Posts for 'Societies for Mammals' Category

Paleontologists in the U.S. and China have discovered a new species of mammal that lived 123 million years ago in what is now the Liaoning Province in China.

The newly discovered chipmunk-sized animal, named Maotherium asiaticus, was found in the famous fossil-rich beds of the Yixian Formation in China.

The fossil mammal, reported in this week's issue of the journal Science, offers an important clue to how the mammalian middle ear evolved. It represents an intermediate stage in the evolutionary process of how modern mammals acquired a middle ear structure.

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The National Audubon Society Guide To Marine Mammals Of The World uses the word “aggregation” to describe dolphins that come together only for purposes of feeding. These dolphins are linked in this case by a practical purpose and will break back down into more stable and normal social groupings once they eat enough fish.

In Jean-Jacques Rosseau’s The Social Contract, Rosseau uses the word “association” to describe people in political union or unified in some way transcendent of immediate needs.I was reading both books around the same time. Seeing both words used in these ways got me to thinking about why we spend time with the people we spend time with.

For example, on a city bus you have an aggregation. The people are on the bus only until they reach the right stop.At work, you might have of mix. At core it’s an aggregation because you are the there to get a job done and earn a living. But with time, as relationships form and the common purpose, possibly, takes on more meaning, an association may exist.

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Air Canada must allow passengers to take along their pets on its domestic and international flights, the Canadian Air Transportation Agency ruled Friday.

The airline changed its policy last summer so that passengers could no longer transport cats, dogs and other small animals on planes as checked baggage on the grounds that more space was needed to accommodate luggage. Instead, passengers were told their pets would have to travel separately aboard cargo planes.

In its decision, the agency called Air Canada's policy "unreasonable" because it favours the air carrier while exposing pets to harm.

The airline has until May 5 to comply with the ruling and allow animals and their crates, with a combined weight of less than 31 kilograms, to be transported on all flights.

The investigation followed a complaint from a passenger, Peter T. Griffiths, who said the policy would cause considerable inconvenience to people travelling with their pets and increase their costs.

"The fee I would be charged would more than double from the current $105 to $220 each way for my six-kilogram dog," he wrote. "It is very clear the sole purpose of this decision is the financial gain in the very lucrative air cargo market."

What North American mammal eats cactus, lizards and acorns – and has sharp tusks?  What mammal eats its own weight in insects and earthworms every day? These creatures and more are in the pages of this fabulous guide to 110 of the most common mammals from the Arctic to the Mexican border, from the Pacific coast to the Atlantic. Tracks, sign, habits and habitat are all in here and will serve your family for years on trips to the backyard and beyond.

This guide is used at Wilderness Awareness School Summer Day Camps and is the recommended youth field guide by our school on this subject.

Of course, this is a valuable guide for folks of all ages, but the simpler guides are most useful and inspiring for young people.

A new cage to transport sick marine mammals was delivered Thursday to the Marine Mammal Center by a man who knows a little something about bars: San Quentin State Prison Warden Robert Ayers Jr.
Inmates at San Quentin's metal shop made the cage, which has wheels and will make it easier to move the sometimes massive marine creatures.

Ayers got a tour of the Marin Headlands center, which is undergoing a $25 million expansion project.

Anti-war activists in Marin are gearing up for an attempt to get local city councils to pass resolutions calling for a withdrawal of U.S. troops from Iraq.

"Once in a while, people get so frustrated with their state or federal governments that they say, 'What's wrong with those people? I want to go to my city council and see if they'll take a position and agree with me, because their voice is bigger than mine in Sacramento or Washington, D.C.,'" said San Rafael Councilman Greg Brockbank.

But no one in Marin so far has suggested going as far as the towns of Marlboro and Brattleboro in Vermont, where voters passed articles calling for the indictment of President George W. Bush and Vice President Dick Cheney for violating the Constitution. Voters there directed police to arrest Bush and Cheney if they ever visited.

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The brain undergoes a complicated pattern of development in the embryo. This development is similar in birds, mammals and humans.

An embryo has three basic layers that begin as simple layers of cells programmed by genes to become different parts of the body. The outer layer, the ectoderm, becomes skin, brain and nervous system. The middle layer, the mesoderm, becomes muscle and bone. The inner layer, the endoderm, becomes the gastrointestinal tract and abdominal organs. The retina, the nerve-cell layer of the eye, develops as a part of the brain and later is connected to the tissues which make up the eye. Thus, the eye is a part of the brain that looks out on the world.

There is, however, an important difference between human brains and the brains of all other members of the animal kingdom. No, I am not referring to size. Porpoises and whales have us beat on that point. The difference is that our brains are more immature at birth than any of the others.

The neurons in the human brain are dividing actively at birth and continue to do so until about age 2. By that time, we have all the neurons we will ever have. In fact, we will have fewer neurons as adults because of a pruning process, called apoptosis, which reorganizes our brains under hormonal control at puberty, so that our thoughts will have structure and reasoning ability. Puberty is the age where we begin to ask important questions and begin to doubt that the world is the perfect place we thought it was as a child.

To emphasize this point, the brain of a chimpanzee is as developed at birth as humans are at 2 years of age, and they are ready to start fending for themselves within a few weeks. Obviously, parental care is not necessary after 1 to 2 years. The question: why?

The answer is not complete and awaits ongoing research, but is appears that the cause is the development of upright posture, which resulted in a closed pelvis, thus limiting head size at birth at the same time that the brain was growing larger. As anyone who has dealt with birth problems, animal or human, knows, a large head and small pelvis always is a problem.

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A remote-controlled plane will be tested for use in counting dugongs and whales in Moreton Bay next month.

Australian researchers are investigating whether Unmanned Aerial Vehicles (UAV) are a better way to count marine mammals than traditional methods such as using boats or manned aircraft.

Migrating humpbacks and dugongs will be captured via a specialised video camera system attached to the three-metre long plane.

The plane costs about $100,000, has a wingspan of five metres, a maximum range of 1500 kilometres and a top speed of 200 kilometres an hour.

Marine mammal survey and tracking experts from UQ, James Cook University (JCU) and The University of Newcastle are working with Jimboomba UAV business, Aerocam Australia on the test flights.

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A remote-controlled plane will be tested for use in counting dugongs and whales in Moreton Bay next month.

Australian researchers are investigating whether Unmanned Aerial Vehicles (UAV) are a better way to count marine mammals than traditional methods such as using boats or manned aircraft.

Migrating humpbacks and dugongs will be captured via a specialised video camera system attached to the three-metre long plane.

The plane costs about $100,000, has a wingspan of five metres, a maximum range of 1500 kilometres and a top speed of 200 kilometres an hour.

Marine mammal survey and tracking experts from UQ, James Cook University (JCU) and The University of Newcastle are working with Jimboomba UAV business, Aerocam Australia on the test flights.

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Researchers at the University of California, Santa Cruz have found out what prevents dolphins, whales, sea otters and certain other marine mammals from brain damage despite there being very low oxygen supply underwater.

Humans, even well-trained Olympic swimmers, cannot survive longer than a few minutes underwater because their brains need a constant supply of oxygen that they do not get beneath water.

However, Weddell seals that dive and hunt under the Antarctic sea ice remain unfazed by low levels of oxygen.

Lead researcher Terrie Williams, professor of ecology and evolutionary biology, believes that elevated levels of oxygen-carrying proteins in the marine creatures brain protect it from brain damage.

The researchers measured and compared the amounts of such complex oxygen-carrying proteins, known as globins, in the cerebral cortex of 16 different mammalian species.

They observed that some species had evolved the capacity to protect their brains from conditions of low oxygen, also called hypoxia.

“What was remarkable was the level of variability we found. Some animals had three to 10 times more neuroprotecting type globins than others. These wild species may hold many clues about how to turn on protective mechanisms in the mammalian brain,” said Williams.

She said that her teams discovery could have important implications for understanding stroke and aging in humans.

Terrie admitted that her team was yet unsure whether animals of a particular species are born with high amounts of brain globins, or whether their behaviour and environment stimulate the production of globins. She, however, said that in either case, the amounts appeared to be malleable.

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Scientists are developing a new branch of network theory to understand zebra communities
Dan Rubenstein of Princeton University is an ecologist who has studied zebras and other horse-like animals for 20 years. To understand their social structure, he makes graphs of their interactions, with a separate graph for each season. Each zebra corresponds to a node on a graph (drawn as a dot), and two zebras are connected by a line if they've come within a few feet of each other during a given season. Rubenstein first graphed data showing the interactions among Grevy's zebras and among onagers, a closely related horse-like species. Both are fission-fusion societies without stable harems, so he expected the graphs to look similar. But in fact, the zebra graph had masses of tightly connected clumps, whereas the onager graph sprawled across the page, with looser and more random connections. The difference showed that the Grevy's zebras tended to hang out in cliques, whereas the onagers spent time with different buddies on different days.
Rubenstein was thrilled to see that network theory revealed patterns he wouldn't have seen otherwise, and he started thinking of all the other questions network theory might help him answer. In a harem society, is there a change in the zebras' interactions just before a bachelor overthrows a stallion in a coup? When zebras flee a lion, how do they decide which zebra will lead the stampede? Do different zebras play different roles in society? He rapidly hit a roadblock, however. Answering these questions required seeing how the interactions changed over time, but two zebras were connected in a graph if they had interacted at any time over a three-month season. The graphs didn't depict any of the changes in interactions within a season, so they couldn't answer the questions that most interested him. "It was like looking at the data with a very cloudy lens," Rubenstein says. "We were throwing away a lot of information, which was really frustrating." So he turned to Tanya Berger-Wolf, a computer scientist at the University of Illinois in Chicago, to find out how to analyze changing networks. She told him that the methods hadn't been developed yet. "If there's nothing else out there," she said, "I guess we'll have to do it." In August, Berger-Wolf and her collaborators received a $900,000 grant from the National Science Foundation for the project. First, Berger-Wolf is redefining the most basic concepts of network theory to make them work in a graph that reflects changes over time. Even the definition of a community has to be changed for dynamic networks. To take a very simple example, suppose that two zebras always hang out together, while a third is with them half the time. Is the third zebra a part of the group or not? If the third zebra joins the first two halfway through the study period, and then spends time with them consistently, we'd probably want to say yes. If the third zebra comes and goes, we might say no. She presented her new methods in August at the International Conference on Knowledge Discovery and Data Mining in San Jose, Calif.