Behavior Under Risk: How Animals Avoid Becoming Dinner By: Renee L. Rosier & Tracy Langkilde © 2021 Nature Education Most animals face the risk of being eaten. To avoid becoming someone’s dinner, an organism must be able to identify predatory threats and employ effective strategies to avoid detection by predators. In the event that avoidance fails, animals can use strategies that will increase their chances of surviving attack if they do encounter predators. Detecting predators a. Visual — Many animals respond to general visual cues, such as the presence of a new object or sudden movement. Other visual cues, including an animal’s size and behavior, can provide specific information about the identity and intention of a potential predator. For example, prey may be able to visually identify a predator based on its shape, size, and color, and can use the predator’s behavior to determine the immediate threat that it poses. b. Auditory — Auditory cues can provide reliable, direct information about a predator’s presence, identity. These cues are especially helpful for nocturnal prey species or animals that avoid predators that frequently use sound to hunt or communicate. For example, toadfish recognize sound of dolphins when they are looking for food, one of their main predators, and reduce their activity levels in response. c. Chemical — Chemical cues can be present in the air, in water, or on the ground, and can be detected by prey through olfaction and gustation, providing a reliable indication of a predator’s presence even if it is visually undetectable. Some species are even able to determine how old a predator scent is, and will avoid only fresh scent cues as they indicate a predator’s recent presence. Animals can also use changes in the concentration or age of a scent to determine which direction a predator was traveling, in order to better avoid it. d. Vibration — Vibration cues can provide useful information about a predator’s presence, and can be difficult for predators to conceal. Many animals, including some spiders, caterpillars, and tadpoles, use vibrations as indicators of predator presence, and can distinguish vibrations made by predators, non-predators, and abiotic cues (such as rainfall). It is important for prey to be able to distinguish cues from threats versus non-threats, as responding to every tactile stimulus would waste time and energy, and may actually attract the attention of predators. |
| A．Visual. | B．Auditory. | C．Chemical. | D．Vibration. |
| A．Visual cues can be used as an indication of predators’ intention. |
| B．Chemical cues fail to function if the predators are out of sight. |
| C．Auditory cues help prey to figure out what kind of predators they meet. |
| D．Vibration cues are reliable as predators can hardly stop vibrating. |
| A．Surviving Encounters with Predators. | B．Effective Ways to Find out Predators. |
| C．Distinct Characteristics of Predators. | D．Prey species and their behaviors. |
2 . The population of rare Atlantic puffins in Maine, US, took a hit this year, as the number of chicks to survive a tough summer collapsed. The state's coastal bays and the Gulf of Maine are among the fastest warming large water bodies on the planet, making the puffins' fate a test-case for how climate change could disrupt marine ecosystems worldwide.
The little clown-colored birds faced a complex of challenges: nests were flooded by some of the heaviest rains in a hundred years, exposing chicks to cold and predators. It was tough for young puffins, who were being brought up in caves along the island's shores. And their parents had a hard time finding herring (鲱鱼) and other North Atlantic prey they usually dive for, which scientists think may have swum to cooler waters too deep or far-off for the birds. The adult puffins flew farther than usual to find food. Scientists say this limited their time to keep baby puffins warm in their nests. They did find and bring to the nests a lot of butterfish, but the thing is that butterfish are too big for young puffins to swallow.
The director of the National Audubon Society's Seabird Institute, Don Lyons, says puffins provide a unique window on global warming, on how even small shifts in the range or timing of any one species' occurrence can influence the fate of many others. "Working with puffins in Maine, we're seeing the harbingers (预兆) of climate change every day," he said. "I tend to think of puffins as a group of researchers. They're going out and sampling our marine ecosystem all summer, many times a day. And the way we learn from them is watching what fish they bring back and how well they are able to raise baby coffins. ... They're really telling us to be concerned, you know, to pay attention."
Lyons says that with good management of herring and other fisheries that the puffins depend on, the birds should be able to hang on. Puffins can live up to 30 years and this means it won’t be too terrible if they meet only a bad year. He adds, though, that their future in Maine may depend on just how often those bad years keep rolling in.
1. The phrase “took a hit” (in the 1st paragraph) probably mean “________”.| A．suffer heavy losses | B．escape bad fortune |
| C．increase on a large-scale | D．decline moderately |
| A．Puffins’ nests are open to the attack of their predators. |
| B．Baby puffins are not adequately fed. |
| C．Puffins’ prey prefers to stay in warm waters. |
| D．Butterfish are not the appropriate food for baby puffins. |
| A．puffins are helping human to maintain marine ecosystem |
| B．we can tell the marine ecosystem from what puffins do |
| C．puffins are more capable of diving for their prey |
| D．it’s interesting for researchers to work with puffins |
| A．the control of puffins’ population |
| B．prohibition of fishing herring and other fish |
| C．puffins’ abilities to adapt to different marine ecosystem |
| D．the frequency of the continuous occurrence of bad year |
| A．She joined a free fitness programme. |
| B．She never persevered in going to the gym. |
| C．The trainer offered to help her for free. |
| D．Her friend recommended her to do so. |
| A．She is overweight. | B．She often overworks. |
| C．She is not fit enough. | D．She has a bad lifestyle. |
| A．By setting a role model himself. |
| B．By giving her personalized advice. |
| C．By working with her in a funny way. |
| D．By running and jumping with her. |
| A．Manageable. | B．Unrealistic. |
| C．Dull. | D．Demotivating. |
| A．Low sleep efficiency. | B．Human evolution. |
| C．A psychological disease. | D．An unusual brain disorder. |
| A．They can hardly fall asleep all night. | B．Their brains don’t function well. |
| C．They have terrible dreams. | D．Their brains remain awake. |
| A．Ways to improve sleeping quality. | B．Surroundings and sleeping quality. |
| C．Treatment for the first night effect. | D．How the two parts of the brain work. |
| A．It doesn’t include a remote. | B．It can be controlled by gesture. |
| C．It can automatically power off. | D．It can be operated by voice. |
| A．Much to be improved. | B．Not as good as expected. |
| C．Good enough at its price point. | D．Best of all the TVs. |
| A．A fantastic video clip. | B．An introduction of a review channel. |
| C．A comment on a TV. | D．The usage of a remote. |
| A．Narrow down his theme. | B．Revise his paper carefully. |
| C．Focus on the paper. | D．Cover more topics. |
| A．Have a rest. | B．Learn new skills. |
| C．Find a new job. | D．Do extra work. |
假设你的朋友John作为交换生要来一所中学学习一年。现在有两个家庭可为他提供住宿。John对如何选择犹豫不决，想听听你的建议。请根据以下住宿家庭信息，写一封email给John，说说你推荐哪个家庭，并简要谈谈这样推荐的理由。
| 王先生家庭 | 李先生家庭 | |
| 家庭成员 | 一对中年夫妇；一个17岁的男孩 | 一对退休夫妇 |
| 住宿条件 | 提供一个带独立卫生间的房间 | 提供一个无独立卫生间房间 |
| 伙食 | 周一至周六提供早餐和晚餐，周日不提供餐饮 | 周一至周五提供早餐和晚餐；周六和周日提供三餐 |
| 距学校距离 | 地铁大约一小时车程 | 步行到学校大约10分钟 |
