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Q. Dear Twig: Do reindeer really play games? A. Reindeer play but not real games. They start when they’re young. They chase each other. They jump up and down. They do things called mutual threat displays. That means they scowl and shake fists at each other. Except they don’t have fists. No, they don’t play games with scores or uniforms or Yukon Cornelius driving them to practice in a minivan. He drives a dog sled anyway. But reindeer play has a serious purpose. It lets them practice things they’ll need to know how to do when they’re grown-ups. Like warning the herd of danger. Getting away from danger (such as a wolf). And fighting to not get eaten or win a mate. How, in fact, does a reindeer warn of danger? It jumps in the air — what scientists call an excitation leap — and then runs away. All of the other reindeer see the leap, see the running, and take off running, too. Provided they learned the drill as calves. Know what that reindeer, the eagle-eyed spotter of danger, does first ofall before leaping? A book called Mammalian Social Learning tells us. It “looks directly at the source of disturbance and spreads its hind legs, usually also urinating.” Whoa. I’m pretty sure Rudolph didn’t do that. Could be why the Bumble caught him.  Behaviorally, Twig For details, to ask Twig a question, and/or to receive the column free by mail or e-mail, contact Kurt Knebusch, CommTech, OSU/OARDC,1680 Madison Ave., Wooster, OH 44691, knebusch.1@osu.edu, 330-263-3776. |
Trees take to the streets
Bristlecone pine trees grow in California's White Mountains. They are thousands of years old--and are some of the oldest trees in the world.
Most trees aren't this hardy. In the country, a tree might live 150 years. But in the city, a tree might live for only 10 years--or even less! That's because city trees have to deal with a lot of stress. The sources of that stress include air pollution, bad weather, insects, busy streets, and power lines.
All the things that people don't like about cities--guess what? Trees don't like them, either!
But we need trees in our cities. So scientists have developed special varieties of trees that can handle life on the mean streets.
John Hammond works at the U.S. National Arboretum in Washington, D.C. He and other USNA scientists put together a team with scientists from other local, regional, and national groups to see if they could figure out how to give trees a needed boost.
They wanted attractive trees. They wanted trees that wouldn't grow too big for their neighborhoods. They wanted trees that could stand up to having their roots walked on--over and over again. They wanted trees that could shrug off pests such as insects. One such pest is a metallic-green beetle, called the emerald ash borer, that feeds beneath the bark of green, white, and black ash trees. Since its discovery near Detroit in May 2002, borer infestations have destroyed the ash tree population in parts of Michigan and also threaten parts of Ohio and Ontario.
Hammond and the other scientists looked at trees that had already been developed at USNA. These trees already had their "family tree" on record. So the scientists went looking for the trees that already had the characteristics they wanted in their city trees.
For instance, if all the grownups in your family are over six feet tall, there's a pretty good chance that you'll grow to be six feet tall, too.
The team worked for over four years, and selected several different trees that met their goals--like this robust red maple.
These trees won't grow so tall that they bump into power lines. Their branches are sturdy enough to stand up to strong windstorms. Their foliage protects birds and other urban wildlife.
And in the spring or in the fall, their blossoms and bright leaves add color and contrast that the Public Works Department doesn't have to set up and take down!
A tree grows in DanversOnce there was a pear tree. It lived in Danvers, Massachusetts, about 20 miles north of Boston. The governor himself had planted it. The governor's name was John Endicott, and he liked to grow fruit trees when he was not busy governing the state. This was in the 1630s. In the 1630s, Massachusetts wasn't part of the United States of America; it was one of England's colonies. But the Endicott pear tree was still alive in 1776, when the colonists declared independence. It was still alive when the people of the United States elected as president John Adams and John Quincy Adams and John F. Kennedy and George Herbert Walker Bush--all born in Massachusetts. The pear tree was alive in 1969, when United States sent the first astronauts to walk on the moon. And in 2004, when the Boston Red Sox won the World Series for the first time in more than 80 years, the tree was still there. In fact, it's still alive and bearing fruit today. You can visit it in Massachusetts and see the pears. Today, John Endicott's pear tree is almost 400 years old. It's probably the oldest cultivated fruit-bearing tree in the United States. "Cultivated" means cared for by humans, as opposed to growing wild. As you might guess, it's also very hardy. We say a plant is "hardy" when it survives really difficult conditions. What difficult conditions did the tree survive? Sometimes people forgot to take care of the tree. They didn't water it, prune it, or protect it from insects, but the tree kept growing and producing fruit. In 400 years, the tree survived some very big storms. Hurricanes stripped the leaves off its branches and shook its fruit to the ground. In 1934, a huge storm shattered the tree's branches and twisted its trunk. But the tree grew back. Then something terrible happened. In 1964, vandals hopped the wooden fence that protected the tree. They sawed off all the branches and then cut the trunk off 6 feet above the ground. That kind of damage would kill a lot of trees. But the pear tree grew back again and started making fruit, just as it had since the 1630s. That's why we say it's a very hardy tree. The Endicott pear tree has a lot of relatives. How do we know? One way to make a copy of a woody plant--like a tree or a shrub--is to take a bud or shoot from an existing tree and connect it to the roots of another plant. "This is called "grafting," and the new grafted plant is a clone of the old tree. A clone is an exact copy of something. People have made many grafts from the Endicott pear tree, so it has relatives or clones growing all over the United States. One of those trees grows in Corvallis, Oregon, at the National Clonal Germplasm Repository. The NCGR is a place that stores seeds and plants of different fruit crops from around the world. In addition to the Endicott pear, it has more than 1,000 different pear varieties from more than 50 countries. Why do we need so many pears? Each kind of pear has different genes. Genes are short pieces of DNA, which tell a living thing--such as our bodies--to make proteins. These proteins affect how we look and behave. All living things, from pears to people, have genes. All pears have a few genes in common, just like you have a few genes in common with the people in your family. But every kind of pear is different, just like all the people at your school are different. Some pears are tastier than others. Some grow better where the weather is cold, and others grow better where the weather is warm. "It's important to store all of these different genes so that we can protect the pears," says Joseph Postman. He's a curator for the Agricultural Research Service at the NCGR. A curator is somebody who looks after things, often in a museum. In addition to pears, the NCGR holds seeds and other materials for thousands of varieties of nuts, berries, mints and other tasty crops. It's an important job, because it guarantees that we'll be able to grow those foods when we need to... maybe even 400 years from now. If something like plant disease or environmental change kills a lot of plants, we'll be able to grow new ones with seeds and grafts. For a task like that, a hardy plant like the Endicott pear would be really handy. |
 
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