these quiet, unobtrusive calls. 这种轻声低语背后的意思

122. But the dholes could easily lose track of one another.
     但同时豺也很容易跟丢大部队
123. So they use their unique whistles.
     它们独特的口哨派上了用场
124. Only dholes can understand
     只有豺才能理解
125. these quiet, unobtrusive calls.
     这种轻声低语背后的意思
126. Now they take up their hunting positions...
     现在豺群各就各位
127. ...even though they can't see each other.
     尽管看不见彼此 也能默契合作
128. With the deer surrounded...
     花鹿被包围了

来自《行星地球 第三季 第五集 Planet Earth S03E05 森林》第 125 行