1 . Smaller than African savanna elephants, forest elephants feed on grass, leaves and fruit. The rainforests of Gabon are one of the last strongholds for forest elephants, whose numbers have suffered a dramatic decline in recent decades because of hunting.
Despite being remote and relatively untouched by people, Lope National Park and its elephants appear to be in trouble. The fruity yield (产量) of many species of trees at the park continues to fall, which seems to be causing forest elephants to go hungry. Because certain tree species depend on the animals to survive, the struggles of the elephant population could jeopardize the long-term sustainability of the forest.
Known as an Omphalocarpum procerum, the tree is dotted with doughnut-shaped fruit growing out of its trunk. The fruit has a tough shell that makes it distasteful for every animal species except elephants. The tree relies on elephants to disperse (传播) seeds through their dung (粪) and grows stronger in elephant-populated areas. The tree is rarely found where elephants no longer live. The elephants, in turn, depend on the highly nutritious fruit for their diet.
A 32-year survey recorded an 81 percent decline in the availability of the fruits that elephants eat. Examining Lopvé’s weather data for the previous three decades, researchers found that the average nighttime temperature had increased by about 1.5 degrees. The amount of rainfall also had decreased significantly. Climate change was making Lope hotter and drier. Researchers think this is the most credible theory as to why fruit has been declining.
They also found that, on average, the body condition of forest elephants had declined by a pronounced 11 percent from 2008 to 2018. The scarcity of fruit in Lope was the likeliest explanation. The lack of fruit makes it harder for elephants to get the nutrition they need. Lope’s elephants try to make up for the fruit shortage by suddenly entering people’s gardens in the middle of the night.
At Lope National Park, scientists now are investigating whether climate change is changing the elephants’ diet. As they continue their research, they thought: Could the fraying of the ancient bond between trees and elephants in a place as pristine as Lopé be a forewarning?
1. What does the underlined word “jeopardize” in paragraph 2 probably mean?| A．Endanger. | B．Promote. | C．Achieve. | D．Ensure. |
| A．To state the effect of habitat loss on elephants. |
| B．To prove the importance of the species diversity. |
| C．To present the gradual process of forest decline. |
| D．To show the close relationship between the tree and elephants. |
| A．Frequent heavy rainfall. | B．The lack of fruit growers. |
| C．Inappropriate tree cutting. | D．The threat of climate change. |
| A．They visit human’s gardens for food. |
| B．They travel farther to search for fruit trees. |
| C．They start to eat other highly nutritious plants. |
| D．They carry fruit seeds to elephant-populated areas. |
2 . For humans, adapting to climate change will mostly be a matter of technology. More air conditioning, better-designed houses and bigger flood defenses may help lessen the effects of a warmer world. Animals will have to rely on changing their bodies or their behaviour. In a paper published inTrends in Ecology & Evolution, a team led by Sara Ryding, a professor in Australia, shows that is already happening. In some species of Australian parrot, for instance beak (喙) size has increased by between 4% and 10%since 1871. Similar trends are seen in species of mice and bats growing bigger ears, tails, legs and wings.
All that fits nicely with evolutionary (进化的) theory. “Allen’s rule”, named after Joe Allen, who suggested it in 1877, holds that warm-blooded animals in hot places tend to have larger appendages (附加物) than those in mild areas. Such adaptations boost an animal’s surface area relative to its body volume, helping it to get rid of additional heal. Fennec foxes, meanwhile, which are native to the Sahara desert, have strikingly large ears, especially compared with their Arctic cousins.
Ryding’s team combined data from different species in different places. Now that they have little in common apart from living on a warming planet, climate change is the most reasonable explanation. Since any evolutionary adaptation comes with trade-offs, it is unclear how far the process might go. Bigger beaks might interfere with feeding, for instance. Larger wings are heavier, and bigger legs cost more energy to grow.
Honestly, studying a broader range of animals will help firm up exactly what is happening. For now, at least, the increase is small, never much more than 10%. That may change as warming accelerates. Every little bit of avoided future temperature increases results in less warming that would otherwise stay for essentially forever.
1. Why do some species grow bigger parts of their body?| A．They are following the new trends. |
| B．They have to adapt to warmer climate. |
| C．Scientists need them to do experiments. |
| D．Larger parts tend to help them feed well. |
| A．In mild areas. | B．In hot places. |
| C．In the Arctic. | D．In deserted regions. |
| A．It comes at a cost. |
| B．Its cause is definite. |
| C．It happens in the same habitat. |
| D．Its process will end soon. |
| A．Living on a Warming Planet |
| B．Measures to Remove Heat |
| C．Pioneering Research on Animals |
| D．Evolution to Survive Heat |
