<tt id="6hsgl"><pre id="6hsgl"><pre id="6hsgl"></pre></pre></tt>
          <nav id="6hsgl"><th id="6hsgl"></th></nav>
          国产免费网站看v片元遮挡,一亚洲一区二区中文字幕,波多野结衣一区二区免费视频,天天色综网,久久综合给合久久狠狠狠,男人的天堂av一二三区,午夜福利看片在线观看,亚洲中文字幕在线无码一区二区
          您現(xiàn)在的位置: > Language Tips > Easy English > Odd Question  
           





            Why do deer shed their antlers?
          [ 2006-02-21 08:07 ]

             
            Deer
             
            Why do deer shed their antlers?
          Deer shed their antlers annually as a prelude to the regeneration, or re-growth, of new ones.

          The entire shedding process takes a mere two to three weeks to complete, and the re-growth phase takes place over the summer. The docile male deer that, with the exception of the male and the female reindeer, solely sports antlers, sheds them between January and April, after the autumn mating season draws to a close. He can do without antlers at this time, because his need for them in prior months, to attract and to impress females for his harem of mates, and to fight with his competitors for the females' affections, no longer exists.

          The antlers themselves differ from the hollow horns of cattle, in that they comprise solid bone tissue with a honey combed structure. Pedicles, or knobby, skin-covered nubs protruding from the skull, support the deer's antlers, or points, which range in number from one shaft to eleven branches. The pedicles are a permanent fixture on the deer's forehead, and are the point from which the antlers annually break off.

          During the first year the pedicles appear on the young deer's forehead. The following year, the youngster sprouts straight, spike-like shafts, and in the third year, the first branch appears. In successive years, as the deer matures, his antlers lengthen and, in most species, he acquires additional branches. One can actually determine the age of the deer from the number of branches on his antlers, as their number increases with age.

          During the growth phase of the bony antlers, they are covered with a sensitive skin referred to as "velvet“, which is filled with blood vessels that feed the antlers the vitamins and the minerals necessary to build up the bone, and to promote normal antler growth. Antler growth spans two to four months, after which time the velvet is no longer needed, and a ring, which effectively serves as a shutoff valve, forms at the base of the antlers and cuts off the blood supply to the velvet. As a result, the velvet withers, dries up, and falls off, often assisted by the deer, which rubs his antlers against tree bark. The antler regeneration is complete, and the shedding cycle will resume once mating season in the fall concludes.

           

          note:

          prelude: 前奏

           

           

           

          docile: 溫順的


          sport
          : 炫耀,賣弄
          mating: 交配
          draw to a close: 漸近結(jié)束
          harem: 一群雌動物

           


          pedicle: 肉莖
          knobby: 多節(jié)的
          nub: 小塊

           

           

           

           

           

           


          velvet: 天鵝絨

           
           
           




          主站蜘蛛池模板: 日本激情久久精品人妻热| 国产精品一精品二精品三| 狠狠亚洲色一日本高清色| 中文字幕精品亚洲二区| 亚洲黄色一级片在线观看| 69久久国产露脸精品国产 | 人妻少妇精品中文字幕| 男人天堂亚洲天堂女人天堂| 亚洲亚洲中文字幕无线码| 国产suv精品一区二区四| 亚洲精品无码成人A片九色播放| 精品亚洲无人区一区二区| 欧美人与动牲交A免费观看| 色哟哟www网站入口成人学校| 亚洲欧美日韩尤物AⅤ一区| 国产AV一区二区精品久久凹凸 | 国产无遮挡裸体免费久久| 亚洲区1区3区4区中文字幕码| 2019香蕉在线观看直播视频| 性欧美VIDEOFREE高清大喷水| 亚洲色欲色欲www成人网| 亚洲自拍偷拍福利小视频| 女性裸体啪啪拍无遮挡的网站| 色偷偷成人综合亚洲精品| 久久精品蜜芽亚洲国产av| 亚洲首页一区任你躁xxxxx| 国产宅男宅女精品A片在线观看| 免费可以在线看a∨网站| 亚洲国产成人精品av区按摩| 粗大猛烈进出高潮视频| 国产国语一级毛片在线视频| 日本一高清二区视频久二区| 亚洲人成无码网站18禁| 精品久久人人做爽综合| 久久一二三四区中文字幕| 最近中文字幕日韩有码| 最近的2019中文字幕视频| 久久一亚色院精品全部免费| 亚洲国产亚洲综合在线尤物| 国产毛片子一区二区三区| 欧洲性开放老太大|