Thursday, 16 January 2014

Wildlife and Nature Pictures - Natures Female Swingers (Polyandry)

Wildlife Species-Grey Foam Nest-Tree Frogs  

In the wonderful world of nature many wildlife species do not stick to the general rules of 'one' mate during a breeding season. ie.. one male-one female or visa -versa..  In our human world it is broadly categorised as 'Polygamy' (having more than one spouse)  In natures animal kingdom, species that mate with more than one member of the opposite sex  during a breeding season is  termed as  'Polygyny' (A male mates with more than one female during a breeding season) or 'Polyandry' (A female mates with more than one male during a breeding season).

It is the latter 'Polyandry' on a grand scale that this female species of frog known as the Grey Foam Nest-Tree Frog (Chiromantis xerampelina) participates in. Currently all over Limpopo province where I live as well as in the rest of South Africa, I see dam's (pool's, lakes, pond's or general standing water) with the intriguing nests of this industrious and clever medium sized (+/- 100mm) frog .

The female Grey Foam Nest-Tree Frog  starts by climbing up the vegetation which will be overhanging water, sometimes this maybe many meters up from the waters surface. She then starts to deposit her eggs (many hundreds) on a branch or over a hanging protrusion over the water. At the same time she also secretes a 'sticky liquid' which is manipulated and kicked and worked up by her back legs to form a large 'foam nest', some I have seen are as big as footballs! At this point, it is where the many attendant males, as many as 12 or so ('simultaneous polyandry') fertilise the eggs with their sperm. 

The 'foam nest' helps prevent dessication of the eggs (drying out) and also minimise predation of her eggs and tadpoles, as frogs and toads that would normally lay their eggs in the water are susceptible to this problem. Once the eggs have hatched in the nest  and after 3-5 days the little tadpoles wriggle and drop out the 'foam nest' into the water below to continue their feeding and metamorphosis life cycle after being given the best possible start in life.

Wildlife and nature are full of interesting facts, one of these facts concerning the Grey Foam Nest-Tree Frog is also quite interesting.  Like most frogs the Grey Foam Nest-Tree Frog is susceptible to 'drying out' and the reason why most frogs are nocturnal and active during the cooler parts of the day. However,  mother nature provides these frogs with the ability to produce a 'mucus' type skin all over their bodies which combined with the with-drawing of their limbs 'close' to their bodies, it helps prevent the 'drying out' happening and thus retain their  body moisture.


Grey Foam Nest Frog and Foam Nest- Nature and Polyandry
Grey Foam Nest Tree Frog (Chiromantis xerampelina) - (limbs withdrawn to help loss of body moisture)
and a 'Foam Nest'