The African bullfrog is notorious for its immense appetite and willingness to take on quite formidable prey, including venomous snakes, scorpions and centipedes (please see my article “An Appetite for Cobras” for further details). At breeding time, however, males display a quite unexpected side – that of devoted, even “tender” parents.
Taking on all Foes – Lions Included!
Approaching 9 pounds in weight and 10″ in length, male African bullfrogs are the heaviest, if not longest (that title goes to West Africa’s goliath frog, Conraua goliath) of all Anurans. Bony projections (odontoid structures) that function as teeth line their lower jaws and fights for breeding rights sometimes result in fatalities.
Upon successfully breeding, however, the male African bullfrog turns his pugnacious nature towards defending his numerous eggs and tadpoles, and he is fearless in that task. I have seen footage of one leaping at the faces of African lions that had shown interest in his precious charges (the lions were only about 2 years old, but still not animals to be taken lightly!). Startled by the frog’s complete lack of respect for their size, the lions quickly moved off!
An Anuran Engineer
Perhaps even more surprising, the attentive males will, using the hardened tubercles on their hind feet, dig channels in the earth to lead tadpoles from drying to water-filled pools (or, perhaps, to direct water into the natal pool).
Parent Turned Predator
Once the tadpoles transform into small frogs, all bets are off and the male ravenously consumes all that he can catch. Other African bullfrogs may constitute the majority of the diet of newly transformed animals as well…breeding pools dry quickly in most habitats, and the frogs must gorge themselves before retreating underground for a dormancy period that may approach 1 year in length.
There is, however, evidence of kin recognition in African bullfrogs…so relatives may be spared (or at least only eaten as a last resort!), as is the case for the tiger salamander, Ambystoma tigrinum. In that species, cannibalistic larvae have been shown to preferentially prey upon non-related animals.
I’ll cover the captive husbandry of this unique heavyweight in the future.
You can read more about this frog’s natural history at: