Central Coast Stubfoot Toad

To attract females and to defend their territories, males of A. franciscus use advertisement calls, not visual displays as typical for Atelopus. This is somewhat unexpected, given their environment is noisy and males must acoustically compete with males of several other frog species (e.g., Allobates femoralis and Otophryne pyburni). Moreover, this species lacks an external vocal sac, so can only produce low-intensity calls that propagate short distances—less than eight metres (26 ft). It also lacks external tympana and could be considered anatomically deaf. Nevertheless, it has a well-developed inner ear and has been shown to respond acoustically to the calls of conspecifics in the field. Male territories are closely spaced, only 2–4 metres (6 ft 7 in – 13 ft 1 in) apart on average, and despite the handicaps discussed above, acoustic communication appears sufficiently efficient at these short distances. Eggs are laid in the water. The tadpoles adhere to rocks.

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