A biologist named hugh dingle , striving to understand the essence , has identified five characteristics that apply , in varying degrees and combinations , to all migrations .
生物学家休丁格尔识别出符合不同程度和组合的所有迁徙的五种特征,力争了解其本质。
" Animal migrants do not respond to sensory inputs from resources that would readily elicit responses in other circumstances , " is the dry , careful way dingle describes it .