Despite the similar appearance to hyaenas(鬣狗), African wild dogs are without any doubt true wild canines(犬).The colour of their furs is a mixture of black brown, yellow, red and white. Those colours appear in so many different patterns that no two individuals look exactly alike. African wild dogs are often spotted across the African plains and spare woodlands, while they are seldom seen in jungle areas.
They are social animals, and normally hunt in groups of 6 to 20 individuals. There is a hierarchy (等级制度) existing within a group, as each group is mainly led by a pair of African wild dogs. However, the animals are friendly to one another, for the young and the weak are often assisted within the group.
African wild dogs mainly use their sense of sight to hunt for their prey. They can maintain a speed of about 40 km/h for about 5 kilometres. They usually hunt medium-sized antelopes, but they sometimes also attack larger animals such as calves, zebras and impalas.
Partly because of the increasing populations of human beings, the habitat of African wild dogs has been shrinking. In the meantime, the available prey is also largely diminished. Road kill and human hunting have also had a negative impact on its populations. The decrease of its populations is also related to the fact that this species is also susceptible to a variety of diseases carried by domestic dogs. As one of the world's most endangered mammals, the conservation of it should be carried out with a high priority.
It's hard to be a bird in the world dominated(支配)by human beings, as it's barely possible for you to hear yourself sing. Hearing the songs of your friends would be even more difficult, and you can just forget about hearing a predator approaching.
Noise is almost everywhere, especially from traffic. Lots of the landscape in the US is within just one kilometre of a road. Therefore, it is unsurprisingly to see researchers focus on the animals living near noisy roads when they evaluate the impact of road noise on animals." The problem is that noisy roads are both noisy, and at the same time, they are roads. It's hard to separate the two, "said a biologist who worked on this subject with his team. To make sure that there is just the noise without any other effect of the road, they ran speakers through a forest where there was no road. They then built an audio phantom road at a popular stopover spot for birds to fly south for the winter.
While lots of birds were kept away by noise, the researchers found that some birds just stuck around, because they lacked strength to support the next part of their migratory journey. To eat, the birds had to look down, meaning that they were not able to notice predators. And when there was too much noise, they couldn't hear the alarm calls of other birds. The two things were sadly in conflict with each other. So they had to waste time watching for predators instead of searching for food.
Road building is increasing worldwide. But there is an easy solution to the noise problem-lowering speed limits. So next time you are driving through nature, Just slow down a little It's safer for you and the wildlife. And you can enjoy the view a little longer.
Climate change is increasingly affecting our daily lives. Latest research and studies in the US highlight the facts about the human-caused change to our global weather systems and its effects on our planet. First among them is that rising temperatures and increasingly chaotic(混乱的)weather are the work of humanity. There's a 99.9999% chance that humans are the cause of global warming. Humans burn fossil fuels such as oil, coal and gas, which give out carbon dioxide(CO2), methane and other gases into Earth's atmosphere and oceans. CO2, is the greenhouse gas that's most responsible for warming.
Scientists worldwide have also conducted countless researches on this issue. For example, a group of scientists in Australia have published a study analysing the contributions to climate change by the worlds nations versus the effect that climate change will have on those countries.
They have found that some developed nations, such as Australia, the US and Canada, are essentially climate free riders, driving the problem of climate change while suffering relatively few of the costs, such as destructive flood, increased extreme weather and rising sea levels. Meanwhile, many countries in Africa or small island states which produce few greenhouse gas emissions are the most vulnerable(易受损害的) countries.
While it's important that this issue is defined by scientists, it needs to be acted on by global leaders. The Paris Agreement, finalised in December 2015, was widely seen as a positive step forward in addressing climate change. However, in order to help those vulnerable countries while achieving global emissions reductions, urgent and effective actions in accordance with the policies in the Paris Agreement must be taken.
Our planet is rich in life. Tigers and turtles, bats and bees, gnats and gnus, crabs and crabgrass -the list seems endless. We have named more than 1.5 million species, and suspect that millions more remain undiscovered. Scientists call this mind-boggling variety of life biodiversity. With so many species, it is surprising to realise that so many are in danger of becoming extinct.
Extinct species are plants and animals that once lived on Earth, but no longer live anywhere in the world. Endangered species are those most in danger of extinction. Even large populations of animals can be at risk. Passenger pigeons once darkened the skies of the US. Over time, habitat destruction and hunting decreased the population of these birds. The last one died alone at the Cincinnati Zoo in 1914.
Dinosaurs, dodos and passenger pigeons are all extinct. Extinction used to happen naturally, but in modern times, people have pushed wildlife to the brink much more quickly than ever before. We are losing wildlife very rapidly!
After realising this severe situation, many countries and international organisations have carried out rules and principles to protect endangered animals. The US Endangered Species Act of 1973, for example, was passed to protect threatened wildlife and habitats so they don't go the way of the dodo.
So why do animals become endangered? The main reason is the loss of habitats. Habitat destruction can make it extremely hard for wildlife to survive. However, as people learn to take better care of plants and animals as well as their habitats, endangered and threatened species may begin to make a comeback. In fact, many species such as bald eagles already have.
Plastic bottle is one of the daily wastes. Billions of plastic water bottles are thrown away every year, polluting land and waterways around the world. And this is causing a series of troubles around the world. Recently, scientists and product designers in the UK have found a possible solution.
They have managed to make an edible water bottle, that is, a water bottle that you can eat. They look more like bubbles, or small, round, clear balls. They can hold liquid inside. People who eat this bottle and drink with it for the first time may get surprised: the outside bursts in the mouth.
A member of the team explains that the outside, or the membrane of this bottle is made of the brown seaweed, a plant that grows in the ocean It is tasteless but safe to eat. And, as the team has claimed, even if you throw. It away, it will degrade in about four weeks, doing no harm to the environment.
It cannot be refilled, and each bottle is quite small. What's more, they can store liquid for only a few days. But the number will soon increase to hundreds of thousands with the development of new technology.
A. The typical water bottle made of plastic can take hundreds of years to degrade.
B. But there are limits to this new form of bottle.
C. The seaweed can contain water or any kind of liquid.
D. Unlike plastic bottles, the newly invented bottles are not tall or hard.
E. The team is currently working on solving these Issues.
F. Right now, people can make only a few thousand of such bottles a day.
G. According to him, the membrane can contain water or other kinds of liquid
My previous home had a stand of woods behind it and many animals in the backyard. That first year, I1feeding peanuts to the blue jays, then the squirrels. The squirrels had no2coming up right to me for them. As the months went by, the rabbits saw that I was no3and didn't escape. When I threw carrot slices to them, they even came for a nibble(一小口). Slowly they came to4me, and by the end of the year they were eating out of my hand.
That second year, the rabbits5me, and one would even sit up for slices! While I was feeding them, I6that a groundhog who used to run away was now taking an7interest in this food situation. I carefully extended a long8, with a keen eye on those teeth, and9, there were times I would have the groundhog sitting next to a rabbit, both munching(用力嚼)on carrots. A few months later, while10, she would even tum her back to me. 11when she was facing away, I reached out and 12scratched(挠) her back with my finger. She didn't move.
By year three, the rabbits and the groundhog were back. The groundhog13didn't have a problem with me scratching her back, and I got an idea. I'd always14. While slicing up carrots, that the end of the carrot looked like a cap.15one day, just to see what she would do, I gently 16one on top of the groundhog's head. Again, not a17. The next time, I had my camera ready to record what I see here, one of several dozen such pictures.18she had a slice to eat. She never19with the one on her head. It was a fair 20—I got a pleasure, and she had yet another tasty treat.
According to the current research in Canada, data centres and smart phones will be the most damaging information and communication technology (ICT) to the environment by 2040. The researchers claim that ICT will account as much as 14% for the total (globe) footprint by 2040.Among all the devices, they predict that by 2020, the most (damage) ones to the environment are smart phones. smart phones consume little energy to operate, over 80% of their emissions impact (come) from their production. The chip and the motherboard of a smart phone are made up of precious metals which are mined at a high cost. Therefore, (produce) them requires huge amount of energy. Smart phones also have a relatively shorter life, drives further production of new models and extraordinary amount of waste.
With the (late)research, the researchers hope to help smart phone users expand worldview. When selecting and purchasing smart phones, many people don't consider the issue of sustainability. The researchers hope that through their work, they could help people realise what they want to do.
