed 597 species and submitted 79,176 checklists. Since even couch-bound, self-quarantined residents of urban habitats like our nation’s capital can join the fun, I took my cold medicine and Kleenex, bundled up in a down vest, and settled in on my porch to look for my feathered neighbors. During my hour on the porch (the program asks that you spend at least fifteen minutes, and note the exact time and location), the sun went down, and five specimens of the ubiquitous American Robin bounced about the lawn, flashing their distinctive ruddy chests. To avoid counting the same birds twice, the program instructs participants only to report the largest grouping of a species seen at one time, which did make deciding how many robin were bouncing around easier. I glimpsed a white-black-white fan of tail-feathers retreating into a neighbor’s shrubbery. After consulting with the Cornell Lab’s online bird guide, I guessed that it was a Dark-eyed Junco. A flock of birds too small to see perched in the high branches of a maple. This bird-counting game was harder than it sounded! For new recruits interested in getting deeper into birding, the robust website includes articles about bird-feeders, bird identification, and binoculars. The site is packed with photos, information about birds, and educational ideas. How does the program integrate counts from noobs like me with ecological models and data from experienced birders, who know their Fox Sparrows from their Field Sparrows? It combines the thousands of reports to build of snapshot of bird presenteeism across North America’s winter landscape. Linking bird sightings to locations and dates allows scientists to map bird population movements to coincident phenomena like weather, or disease. They can look for changes...

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Snowflakes still hold mystery

This post contributed by Nadine Lymn, ESA Director of Public Affairs Their silent, shimmery beauty has long stirred human aesthetic appreciation and for centuries individuals have sought to unravel the secrets of snowflakes.  Why are there so many varieties?  Why do all snowflakes have six “arms”?  And why does each flake appear unique, no matter how many fall from the sky? We know the answers to these questions as described on the National Oceanic and Atmospheric Administration’s website: temperature and humidity determine their shape, their six “arms” are the result of the internal order of an ice crystal’s water molecules, and, because each crystal encounters slightly different atmospheric conditions, each snowflake appears unique. But enough mystery about the particulars remains that some scientists continue to try to unravel it.  One such scientist is Caltech physicist Kenneth Libbrecht, who is looking into the physics of exactly how water vapor molecules are incorporated into a growing ice crystal.  He has also created a webpage, SnowCrystals.com which is a true treasure-trove of information for anyone interested in snowflakes.  It includes not only magnificent photographs taken by Libbrecht, such as the one below, but also showcases the science of snowflakes and the historical figures who sought to understand these ephemeral beauties. For example, as long ago as 1611, German mathematician Johannes Kepler, put together a “treatise” for the king which he entitled, A New Year’s Gift or On the Six-Cornered Snowflake. Libbrecht notes that this was the first scientific reference to snow crystals and that Kepler was especially intrigued by the six arms of snowflakes, speculating that it must have something to do with the morphology of the crystals. The website includes other individuals, such as “Snowflake Man” Wilson Bentley, a self-educated Vermont farmer, who became so enraptured with snowflakes he saw under his microscope that he persuaded his parents to purchase a special bellows camera to try to capture them before they melted.  After years of trial and error, Bentley became the first person to take a photomicrograph of an ice crystal and went on to capture 5,000 images of snowflakes.  According to Duncan Blanchard, who wrote a biography about him, Bentley’s first article appeared in Popular Scientific Monthly in 1898 and included this vivid description of an ice crystal: “A careful study of this internal structure not only reveals new and far greater elegance of form than the simple outlines exhibit, but by means of these wonderfully delicate and exquisite figures much may be learned of the history of each crystal, and the changes through which it has passed in its journey through cloudland.  Was ever life history written in more...

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Waves mightier than sun, otter or urchin: storm disturbance shapes California kelp forests

This post contributed by Liza Lester, ESA communications officer. As winter storms pick up along the California coast, a harvest of giant kelp comes ashore with the tides, torn from seafloor anchorages by the rough action of waves. Waves are the most powerful force shaping the kelp forest, superseding the influence of temperature, nutrients, and hungry animals, say University of California, Santa Barbara (UCSB) researchers in the November issue of Ecology. From Alaska to Baja California, kelp undulates in the currents of rocky coastal shallows, feeding and sheltering a host of sea creatures and birds. Americans harvest kelp for food and fish feed, and the kelp forest harbors commercially valuable fish and shellfish. In central and southern California, the giant kelp predominates. Macrocysits pyrifera anchors at depths of 6 to 150 feet, and is the largest alga in the world, reaching underwater heights of nearly 150 feet in a single season. Conversion of sunlight into kelp fuels an ecosystem. “Primary production is the amount of plant material produced per unit area of the Earth’s surface per unit time. It’s really the basis of all life on Earth for the most part,” said Dan Reed, research biologist at the Marine Science Institute at UCSB, and principle investigator of the Santa Barbara Coastal Long Term Ecological Research project. In the kelp forest, the primary producer is the kelp itself. Reed and his colleagues wanted to know how periodic disturbances from large waves stacked up against other influences on kelp forest growth. Lack of nutrients, particularly nitrogen, slows the kelp’s exuberant expansion, as do the teeth of small, but numerous, sea animals. Kelp is the favorite food of the sea urchin, as commercial harvesters of the fist-sized, spiky animal well know. Urchins do not climb the kelp stalks. They forage across the seafloor, devouring fallen kelp blades (analogous to leaves) and chunks. But their powerful, self-sharpening teeth can also chew through the holdfasts of the kelp, releasing the giants to the mercies of the ocean currents, as graphically exhibited by time-lapse footage in the BBC’s documentary Planet Earth. In concentrated herds, unchecked urchins have been known to raze entire forests. The check on the urchin is the sea otter, a top predator of the kelp forest. The demands of the otters’ high metabolisms drive them to eat up to a fourth of their body weight in invertebrates daily, and they like sea urchins. The otters are a classic example of a keystone species, an animal whose eating habits tip a crucial balance in a cascade of consumer-and-consumed reactions. The arrival of otters in new territory has changed relatively barren, stony seafloor into...

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Snow fleas: helpful winter critters

As the Northeast of the United States was hammered by thundersnow this week, students, parents and perhaps those working from home had the opportunity to indulge in outdoor winter activities. For many, being in the snow again is losing its luster. As an Associated Press article noted, “The Northeast has already been pummeled by winter not even halfway into the season. The airport serving Hartford, Conn., got a foot of snow, bringing the total for the month so far to 54.9 inches and breaking the all-time monthly record of 45.3 inches, set in December 1945.” However, those who are venturing outside might discover that snow forts and shovels are not the only things littering the fresh snow. At close examination, perhaps in melting snow around the base of a tree, tiny black flecks might be found sprinkled in the snow. They probably look like bits of dirt at first glance, but they are actually tiny soil animals known as snow fleas. Officially, they are called springtails and are not actually fleas (or even technically insects). On any given summer day, hundreds of thousands of springtails can populate one cubic meter of top soil; at 1-2 mm, they largely go unnoticed by people. In the winter, however, two species of dark blue springtails— Hypogastrura harveyi and Hypogastrura nivicol—can be easily spotted against the white backdrop of snow. These hexapods may have acquired the nickname of snow fleas due to their ability to jump great distances, a feat fleas boast as well. Whereas fleas use enlarged hind legs, springtails have a tail-like appendage called a furcula that unfolds to launch the hexapods great distances. But unlike fleas, springtails are not parasites; they feed on decaying organic matter in the soil (such as leaf litter) and, therefore, play an important part in natural decomposition. Snow fleas in particular are able to withstand the bitter temperatures of winter thanks to a “glycine-rich antifreeze protein,” as reported in a study published in Biophysical Journal. The protein in the snow fleas binds to ice crystals as they start to form, preventing the crystals from growing larger. In addition, by isolating this protein, researchers have been able to study the medical potential of its structure. Specifically, Brad Pentelute from the University of Chicago and colleagues suggested the possible applications of this protein in safely preserving organs for human transplantation. LIN, F., GRAHAM, L., CAMPBELL, R., & DAVIES, P. (2007). Structural Modeling of Snow Flea Antifreeze Protein Biophysical Journal, 92 (5), 1717-1723 DOI: 10.1529/biophysj.106.093435 Photo Credit (distance snow fleas): Jean-Sébastien Bouchard Photo Credit (snow flea close-up): Daniel Thompkins As the Northeast of the United States was hammered...

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If you give a mouse an acorn…

The following is a story, but it describes a real scientific process: the relationship between acorns, mice, ticks and a bacterium. On a chilly November night, in a deciduous forest in the eastern U.S., a mouse prepares for the season ahead. More specifically, a female white-footed mouse—competing with other mice and animals for acorns—is reaping the fruits from a mast year: The oak trees in the region produced a generous blanket of acorns across the forest floor this autumn.

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