Spawning behaviour and male mating tactics of a foam-nesting treefrog, Rhacophorus schlegelii

Spawning behaviour and male mating tactics of a foam-nesting treefrog, Rhacophorus schlegelii, were observed in the field and laboratory. This frog makes a foam nest for its eggs under the soil on the shores of ponds. Radio-tracking in the field showed that spawning with one female and more than one male took place in four of nine natural nests. Laboratory observations showed that unpaired males sneaked into a nest after a pair had constructed a spherical hole for oviposition in the soil. Sneaking behaviour by unpaired males was observed in 10 out of 12 instances of spawning in the laboratory. Paired males and sneaking males did not differ in mean snout-vent length in either the laboratory or the field. The majority of sneaking males were calling before they sneaked into the nest. Sequential observations using the same males revealed that males adopted both calling and sneaking tactics and switched between them frequently.