by Berislav Horvatic » Sat Jan 07, 2012 6:12 pm
Does Pelophylax ridibundus count as well?
Jelić Dušan, Marchand Marc Antoine, Svoboda Petra: Description of an unusual
antipredator vocalization in Marsh Frog, Pelophylax ridibundus (Pallas, 1771),
2nd Mediterranean Congress of Herpetology, Marrakech, Morocco, 23 - 27 May 2011
I've heard it only once in vivo, from a frog being swallowed by a Natrix natrix.
But Dušan Jelić has also made some experiments - publication to follow.