작성일 : 20-07-14 18:02
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송수빈 (218.♡.28.57)
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however, some animals will survive by forcing themselves to modify their behaviors or adapt new ones to lower their risk of predation. this changes in behavior occur due to the increase of risk of predation and are called predation risk effects. um this risk effects also exert major influences on the eco system on the eco system. um professor I get the concept of predation risk effect but I'm having a hard time visualizing this risk effect on the eco system is there a real world example that you maybe tell us about? of course i'm sure many of you went on a school trip to yellowstone national park last year. well for those of you who didn't get a chance to visit, um yellowstone national park was established by congress in 1872. it's primary purpose was to protect not only the landescape, but also go wildlife that inhibited the region. in the beggining however the partion was only limited to specific types of animals. for example, carnivores were not protected at the time and with the exception of bears or continually hunted over the next course of few decades. as a result of this peculiar regulation those by the government wolves, 코요테, large cats and other carnivores, could be freely hunted not surprisingly by 1926. the wolves in the park have been wiped out so what do you think happened in the park? as a result of the dissaperrance. well I guess since the thread of wolves was no longer present. the animals that wolves thread upon lied in their population increase. you're right in this case elk a type of large dear were one of the animals that wolves preyed on most. so i read out of the wolves their range of activity increased dramatically in addition to that something else increased in volume as well anybody want to take a guess? well elk are herbivores so they feed on plants right?as you mentioned previously, they most likely started living and roaming without fear, I'm guessing their range of food also expanded along with their activity/
you got it unfortunately seedlings of aspans were the elk's main food source and they devoured them all around the park, including where elks had never been present before because of the presence of the wolves. this meant that the seedlings never got the chance to mature into trees trees correct me if I'm wrong professor but doesn;t the decrease in the number of the trees also mean that birds and other pecies that rely upon them as a means of survival were also negatively affected?
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