版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领
文档简介
1、DolphinsDolphin Dolphins are marine mammals closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, eating mostly fish and squid. Rissos Dolphinbottlenose d
2、olphinOrcaKiller WhaleCommersons dolphin Dusky dolphin Indo-Pacific hump-backed dolphin Sousa chinensis BehaviorIntelligence Dolphins are often regarded as one of Earths most intelligent animals, though it is hard to say just how intelligent. Comparing species relative intelligence is complicated by
3、 differences in sensory apparatus, response modes, and nature of cognition. Social behaviorDolphins are social living in pods of up to a dozen individuals. In places with a high abundance of food, forming a super grouping may exceed 1,000 dolphins. Dolphins can establish strong social bonds; they wi
4、ll stay with injured or ill individuals, even helping them to breathe by bringing them to the surface if needed. Sleeping Generally, dolphins sleep with only one brain hemisphere in slow-wave sleep at a time, thus maintaining enough consciousness to breathe and to watch for possible predators and ot
5、her threats. Vocalizations Roughly three categories of sounds can be identified: frequency modulated whistles burst-pulsed sounds clicks. Dolphins communicate with whistle-like sounds produced by vibrating connective tissue, similar to the way human vocal cords function and through burst-pulsed soun
6、ds.Jumping Dolphins occasionally leap above the water surface, and sometimes perform acrobatic figures. Scientists are not certain about the purpose of the acrobatics. Possibilities include locating schools of fish by looking at above-water signs like feeding birds, communicating with other dolphins
7、, dislodging parasites or simple amusement.Playing Play is an important part of dolphin culture. Dolphins play with seaweed and play-fight with other dolphins. At times they harass other local creatures, like seabirds and turtles. Relationships with humansMythology Dolphins have long played a role i
8、n human culture. Dolphins are common in Greek mythology and there are many coins from ancient Greece which feature a man or boy or deity riding on the back of a dolphin. Friends of humans Dolphins are friends of human beings, they are happy to be with people. Assist fishermen fishing; Have many repo
9、rts about dolphins to save people; One report in 1959,even said that dolphins drove sharks away, then saved the victims of the passengers. Therapy Therapy for psychological problems and developmental disabilities. For example, a 2005 study found dolphins an effective treatment for mild to moderate d
10、epression. Militaryfinding minesrescuing lost or trapped humansCuisine Dolphin meat is consumed in a small number of countries world-wide, which include Japan and Peru.ThreatsHuman threats Some dolphin species face an uncertain future, especially some river dolphin species such as the Amazon river d
11、olphin, which are critically or seriously endangered. Natural threats Except for humans, dolphins have few natural enemies. A few of the larger sharks, such as great white sharkA wide variety of diseases and parasitesPollutionPesticides Heavy metalsPlasticsIndustrial and agricultural pollutants nois
12、e Loud underwater noises, such as live firing exercises, or certain offshore construction projects, such as wind farms, may be harmful to dolphins, increasing stress, damaging hearing, and causing decompression sickness by forcing them to surface too quickly to escape the noise.Hunting Various fishing methods, the use of drift and gill nets,
温馨提示
- 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
- 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
- 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
- 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
- 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
- 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
- 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
最新文档
- GB/T 43908-2024水肥一体化设备
- 公司合作技术保密协议模板
- 员工录用劳动合同样书
- 2023年4月自考28050学前教育研究方法试题及答案含解析
- 《销售管理》 教案 01销售概述
- 推土机寻沾高速机械设备安全技术交底
- 吉林省松原市宁江区2023-2024学年八年级下学期期中语文试题
- 2024年广西柳州市中考语文三模语文试题
- 兴趣班活动总结6篇
- 湖南省怀化市锦江中学高一英语联考试卷含解析
- 2024年1月安徽省普通高等学校招生考试适应性测试物理试题(原卷版)
- 化妆品(原料)安全性风险评估
- 2024年中国钢研科技集团有限公司招聘笔试参考题库含答案解析
- 营养土创业计划书
- 委托人力资源招聘筛选服务协议
- 煤矿环境保护知识讲座
- 2024年运维软件行业市场研究报告
- 夜班工作的工作保障与紧急处理
- 《中国民族音乐》课件
- 小学教育课件教案音乐能治愈:了解音乐疗法的有效性
- 高速公路交通事故调查组成立 抓紧核查处理
评论
0/150
提交评论