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American Eels Return to Mountain Streams after Dam Removal

By Guest PostAugust 1, 2012Environment, Naturealan weaver, american eel, anguilla rostrata, atlantic coast, dam, dam removal, embrey dam, endangered species, fredericksburg, freshwater eel, freshwater stream, greenland, hydroelectric power, jeb wofford, life cycle, migration barrier, mountain streams, nathaniel hitt, rappahannock river, sargasso sea, sheila eyler, shenandoah national park, south america, usgs, virginia

Shenandoah National Park, Va. – American eels are declining across their range but are showing indications of a population revival following the removal of a large dam in Virginia.

The removal of Embrey Dam on the Rappahannock River increased American eel numbers in headwater streams nearly 100 miles away, according to research just published by U.S. Geological Survey, U.S. Fish and Wildlife Service, and National Park Service researchers.

American eels undergo long-distance migrations from their ocean spawning grounds in the Sargasso Sea to freshwater streams along the Atlantic coast from northern South America to Greenland. Dams may slow or even stop upstream eel migrations. However, prior to this research, little was known about American eel responses to dam removal. (more…)

Critically Endangered Whales Sing Like Birds; New Recordings Hint At Rebound

By Guest PostAugust 1, 2012Naturebowhead whale song, sing like birds, singing whales, whale song, whales

When a University of Washington researcher listened to the audio picked up by a recording device that spent a year in the icy waters off the east coast of Greenland, she was stunned at what she heard: whales singing a remarkable variety of songs nearly constantly for five wintertime months. (more…)

Public Sightings Suggest Increase in Basking Sharks in British Waters

By Guest PostJuly 30, 2012Naturebasking sharks, brendan godley, british waters, cornwall wildlife trust, fishery, ireland, jean luc solandt, marine conservation, northeast atlantic, norway, public sightings, ruth williams, scotland, shark, uk water, university of exeter

The number of basking sharks recorded in Britain’s seas could be increasing, decades after being protected from commercial hunting in the late 20^th century.

The most comprehensive analysis ever undertaken of basking shark sightings in UK waters, by the University of Exeter, the Marine Conservation Society (MCS), Cornwall Wildlife Trust (CWT) and Wave Action, is published in the journal Marine Ecology Progress Series.

The northeast Atlantic hosted an extensive commercial fishery for basking sharks, mainly in Norway, Ireland and Scotland, where more than 81,000 were killed between 1952 and 2004, hunted largely for their liver oil. Large-scale hunting ended in the UK in the middle of the twentieth century, though it continued at low levels in Norway until 2000. (more…)

From a Few Bones, the Most Primitive Snake Emerges

By Guest PostJuly 29, 2012Naturebhart anjan bhullar, bone, coniophis precedens, cretaceous period, dinosaurs, eastern wyoming, floodplain, gila monster, jacques a gauthier, lizard, lucy, marine ancestor, montana, nicholas longrich, pipe snake, primitive snake, protosnake, salamander, serpentine body, snake origin, t rex, triceratops, vertebrae characteristic, yale

Researchers at Yale have identified an ancient slithering creature from the time of T. rex as the most primitive known snake, a finding with implications for the debate over snake origins.

“It’s the missing-link snake,” said Nicholas Longrich, a postdoctoral fellow in Yale’s Department of Geology & Geophysics and the lead author of a paper about the lizard-like snake published July 25 online in the journal Nature. “It’s the ‘Lucy’ of snakes.”

The paper argues that snakes descend from terrestrial rather than marine ancestors, as recently proposed by others, and that snakes emerged once lizards developed long, limbless bodies for burrowing. (more…)

Growing Threats to Biodiversity ‘Arks’

By Guest PostJuly 25, 2012Naturearks for biodiversity, deforestation, old trees, original biodiversity

Many of the protected areas in tropical nations are struggling to sustain their biodiversity, according to a study by more than 200 scientists from around the world. The study, which will appear Thursday in the journal Nature, found that deforestation is advancing rapidly in these nations and most reserves are losing some or all of their surrounding forest. (more…)

Thieving Rodents: Did They Save Tropical Trees?

By Guest PostJuly 18, 2012Nature

Rodents may have taken over seed-dispersal role of now-extinct mammals

Big seeds produced by tropical trees such as black palms were probably once ingested and then left whole by huge mammals called gomphotheres.

Gomphotheres weighed more than a ton and dispersed the seeds over large distances.

But these Neotropical creatures disappeared more than 10,000 years ago. So why aren’t large-seeded plants also extinct? (more…)

Ribbeting Research

By Guest PostJuly 13, 2012Nature, Scienceacoustic difference, amphibians, amplexus, cocktail party problem, eardrum movement, eustachian tubes, female cope, frog ears, frogs, gray treefrog, hearing aids, jackhammer, mammalian ears, mammals, mark bee, mr right, study, university of minnesota, velocity

Studies of frogs may lead to better hearing aids

When Mark Bee talks to his 106-year-old grandmother alone, her two enormous hearing aids enable her to understand him well.

“But at a table at Thanksgiving, with everybody talking, the devices don’t do well,” says Bee, an associate professor of ecology, evolution and behavior at the University of Minnesota.

Her difficulty in a noisy situation is called the cocktail party problem, after the background babble that stymies many hearing-impaired people trying to pick out individual voices at a party. But in ponds all over the world, frogs handle a similar problem, and Bee hopes to learn enough about how they do it to put the principles to work helping people like his grandmother. (more…)

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