, ▁or ▁in ▁h ollow ▁trees . ▁ ▁See ▁also ▁▁ ▁Animal ▁navigation ▁ ▁Great ▁American ▁Inter change ▁ ▁Human ▁migration ▁ ▁M igration ▁( ec ology ) ▁ ▁References ▁ ▁Further ▁reading ▁ ▁In ▁general ▁▁ ▁A id ley , ▁D . J . ▁( 1 9 8 1 ) ▁Animal ▁migration . ▁Cambridge ▁University ▁Press . ▁ ▁Baker , ▁R . R . ▁( 1 9 7 8 ) ▁The ▁E volution ary ▁E col ogy ▁of ▁Animal ▁M igration . ▁Hol mes ▁& ▁Me ier ▁Publish ers . ▁ ▁D ing le , ▁H . ▁( 1 9 9 6 ) ▁M igration : ▁The ▁Bi ology ▁of ▁Life ▁on ▁the ▁Move . ▁Oxford ▁University ▁Press . ▁ ▁G auth re aux , ▁S . A . ▁( 1 9 8 0 ) ▁Animal ▁M igration , ▁Ori entation , ▁and ▁Navigation . ▁Academ ic ▁Press . ▁ ▁Mil ner - G ull and , ▁E . J ., ▁J . M . ▁F ry x ell , ▁and ▁A . R . E . ▁S inc la ir ▁( 2 0 1 1 ) ▁Animal ▁M igration : ▁A ▁Syn thesis . ▁Oxford ▁University ▁Press . ▁ ▁Rank in , ▁M . ▁( 1 9 8 5 ) ▁M igration : ▁Mechan isms ▁and ▁Ada pt ive ▁Sign ific ance : ▁Cont ribution s ▁in ▁Marine ▁Science . ▁Marine ▁Science ▁Institute . ▁ ▁R ied e , ▁K . ▁( 2 0 0 2 ) ▁Global ▁Register ▁of ▁Mig