The Giant African Bullfrog is a species of frog in the family Pyxicephalidae. It is also known as the pixie frog due to its scientific name. It is found in Southern and Central Africa.
It is among the largest frogs, with males weighing up to 1.4 kg. Females are half the size of males, which is unusual since in most amphibian species females are larger than males. Males can reach 24.5 cm in snout–to–vent length, while females are much smaller.
Feeding and Habits
This bullfrog is an insatiable carnivore, eating insects, small rodents, reptiles, small birds, and other amphibians. It is also a cannibalistic species, and it is well known that the male of the species occasionally eats the tadpoles he guards when population density is high and food availability is low.
Bullfrogs in Gauteng usually bury themselves below the soil surface outside of breeding season. This burrow is often located within a 200 meter radius of the breeding site, and can vary in depth from 0.5cm to 20cm below the surface, depending on how sandy the soil is. Both male and female adult bullfrogs are highly faithful to their burrows within and even between summers.
Breeding starts after heavy rain (initiated by about 50 mm of rain over the course of two days), and Giant Bullfrog males have two breeding strategies, depending on their age. Young males congregate in a small area, perhaps only 1 or 2 m2 of shallow water, while the larger males occupy the center of these breeding arenas and attempt to chase off other males. Often, they fight, causing injury or even killing one another in their attempts to prevent others from breeding. When a female approaches the group of males, there is only one strategy in her mind … “avoid the young one’s and find the strong ones”. She achieves this by swimming along the surface of the water until she is within a few meters of the group, and then dives to avoid the smaller males and surfaces in the defended area of a larger male. This helps to ensure that the smart ladies mate with the dominant males.
Breeding takes place in shallow, temporary water bodies, such as pools, pans, and ditches, but eggs are laid in the shallow edges of the pond, while fertilization takes place above water.
The female lays about 3,000 to 4,000 eggs at a time and the tadpoles hatch within a couple of days and immediately start feeding on vegetation, small fish, invertebrates, and even each other.
After mating, the biggest male bullfrogs will remain at the breeding site to look after their offspring and will physically attack animals or people that threaten their them. They will also use their back legs to dig channels around the edges of the breeding site to improve water availability, depth and temperature for growth and survival of their eggs or tadpoles. The male continues to guard the tadpoles until they are old enough to fend for themselves.
Photograph by Anthony Stewien