雄性黑寡妇能嗅出雌性饥饿程度-凯发k8官网

雄性黑寡妇能嗅出雌性饥饿程度
文章来源:未知 文章作者:enread 发布时间:2011-07-07 07:47 字体: [ ] 
(单词翻译:双击或拖选)

male black widow spiders can 1 out a well-fed female simply by walking on her web, according to researchers.

研究人员称,雄性黑寡妇蜘蛛只需行走在雌性黑寡妇织的网上就能嗅出其是否吃饱。

the female black widow spider is much larger than the male
the female black widow spider is much larger than the male

the males appear to use this technique to avoid hungry females, which are more likely to cannibalise(自食生存) them.

this habit of eating the male after mating earned the spiders their name.

but this research shows that males can 2 that risk by 3 the silk to find out if a female is 4(贪婪的,渴望的) and therefore too 5 to mate with.

the study is published in the journal animal behaviour, and is the first to show that the spiders are able to pick up "chemical cues" from each others' silk.

james chadwick johnson from arizona state university, us, who led the study, hand-fed female black widow spiders to make sure he had a well-fed group of females for the experiment.

"6 speaking, it was forcep-feeding," he told bbc nature. "we held a cricket in the forceps(钳子) and left it sitting on the female's web. eventually the female would run over and start throwing silk and wrapping up the cricket."

the team gave these females one cricket per week.

"by the fourth week, it was difficult to convince her to eat it," he said. "but we wanted to get as much cricket into her as possible."

the other group of females in the test were starved for several weeks. this did not endanger their lives, but they were "visibly smaller".

in the test, the researchers placed male spiders onto the different females' webs to see how they would react.

to make sure the males were only taking cues from the female spiders' silk, they also put males onto a small bundle of clean silk - with no 7 from consumed 8 - taken from the webs of both well-fed and hungry females.

"we also 9(交换) the females," recalled professor johnson, "tricking the male into thinking he was with a starved female when he was with a well-fed one."

the male spiders, which pick up 10 through their feet, were able to tell the difference just by walking on the silk. they carried out their typical courtship(求爱,求婚) dance much more 11 when they were on the silk of a female who had been force-fed on an ample(丰富的) diet of crickets.

"this courtship display is a long drawn-out process," explained professor johnson. "before the male mounts the female, he will spend an hour or two walking around plucking and tapping the web.

"it's like spider tai chi; by waving his legs and plucking, he's providing 12 that are very distinct to tell the female, 'i am not a prey item'.

"this continues until he eventually climbs onto the 13(腹部) of the female. then he'll transfer 14 and get out of town as quickly as possible."

one aim of professor johnson's studies of spider behaviour is to understand more about animals, including spiders, that share our urban, human-dominated environment.

he told bbc nature: "we change the world like no other species and so it seems to me the 15(责任,义务) is on us to understand what happens when we change environments.

"it's not just an 16(利他的) goal either. for example, we are finding a lot of 17 in urban 18(感染,侵扰) of widows compared to desert populations and understanding this... could tell us whether a population is likely to grow or not."



点击收听单词发音收听单词发音  

1 pf7zs     
vi.嗅…味道;抽鼻涕;对嗤之以鼻,蔑视
参考例句:
  • the police used dogs to sniff out the criminals in their hiding - place.警察使用警犬查出了罪犯的藏身地点。
  • when munchie meets a dog on the beach, they sniff each other for a while.当麦奇在海滩上碰到另一条狗的时候,他们会彼此嗅一会儿。
2 ejryf     
vt.(使)减轻,(使)缓和
参考例句:
  • the government is trying to mitigate the effects of inflation.政府正试图缓和通货膨胀的影响。
  • governments should endeavour to mitigate distress.政府应努力缓解贫困问题。
3 50b6416c50a7d3793e6172a8514a0576     
n.探查法v.以鼻吸气,嗅,闻( sniff的现在分词 );抽鼻子(尤指哭泣、患感冒等时出声地用鼻子吸气);抱怨,不以为然地说
参考例句:
  • we all had colds and couldn't stop sniffing and sneezing. 我们都感冒了,一个劲地抽鼻子,打喷嚏。
  • they all had colds and were sniffing and sneezing. 他们都伤风了,呼呼喘气而且打喷嚏。 来自《现代英汉综合大词典》
4 iazz8     
adj.极饿的,贪婪的
参考例句:
  • the ravenous children ate everything on the table.饿极了的孩子把桌上所有东西吃掉了。
  • most infants have a ravenous appetite.大多数婴儿胃口极好。
5 ixvxe     
adj.有风险的,冒险的
参考例句:
  • it may be risky but we will chance it anyhow.这可能有危险,但我们无论如何要冒一冒险。
  • he is well aware how risky this investment is.他心里对这项投资的风险十分清楚。
6 gtnwe     
adv.严厉地,严格地;严密地
参考例句:
  • his doctor is dieting him strictly.他的医生严格规定他的饮食。
  • the guests were seated strictly in order of precedence.客人严格按照地位高低就座。
7 debris     
n.瓦砾堆,废墟,碎片
参考例句:
  • after the bombing there was a lot of debris everywhere.轰炸之后到处瓦砾成堆。
  • bacteria sticks to food debris in the teeth,causing decay.细菌附着在牙缝中的食物残渣上,导致蛀牙。
8 g1czh     
n.被掠食者,牺牲者,掠食;v.捕食,掠夺,折磨
参考例句:
  • stronger animals prey on weaker ones.弱肉强食。
  • the lion was hunting for its prey.狮子在寻找猎物。
9 3982604ac592befc46570aef4e827102     
交换(工作)( swap的过去式和过去分词 ); 用…替换,把…换成,掉换(过来)
参考例句:
  • i liked her coat and she liked mine, so we swapped. 我喜欢她的外套,她喜欢我的外套,于是我们就交换了。
  • at half-time the manager swapped some of the players around. 经理在半场时把几名队员换下了场。
10 9d41e056b814c700bf06c9870b09a332     
n.香水( scent的名词复数 );气味;(动物的)臭迹;(尤指狗的)嗅觉
参考例句:
  • the air was fragrant with scents from the sea and the hills. 空气中荡漾着山和海的芬芳气息。
  • the winds came down with scents of the grass and wild flowers. 微风送来阵阵青草和野花的香气。 来自《简明英汉词典》
11 lzezni     
adv.积极地,勤奋地
参考例句:
  • during this period all the students were actively participating.在这节课中所有的学生都积极参加。
  • we are actively intervening to settle a quarrel.我们正在积极调解争执。
12 d94a4ca3e6fa6302ae79121ffdf03b40     
n.摆动( vibration的名词复数 );震动;感受;(偏离平衡位置的)一次性往复振动
参考例句:
  • we could feel the vibrations from the trucks passing outside. 我们可以感到外面卡车经过时的颤动。
  • i am drawn to that girl; i get good vibrations from her. 我被那女孩吸引住了,她使我产生良好的感觉。 来自《简明英汉词典》
13 mfxym     
n.腹,下腹(胸部到腿部的部分)
参考例句:
  • how to know to there is ascarid inside abdomen?怎样知道肚子里面有蛔虫?
  • he was anxious about an off-and-on pain the abdomen.他因时隐时现的腹痛而焦虑。
14 jfozo     
n.精子,精液
参考例句:
  • only one sperm fertilises an egg.只有一个精子使卵子受精。
  • in human reproduction,one female egg is usually fertilized by one sperm.在人体生殖过程中,一个精子使一个卵子受精。
15 zvly4     
n.负担;责任
参考例句:
  • the onus is on government departments to show cause why information cannot bedisclosed.政府部门有责任说明不能把信息公开的理由。
  • the onus of proof lies with you.你有责任提供证据。
16 hzuza6     
adj.无私的,为他人着想的
参考例句:
  • it is superficial to be altruistic without feeling compassion.无慈悲之心却说利他,是为表面。
  • altruistic spirit should be cultivated by us vigorously.利他的精神是我们应该努力培养的。
17 ztgye     
n.同类相食;吃人肉
参考例句:
  • the war is just like the cannibalism of animals.战争就如同动物之间的互相残。
  • they were forced to practise cannibalism in order to survive.他们被迫人吃人以求活下去。
18 ace083e6dba5b9eb0980e4990eee3074     
n.(害虫、盗贼等)群袭,出没,横行( infestation的名词复数 )
参考例句:
  • the arrival of warm weather raises the specter of disease and increased rat infestations caused by rotting garbage. 天气转暖使人们担心垃圾腐烂会引起疾病传播和鼠群猖獗。 来自《简明英汉词典》
  • piperazine citrate is the drug of choice in the treatment of ascaris infestations. 枸橼酸哌嗪治疗蛔虫感染是最好的药物。 来自辞典例句
tag标签: female widow sniff
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