▁sources , ▁particularly ▁the ▁earlier ▁natural ▁histor ies ▁or ▁orn ith ologies ▁by ▁Ul isse ▁Ald rov and i , ▁Pietro ▁Ol ina , ▁Georg ▁Marc gra ve ▁and ▁Wille m ▁P iso . ▁Where ▁feas ible , ▁Will ugh by ▁and ▁Ray ▁compared ▁the ▁available ▁illustr ations ▁with ▁life ▁or ▁spec im ens , ▁or , ▁if ▁that ▁were ▁not ▁possible , ▁against ▁each ▁other , ▁to ▁select ▁the ▁most ▁accurate ▁version ▁for ▁publication . ▁In ▁addition ▁to ▁these ▁authors , ▁sources ▁used ▁for ▁the ▁text ▁included ▁works ▁by ▁Carol us ▁Cl us ius , ▁Ad ria en ▁Col la ert , ▁Ger v ase ▁Mark ham , ▁Juan ▁E use bio ▁N ier emberg ▁and ▁Ole ▁W orm . ▁Ol ina ' s ▁U cel li era , ▁at ▁least , ▁seems ▁to ▁have ▁been ▁revis ited ▁between ▁the ▁Latin ▁and ▁English ▁ed itions ▁of ▁the ▁Or n ith ology , ▁since ▁the ▁later ▁version ▁contains ▁a ▁description ▁of ▁territorial ▁behaviour ▁by ▁the ▁night ing ale ▁absent ▁from ▁the ▁earlier ▁work . ▁ ▁Leg acy ▁ ▁Much ▁of ▁Will ugh by ' s ▁written ▁work ▁has ▁been ▁lost , ▁along ▁with ▁his ▁scientific ▁equipment ▁and ▁most ▁of ▁his ▁collections ▁of ▁items ▁of ▁natural ▁history ▁interest ; ▁what ▁remains ▁is ▁largely ▁owned ▁by ▁the ▁family ▁and ▁hous ed ▁in ▁the ▁University ▁of ▁Not ting ham ▁Middle ton ▁archive . ▁The ▁Or n ith ology ▁influenced ▁Ré am ur ▁in ▁organ ising ▁his ▁great ▁bird ▁collection , ▁and ▁Br isson ▁in ▁the ▁compilation