Thursday, July 6, 2017

Froglets


We've had to watch our step in the garden during this week's wet weather, because the tadpoles in the pond have been metamorphosing into tiny froglets that are about the size of my thumbnail.  They would be so easy to tread on. Still, it's a great excuse for not mowing the lawn, as they seem to spend a lot of time in the grass.















A tiny froglet like this has a lot of growing to do before it reaches reproductive age. When they are this size they are prey for birds and perhaps even larger ground beetles and centipedes





































They need to adapt quickly to their change in buoyancy during the last days before they leave the pond. Tadpoles absorb oxygen dissolved in water via external gills and over their skin surface and if they stop swimming they sink, but once they become froglets their internal lungs take over and the air inside their bodies makes them float to the surface to gulp more air. 

This one seems to be just chilling, floating with only its nostrils above the water. 





































At this stage the froglets must be able to climb out of the water but ...
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...... when they first metamorphose they are light enough to sit on the water surface.

There is often one important hazard that froglets face when they try to leave ponds that are surrounded by paving on warm, sunny days. Dry paving stones can become very hot underfoot and I have seen froglets perish in their attempts to cross them, so an area of grass around a pond that reaches down to the water surface offers a much safer escape route.

2 comments:

  1. I love these photos! Thanks for posting.

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    1. Thanks! So glad you enjoyed them. Watching this magical transition is something I never get tired of. My two year-old grandson is coming to see them tomorrow. He's only just learned to say 'tadpole', now I need to teach him 'frog'!

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