agile gibbon ([i]Hylobates agilis[/i]) on left and white-handed gibbon ([i]Hylobates lar[/i]) on right
compare the size of these two cages with the size of the aviaries just ten or twenty metres away
http://www.zoochat.com/1231/aviaries-146938/
October 2009
review here:
http://www.zoochat.com/238/medan-zoo-north-sumatra-112525/