标签：探索发现 相关文章
Meanwhile, the ground sloth, like the mastodons, must eat most of the day to fuel its huge bulk. This may be the ice age, but by midday, temperatures soar, drawing another predator to the spring to drinkthe notorious saber-toothed cat. Most creatures
探索与发现2013年
Today, there is a group of larger visitors here, too. A herd of mastodons led by the matriarch have just returned from their annual migration hundreds of miles to the north. Now the winter drought is over and the spring water has been topped up by re
探索与发现2013年
Some of this ice age dung was found beneath the skull in the Aucilla. The dung contained plant remains that tell us what the mastodon was browsing on 13,000 years ago or morea mixture of trees and grasses. This suggests that ice age Florida was drier
探索与发现2013年
They can grow more than two metres long and weigh as much as three men. But the giant tortoises of ice age North America were even larger. Florida does have tortoises today, but on a much smaller scale. This is the gopher tortoise. Tortoises are cold
探索与发现2013年
It's likely giant ground sloths used their claws in a similiar way to hook branches and pull them within reach. Like tree sloths, they were vegetarians and probably not fussy about what they ate, chewing their way through leaves, fruits, twigs and al
探索与发现2013年
This is the Virginia opossum, a tree dweller found throughout many of the southern states. It's the only North American marsupial. The young are born premature and matured in the mother's pouch. And its only close relatives today are found in Central
探索与发现2013年
For the monasteries were still producing great works of art. He might have been less enamoured at the political maneuvering. The status of clergy could have much to do with their alliances and family ties with the local aristocracy. Indeed, from the
探索与发现2012年
Next, America's sex pioneers. Stories about how sex help found our nation and shaped our history. Ben Franklin and the French set it up. The puritans get down and dirty. A heavy-weight champ fights for his life. And sex super charges the auto industr
探索与发现2014年
Another founding principle of America history has been ingenuity. What would sex inspire you to invent? I manna invent a pill that would make you to have sex all of the time. I would invent something that got him up and ready to go at a moment *. I t
探索与发现2014年
But not everyone was interested in following their puritans' strict rules, especially when it came to sex. -Amist of these puritans' colonies, along came a very charismatic and interesting libertarian by the name of Thomas Morton, who started up a co
探索与发现2014年
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探索与发现2015年
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探索与发现2015年
Where purple martins had once laid their eggs in hollow threes, in time, they came to rely almost totally on people to provide nests for them. These artificial nests were made from dried out squashes known as gourds. The shape made them perfect nesti
探索与发现2013年
At first, the Europeans relied heavily on local food supply by native people. But as they settled in, their farming practices began to shape the landscape of North America. The plow allowed them to farm larger areas of land, helping to feed the expan
探索与发现2013年
And farming fuelled the growth of another habitat, one that would become an even bigger challenge to North America's wildlife. The modern city was born. The city is an artificial environment, built around the needs of millions of people, and yet it a
探索与发现2013年
The owls can raise anything from 1 to 12 chicks in a summer season. To survive, their young will have to quickly learn to negotiate the dangers of city life. Longer hunting trips are sometimes necessary as open land disappears. But so long as the cit
探索与发现2013年
Although many of these city foxes do get killed by cars, the population as a whole is thriving. Thats because a regular supply of water means a regular supply of prey, including voles and ground squirrels. Playing on the streets at night is dangerous
探索与发现2013年
Moose mainly browse on trees and shrubs, but they will also sample something new. They have a soft spot for pumpkins left out after Halloween. As many as 1,000 moose may enter Anchorage in winter, snowfall here is lower than its surrounding hills and
探索与发现2013年
This disused car park is a near-perfect location for raising chicks, and only a short flight from a plentiful supply of food. Skimmers get their name from their unusual feeding technique--their extended lower bill detects fish just below the water su
探索与发现2013年
This mass roosting takes place soon after the summer nesting season. Its a chance for the birds to molt before they fly south for the winter. As Vauxs swift numbers reach a peak in mid September, they attract attention from the locals. Coopers hawks
探索与发现2013年