This post is in response to the question by Adrianna relating to frogs that use semaphore to comunicate. Many different species of frog are known to communicate in this way and I have witnessed this amazing phenomenon personally. Several species from Australia use this form of communication and several species from South America, including the Brazilian Torrent Frog, Hylodes asper. Some of the most well-known frogs for showing this adaptation belong a group of Asian torrent frogs from the genus Staurios. Staurios natator, for example, is a frog that inhabits the banks of rocky, fast flowing streams in primary forests and uses it back feet to foot-flag. To the right is picture of a male I photographed a couple of years ago whilst hiking down a stream in Northern Thailand.
To read a paper on the Brazilian Torrent Frog, Hylodes asper see:
and to watch video of a Central American frog species, Cruziohyla calcarifer, in action see: https://frogblogmanchester.com/2009/02/12/tree-frog-leg-waving/
Paper on Staurois guttatus: http://www3.interscience.wiley.com/journal/117987269/abstract?CRETRY=1&SRETRY=0
Paper on Staurois latopalmatus: http://pinnacle.allenpress.com/doi/abs/10.1655/08-037R.1?cookieSet=1&journalCode=herp