. ▁ ▁At ▁times ▁in ▁North ▁America , ▁the ▁bands ▁have ▁just ▁a ▁unique ▁number ▁( without ▁an ▁address ) ▁that ▁is ▁recorded ▁along ▁with ▁other ▁ident ifying ▁information ▁on ▁the ▁bird . ▁If ▁the ▁bird ▁is ▁re capt ured ▁the ▁number ▁on ▁the ▁band ▁is ▁recorded ▁( al ong ▁with ▁other ▁ident ifying ▁characteristics ) ▁as ▁a ▁ret rap . ▁ ▁All ▁band ▁numbers ▁and ▁information ▁on ▁the ▁individual ▁birds ▁are ▁then ▁entered ▁into ▁a ▁database ▁and ▁the ▁information ▁often ▁shared ▁throughout ▁North ▁American ▁band ing ▁operations . ▁ ▁This ▁way ▁information ▁on ▁retra pped ▁birds ▁is ▁more ▁readily ▁available ▁and ▁easy ▁to ▁access . ▁ ▁Equ ip ment ▁used ▁ ▁Introduction ▁▁ ▁When ▁dec iding ▁on ▁bird ▁band ing ▁equipment ▁one ▁must ▁decide ▁what ▁species ▁of ▁bird ▁they ' d ▁like ▁to ▁focus ▁on . ▁Many ▁of ▁the ▁supplies ▁used ▁during ▁an ▁operation ▁are ▁determined ▁by ▁how ▁big ▁a ▁bird ▁is . ▁ ▁The ▁essential ▁equipment ▁includes ▁a ▁bird ▁identification ▁guide , ▁mist ▁n ets ▁or ▁other ▁tra pping ▁devices , ▁and ▁band ing ▁p liers . ▁A ▁leg ▁gauge , ▁wing ▁r uler , ▁and ▁a ▁digital ▁scale ▁are ▁also ▁useful ▁tools ▁for ▁data ▁collection . ▁Depending ▁on ▁the ▁country , ▁various ▁perm its ▁are ▁required ▁to ▁purchase ▁supplies ▁and ▁to ▁be ▁allowed ▁to ▁place ▁bands ▁on ▁the ▁birds ▁ ▁M ist ▁net ▁▁ ▁M ist ▁net ▁come ▁in ▁a ▁variety ▁of ▁sizes ▁and ▁lengths ▁according ▁to ▁the ▁bird ' s ▁size . ▁All ▁n ets ▁are ▁made ▁from ▁a