▁ ▁Lim itations ▁▁ ▁C ertain ▁bird ▁species ▁are ▁for ▁various ▁reasons ▁un su itable ▁for ▁ring ing . ▁In ▁some ▁countries , ▁such ▁as ▁Australia , ▁there ▁exist ▁laws ▁prohib iting ▁band ing ▁of ▁such ▁species . ▁ ▁Many ▁very ▁large ▁birds , ▁such ▁as ▁rat ites , ▁fl aming os ▁and ▁the ▁largest ▁sw ans , ▁are ▁extremely ▁difficult ▁to ▁band ▁because ▁the ▁cost ▁of ▁making ▁a ▁band ▁which ▁is ▁capable ▁of ▁secure ly ▁fitting ▁their ▁strong , ▁heavy ▁legs ▁is ▁prohib itive . ▁At ▁the ▁other ▁extreme , ▁the ▁smaller ▁species ▁of ▁river ▁and ▁tree ▁king fish ers , ▁tod ies ▁and ▁certain ▁l ories , ▁have ▁such ▁narrow ▁tar si i ▁that ▁a ▁band ▁can ▁be ▁secure ly ▁placed ▁around ▁the ▁birds ▁foot ▁without ▁impos ing ▁danger ▁to ▁blood ▁circul ation . ▁With ▁some ▁game bird s , ▁such ▁as ▁the ▁Indian ▁pe af ow l , ▁sp urs ▁on ▁the ▁legs ▁inter f ere ▁with ▁the ▁bands , ▁which ▁thus ▁can ▁cause ▁injury ▁to ▁the ▁birds . ▁ ▁Many ▁species ▁of ▁co ck ato o ▁– ▁which ▁even ▁if ▁able ▁to ▁be ▁band ed ▁require ▁special ▁bands ▁to ▁fit ▁the ▁unique ▁shape ▁of ▁their ▁legs ▁– ▁will ▁cr ush ▁bands ▁with ▁their ▁powerful ▁b ills ▁and ▁cla ws . ▁The ▁ability ▁to ▁overcome ▁this ▁problem ▁var ies ▁between ▁species , ▁and ▁with ▁some ▁such ▁as ▁the ▁Gang - gang ▁co ck ato o , ▁it ▁is ▁known ▁to ▁be ▁too ▁dangerous ▁to ▁attempt ▁band ing . ▁New ▁World