Welcome to the Marine Mammal and wildlife Research and Community Development Expedition blog where you can keep up to date with all the happenings and information from Kenya

Sunday, May 3, 2009

The Frog Blog Part 2 - Saturday Night Frog Fever

Matt wrote earlier in the week about an exciting frog find in the forest and as Saturday night came round his rainy season wish came true. At our forest base and office in Shimoni we were decidedly ‘off-duty’, kicking back and watching a film...

Just before hitting the sack, I noticed a little visitor perched on the bars of the kitchen window and so our mini research team kicked in to action. Recognising the small amphibian from an individual we had caught a few years before, it didn’t take long to identify. We are fairly confident we have our second Tinker Reed Frog, or Hyperolius tuberilinguis.

This beautiful yellow-green reed frog reveals striking red-orange backs of the thighs when jumping. It has been suggested that this trait may serve to startle predators as it makes its escape, but the colour is the result of a concentrated supply of blood vessels under a thinner layer of skin, enabling an area of rapid water uptake, important for amphibians living in tropical East Africa! The body length of the frog suggested it may be a male, males often being smaller than females in the amphibian world, however the lack of a bright yellow throat indicates the reverse. If it was a female, the she may well have been out looking for a pool of water above which she can lay up to 400 eggs above the surface, attached to vegetation.

With the Hyperolius being a somewhat tricky genus within which to determine species, we’re pleased to have had an easy job with this one and look forward to seeing what else the rains will bring us. Would be nice if they gave us Saturday nights off though...




Sara Mayer said...

Yay Frogger! I think the cottage kitchen should be deemed it's OWN biodiversity hotspot! Cool to learn that fact about throat color determining gender - is that true of this species only or does it apply to other amphibians?

GVI Kenya said...

Hi Sara, it's true we seem to get as much wildlife passing by the cottage as we do in the forest! For this species in particular, males exhibit a bright yellow throat whils the female has a white / cream throat. There are other species where colouration of areas such as the throat are indicative of sex. Males call to attract mates, enlarging their throat sac to make the calls, so a birght colour could act as a strong sexual signal. However for many other species, especially those that are cryptically coloured rather than brightly coloured such as this one, anatomical features can be more telling - in some Arthroleptis for example males are characterised by an elongated middle digit... maybe to give them a better grip during mating! Haha, tune in for more frog facts throughout the rains...!