Androgen levels in a Bornean voiceless frog, Rana blythi

Male Rana blythi and males of three other species of voiceless frogs from Bornean rain forests lack the suite of secondary sex characteristics typical of most anurans: nuptial pads, vocal sacs, enlarged forearm flexors, and male advertisement calls. At the same time, basal species in the voiceless frog lineage exhibit an extreme type of male […]