晚练册 第7周-【晨读晚记】2023-2024学年高三上学期英语阅读强化训练

Week Seven 第7周 晚练 的阅读理解A Squirrels eavesdrop on (the chatter of songbirds to work out whether the appearance of a predator is cause for alarm,researchers have found.Animals including squirrels have previously been found to tune in to cries of alarm from other creatures. But the latest study suggests animals may also keep an ear out for everyday chitchat among other species as a way to assess whether there is trouble afoot. Writing in the journal Plos One,researchers reported on how they made their discovery by observing 67 grey squirrels as they pottered about (different areas in the residential regions of Oberlin. After 30 seconds of observing a squirrel,researchers played it a recording of the call of a red-tailed hawk(). which lasted a couple of seconds-and their behaviour in the next 30 seconds was monitored.The squirrels were then played a three-minute recording of several different species of songbird chattering on a feeder. The results revealed that in the 30 seconds after hearing the hawk call the squirrels increased the percentage of their time spent"vigilant()"compared with before the call,while they also looked up more often to scan the environment.Squirrels that were played bird chatter raised their heads less often during the recording and the number of these"look-ups"dropped off faster over time. "Recognition of bird chatter as a sign of safety is likely adaptive,as squirrels that can safely reduce their vigilance level in the presence of bird chatter probably are able to increase foraging (success,"the authors wrote. The team suggested that with levels of human-made noise increasing,squirrels may find it harder to eavesdrop on birds,meaning they may have to spend more time being alert and less time foraging. Dr Jakob Bro-Jorgensen,co-author of the study from Oberlin College,said:"The study calls attention to how animals can gather information from their environment by using cues that may at first glance seem irrelevant,,”he said.“And it makes you won