日韩精品久久一区二区三区_亚洲色图p_亚洲综合在线最大成人_国产中出在线观看_日韩免费_亚洲综合在线一区

您現在的位置: > 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: 漸近結束
harem: 一群雌動物

 


pedicle: 肉莖
knobby: 多節的
nub: 小塊

 

 

 

 

 

 


velvet: 天鵝絨

 
 
 




主站蜘蛛池模板: 成人性视频免费网站 | 天天爽夜夜爽 | 免费观看一级毛片 | 亚洲日本中文字幕 | 国产精品亚洲综合 | 四虎在线免费观看视频 | 成人在线视频精品 | 中国在线播放精品区 | 欧美日韩在线电影 | 无遮挡一级毛片私人影院 | 青草视频污 | 欧美国产日本高清不卡 | 91精品国产色综合久久 | 波多野结衣一区二区三区四区 | 九九视频精品全部免费播放 | 久草免费在线 | 色天天影视 | 国产精品免费播放 | 91久久精品一区二区三区 | 亚洲欧美v国产一区二区 | 午夜宫电影 | 四虎影视在线看免费完整版 | 日韩精品www | 啊啊啊网站 | 国产亚洲综合一区二区在线 | 亚洲精品美女久久777777 | 波多野吉衣一区二区三区四区 | 两性视频在线 | 国产男女交性视频播放 | 国产午夜精品久久久久久久蜜臀 | 污视频网页 | 日本韩国一区二区三区 | 精品极品三级久久久久 | 中文字幕一区在线观看视频 | 美女网站黄在线观看 | a4yy午夜| 欧美一区二三区 | 综合网女女网 | 国产精品国产a级 | 国产色婷婷精品综合在线观看 | 欧美特黄一级视频 |