Sclerophrys vittata

The mating calls have a simple structure. They consist of three to four very short pules separated by intervals. Calls have been recorded at water temperatures of 17 to 27 degrees Celsius. At 24 degrees water temperature the mean call duration measures 120 milliseconds, the intercall interval 300 milliseconds, the calls exhibit two frequency components at about 1100 and 2800 Hertz. There is a correlation between the water temperature and some call parameters. As the water temperature increases the duration of the calls decreases when the calls consisting of three or four pulses are considered separately. The intervals between the calls and between the pulses also decrease, whereas the pulse rate increases. The number of pulses per call and the duration of the pulses do not change.[4]

Calling of the males begins in the first half of February and lasts until October. It reaches a climax in spring and early summer. During this time calling begins shortly after sunset and lasts until 1 to 2 a.m. Later in summer calling ends earlier, around 10 to 11 p.m. and ends in September and October even earlier.[4]

Calling males gather in small shallow ponds, irrigation canals and ditches, rice and corn fields. They form choruses consisting of about 20 males. The calling males maintain a minimum distance of about 0.7 meters. At decreasing calling activity during the year, males continue to form choruses, but the number of choruses decreases. Males call while sitting in the water, the body is erected, the hind limbs and the posterior part of the body are immersed in the water. The males have a single subgular vocal sac. When fully inflated, it is very large in relation to the body length. Pair formation is high in spring and early summer, later on it decreases, but pairs are observed until October.[4]