Aspects of the breeding biology of the Omei mustache toad (Leptobrachium boringii): polygamy and paternal care

The Omei mustache toad, Leptobrachium boringii, has a male biased sexual size dimorphism, which may be associated with either male-male combat behaviour or parental care. The breeding biology of this species was studied during the 2004, 2006, and 2007 breeding seasons in a population at Mount Omei in western China. The size and sex ratio of this breeding population fluctuated over the years. Males constructed nests under large rocks in mountain streams and a single “resident” male typically occupied one nest and remained in the same nest for the entire study periods with rare exceptions. Males with egg masses in their nests stayed in their nests for many days after oviposition, with few or no additional matings during this period, suggesting that males were possibly providing paternal care rather than waiting for more mating opportunities. Furthermore, males lost a significant amount (7.3%) of their body mass during the breeding season. In 2006 and 2007, we also found a positive correlation between the body size of the resident male and the number of egg masses in his nest. However, parentage analysis using microsatellite DNA loci indicated that resident males were not necessarily the fathers of all eggs in their nests. Both polygyny and polyandry occur in this species. Overall, evidence suggests that Omei mustache toads provide paternal care and larger males have higher mating success.