A cougar cub being weighed at Salzburg Zoo, Austria. (File Photos: IC]

A young wild owl being measured, weighed and ringed, in the zoo in Arnhem, The Netherlands.

Elephant calf 'Uli' refusing to stand on a scale at the Wuppertal zoo in Wuppertal, Germany.

A Red-Ruffed Lemur called Cid being weighed at the London Zoo.

An eagle owl being measured, at the London Zoo.

A Malayan tiger cub being weighed at the Zoo in Prague, Czech Republic.