SOUTHERN BELL FROG
(Litoria raniformis)
Synonymy: Green frog
The
southern bell frog which grows to a length of 105mm was introduced
from Australia in 1870. It is one of three common Australian imports
seen around New Zealand,
the other two
|
species being the golden bell frog and the whistling tree
frog.
New
Zealand has three species of native frog but these are very
rare and secretive so any frog you may come across will
almost definitely be introduced. |
 |
New
Zealand’s native frogs (Leoipelma spp.) are unusual in
that their eggs are laid in moist muddy areas under stones and
logs. The tadpole stage takes place within the egg and a young
froglet hatches, unlike other species where there is a freeswimming
tadpole.
FROG
FACTS
When frogs are inactive they breathe almost exclusively through
their skin and mouth lining, however they need more oxygen when
they are hunting etc so they need to ‘gulp’ air.
This forces air down into their lungs (compared to humans where
our muscular diaphragm results in sucking air into the lungs).
Frogs shed their skin (and then eat it!) to get rid of unwanted
external parasites. Replacing it with new moist skin also maintains
the ease with which they breathe.
Frogs do not have eyelids but instead have a see-through nictitating
membrane that moistens, cleans and protects the eye. The eyes
protrude upwards so the rest of the body can remain submerged
when looking for potential predators such as the heron. When
feeding on a particularly large animal, the eyes can actually
be retracted into the head, applying pressure on the back of
the throat. This helps force the food down into the stomach!
Frogs that live on land will generally have straight, narrow
toes and those that live mostly in water will have webbed feet.
The green and whistling frogs are both tree frogs, and as such
have suction pads at the end of their toes to assist with climbing.
Females can make noises (very rarely), but not the croak associated
with frogs. It is the male that calls frequently and loudly.
New Zealand’s native frogs cannot vocalise loudly at all
and have no eardrums with which to pick up on such communication.
Frogs are carnivores and will only eat live food. New Zealand’s
frogs (native and introduced) seize their prey by ‘lining
it up’ and then pouncing. They do not use their tongues
to capture prey like many other frogs.
