So great to see the increasing installment of access climbing tunnels (overhead tunnels a lot of the time) between exhibits for arboreal mammals (and sometimes others like Sumatran Tigers at Auckland Zoo). Is there any published info found online yet about when the first zoos in the world started to build them? (so far have found first use of o-lines for Orangutans being Nat' Zoo in Washington D.C but haven't found info yet on tunnels like these for Red Pandas, 'Lesser' Primates, Big Cats etc.
@steveroberts The Smithsonian National Zoo’s o-line opened in the 1990’s and is regarded pioneering. Other zoos have had simpler versions for decades such as bridges or ropes connecting islands for smaller primates. A few US zoos have overhead tunnels for big cats, but I agree it seems a more recent innovation. Adelaide Zoo have overhead tunnels for their tamarins too.
