These heavyweight amphibians are African bullfrogs
and they breed explosively
when the heavy summer rains create temporary pools.
Each male competes for a succession of females and fertilizes their eggs.
He would accumulate several batches of spawn, amounting to thousands of eggs.
When the exhausted females leave,
it's a powerful incentive for him to stay.
There's another good reason to:
Tadpoles need help to survive the tropical sun
and its shrinking effect on their shallow pools.
The father takes action
and shepherds his shoal like a sheepdog herding a flock.
If the water gets too hot, he herds his tadpoles
into cooler, deeper water with a better supply of oxygen.
A hefty male also assumes the role of guard dog.
The tadpoles are once again heading for disaster.
Their nursery pools are temporary
and prone to dry up in the heat of the withering sun.
This devoted parent is not about to give up yet.
A lower land dweller himself,
he senses the need to keep his offspring aquatic.
Using his strong back legs and pointed snout,
the male digs a channel to a neighboring puddle
to save his family.
This excavation work will flood his own nursery
or act as an escape route.
In such circumstances, a dutiful father is key to survival.