Beaver teeth found are 7m years old

A fossil found on government land is the earliest record of living beavers in North America.

The pair of teeth was found on Bureau of Land Management property in north-east Oregon.

The Albany Democrat-Herald said the teeth come from the Rattlesnake Formation and are 7-7.3 million years old.

The BLM says the earliest beavers were found in Germany 10 to 12 million years ago and the animals spread across Asia, eventually crossing the Bering Land Bridge to North America.

The previous earliest known records of living beavers in North America, from about five million years ago, were from Nebraska, California, and northern Oregon.

The fossils will be displayed at the Thomas Condon Palaeontology Centre at John Day Fossil Beds National Monument.

http://news.uk.msn.com/world/beaver-teeth-found-are-7m-years-old

Wild Beavers Terrorize Philadelphia

Wikimedia

Three people were bitten by a rabid beaver last week in Philadelphia before

the animal was killed -- and game wardens remain stumped about the "truly

bizarre" attacks.

Published June 06, 2011 | NewsCore

PHILADELPHIA – Pennsylvania game wardens remained stumped Sunday about a spate of "truly bizarre" rabid beaver attacks in and around Philadelphia.

Three people were bitten by a beaver last week in Pennypack Park in the city's northeastern section before the animal was killed and officials determined it had rabies, according to MyFoxPhilly.

A married couple was fishing on Wednesday when the large beaver bit the woman's leg, then turned on her husband and bit him in both arms and on his chest, the Pennsylvania Game Commission said.

On Thursday, a child was bitten in the same park. A short time later, a park ranger located the beaver nearby. That animal was killed and tested positive for rabies at a Health Department lab. Game wardens are looking through the park for other beavers that could be infected.

Park officials were baffled by the location of the attacks and the fact that the mammal was a beaver -- not a raccoon or skunk.

"It's not that beavers are not susceptible, as all mammals are susceptible, to rabies," said Game Commission spokesman Jerry Feaser. "But a beaver in Philadelphia, that was just truly bizarre."

Another rabid beaver attacked an angler in late April on White Clay Creek in the Chester County suburbs of Philadelphia. Feaser said the attacks are the only such cases he recalls during 12 years with the commission.

"Our furbearer biologist, when he heard about this, he was just literally blown away," Feaser said.

The state Agriculture Department, which investigates rabies cases, fielded no reports of rabid beavers in 2009 or 2010.

Pennsylvania normally has between 350 and 500 confirmed rabies cases annually. Last year slightly more than half the cases were raccoons, followed in frequency by skunks, cats, bats and foxes. The state's most recent rabies fatality for humans occurred in 1984, when a 12-year-old Lycoming County boy died.

As a precaution, Game Commission officials continue to encourage residents to avoid the Pennypack Creek waterfront area between Bustleton Avenue and Roosevelt Boulevard in northeast Philadelphia.

Read more on Philadelphia's beaver battle at MyFoxPhilly.com.

http://www.foxnews.com/scitech/2011/06/06/wild-beavers-terrorize-philadelphia/

Secret lives of baby American beavers filmed

The secrets lives of beavers have been revealed by a new study.

Using discreet video cameras, scientists have been able to study the long-term natural behaviour of beavers "at home" in their lodges.

The tiny, waterproof cameras, inserted into beaver dens, show that beavers lead very different private lives when at home than when outside.

At home, the animals are surprisingly co-operative and scientists have even recorded baby beavers growing up.

Much of what we know about beavers and their use of dens is limited to questions like 'what times of day do they go in and out of the den'", says Cy Mott, a biologist at Kentucky Wesleyan College, in Owensboro, US.


"Simply because, until recently, we haven't had the technology to follow their behaviour within the den without potentially disturbing natural behaviour."

So Professor Mott and colleagues, Craig Bloomquist and Clayton Nielsen of Southern Illinois University in Carbondale, US, decided to study American beavers (Castor canadensis) denning on the Mississippi flood plain in south-western Illinois.

Beavers in this region declined drastically in the 19th and 20th Centuries, but have since recovered due to a ban on hunting them for their pelts.

The researchers used special "probe" cameras that do not disturb the beavers to record the animals' behaviour in 23 colonies over the course of more than a year.

Beavers make sophisticated homes, either in dens burrowed into river banks, or more complex lodges.


Lodges are essentially dens built from wooden branches that are surrounded by water, the level of which beavers help maintain by also building wooden dams.

Video taken of beavers within 17 lodges and six bank dens revealed some surprising behaviours.

Living in their elaborate shelters, beavers were thought to be cut off from the outside environment.

But the video study shows that they exhibit regular patterns of behaviour, leaving to feed at roughly the same time every day, for example.

"This suggests that they may not be as cut off from the external environment as we think they are," says Professor Mott.

Male and female beavers appear to take equal responsibility for raising their babies, known as kits, perhaps because the young are so "high maintenance".


In the privacy of their own home, beavers also spend 95% of their time feeding, sleeping, and grooming.

"It supports the assumption that the relative security of the den is a place where they can exhibit behaviours that would be potentially dangerous outside of dens," says Professor Mott.

Baby sleep
Another surprise relates to the private lives of baby beavers, and their sleeping patterns.

Baby beavers, and adults, follow a similar sleep schedule to humans, the researchers report in the journal Mammalian Biology.

Adults beavers tended to sleep at a similar time, though not all the adults fall asleep at once, perhaps to ensure the babies are looked after.

"Kits, on the other hand, exhibited multiple sleep wake cycles throughout the day and night, with each interval lasting only a few hours, much like a human infant waking up every few hours during the night," says Prof Mott.

Finally, "given that beavers are in incredibly close confines within dens, we fully expected to document aggressive behaviours," he explains.

Most social animals that live in close-knit groups tend to use aggression to establish a "pecking order" between individuals.

But "one of the most interesting things we didn't find was aggression within beaver colonies," Prof Mott told the BBC.

The researchers know of only two previous studies that attempt to explain what happens within a den, despite the fact that beavers spent considerable portions of their lives in these structures.


In one study, scientists cut away one side of a lodge to view the beavers directly via a glass panel, which likely disturbed the animals' natural behaviour.

The other study consisted of a researcher "listening in" while outside the lodge, in an attempt to describe what was happening inside.

"To our knowledge, our study is the first to use long-term video data to follow behaviour for months at a time, over successive years, and even during the period from birth of beaver kits until they disperse to find territories of their own," says Professor Mott.

By Matt Walker

Editor, Earth News

http://news.bbc.co.uk/earth/hi/earth_news/newsid_9283000/9283367.stm

Secret lives of baby American beavers filmed

The secrets lives of beavers have been revealed by a new study.

Using discreet video cameras, scientists have been able to study the long-term natural behaviour of beavers "at home" in their lodges.

The tiny, waterproof cameras, inserted into beaver dens, show that beavers lead very different private lives when at home than when outside.

At home, the animals are surprisingly co-operative and scientists have even recorded baby beavers growing up.

Much of what we know about beavers and their use of dens is limited to questions like 'what times of day do they go in and out of the den'", says Cy Mott, a biologist at Kentucky Wesleyan College, in Owensboro, US.


"Simply because, until recently, we haven't had the technology to follow their behaviour within the den without potentially disturbing natural behaviour."

So Professor Mott and colleagues, Craig Bloomquist and Clayton Nielsen of Southern Illinois University in Carbondale, US, decided to study American beavers (Castor canadensis) denning on the Mississippi flood plain in south-western Illinois.

Beavers in this region declined drastically in the 19th and 20th Centuries, but have since recovered due to a ban on hunting them for their pelts.

The researchers used special "probe" cameras that do not disturb the beavers to record the animals' behaviour in 23 colonies over the course of more than a year.

Beavers make sophisticated homes, either in dens burrowed into river banks, or more complex lodges.


Lodges are essentially dens built from wooden branches that are surrounded by water, the level of which beavers help maintain by also building wooden dams.

Video taken of beavers within 17 lodges and six bank dens revealed some surprising behaviours.

Living in their elaborate shelters, beavers were thought to be cut off from the outside environment.

But the video study shows that they exhibit regular patterns of behaviour, leaving to feed at roughly the same time every day, for example.

"This suggests that they may not be as cut off from the external environment as we think they are," says Professor Mott.

Male and female beavers appear to take equal responsibility for raising their babies, known as kits, perhaps because the young are so "high maintenance".


In the privacy of their own home, beavers also spend 95% of their time feeding, sleeping, and grooming.

"It supports the assumption that the relative security of the den is a place where they can exhibit behaviours that would be potentially dangerous outside of dens," says Professor Mott.

Baby sleep
Another surprise relates to the private lives of baby beavers, and their sleeping patterns.

Baby beavers, and adults, follow a similar sleep schedule to humans, the researchers report in the journal Mammalian Biology.

Adults beavers tended to sleep at a similar time, though not all the adults fall asleep at once, perhaps to ensure the babies are looked after.

"Kits, on the other hand, exhibited multiple sleep wake cycles throughout the day and night, with each interval lasting only a few hours, much like a human infant waking up every few hours during the night," says Prof Mott.

Finally, "given that beavers are in incredibly close confines within dens, we fully expected to document aggressive behaviours," he explains.

Most social animals that live in close-knit groups tend to use aggression to establish a "pecking order" between individuals.

But "one of the most interesting things we didn't find was aggression within beaver colonies," Prof Mott told the BBC.

The researchers know of only two previous studies that attempt to explain what happens within a den, despite the fact that beavers spent considerable portions of their lives in these structures.


In one study, scientists cut away one side of a lodge to view the beavers directly via a glass panel, which likely disturbed the animals' natural behaviour.

The other study consisted of a researcher "listening in" while outside the lodge, in an attempt to describe what was happening inside.

"To our knowledge, our study is the first to use long-term video data to follow behaviour for months at a time, over successive years, and even during the period from birth of beaver kits until they disperse to find territories of their own," says Professor Mott.

By Matt Walker

Editor, Earth News

http://news.bbc.co.uk/earth/hi/earth_news/newsid_9283000/9283367.stm