Wednesday, January 2, 2013

Foamy reproduction!

After almost exactly 24 hours - the music fell silent at La Rochelle at 21.30pm yesterday, as our New Years Eve party finally subsided.

Those Russians are CRRRAAAYZEEE I tell you!

So - onto more mundane matters. Like frogs.

About a week ago I took photos down at the ponds of 2 foam frog nests. These are the distinctive breeding sites of the Grey tree frog - (otherwise known as the 'Foam nest frog') and the nests appear and disappear almost overnight.

The mother frog whips up a foam - rather like a meringue - into which her eggs are laid, and fertilised by the males. The nest always overhangs a pool of water - normally an ephemeral (short-lived) one, though in our case the moms made their nests above our ponds - which have water all year round.

These short-lived ponds - more often than not large puddles, are almost always as a result of rain - and so the frogs have a distinct breeding season.

The eggs hatch - and the tadpoles actually spend some time in the foam - growing to about 1cm, before they drop out of the nest and into the water body below. So.... tadpoles that live out of water - clever, hey? The foam protects the young and the eggs from the heat of the sun, as well as from predators, and the foam provides a constant incubation environment. The nest disintegrates fairly quickly once the tadpoles start dropping into the water below - and a heavy rain over this time washes it away very quickly.

I think the main protection is provided by simple concealment - though I must try and find out if the foam is toxic in any way.

So - here in all their glory, are the nests of the Grey tree frog. Visible from miles away, they are easy to spot. Our pond had 2 distinct nests - occasionally the nests will merge to make a large one. The standard nest is about the size of a small melon - and different males may well fertilize the eggs in one nest.

Sometime nature stuff is SO amazing!

No comments:

Post a Comment