Male-male aggression trial (VIDEO) Gettysburg College This video is under embargo. Please login to access this video. Caption A male red-eyed treefrog responds to sound and vibrations of a rival male's call by producing aggressive vibrational signals. Credit Dr. Michael Caldwell Usage Restrictions N/A License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.