Tuesday, December 28, 2010

Back to Costa Rica and the Blue Jean Frog

This is the Strawberry Poison Dart Frog  (Dendrobates pumilio or Oophaga pumilio). 

It is tiny; less than an inch in length  (0.5 to 0.9")   There are many colour variations, ranging from solid red, to spotted to red body with blue legs - the variation found in Costa Rica at La Selva and also at Tortuguero on the East Coast.  This little tropical frog likes very humid, rainy places.   The locals call it "the red frog wearing blue jeans.

I came across this little one at La Selva.

The reproductive behaviours of rainforest frogs are unique and adapted to make use of the fresh water supply in the forest while avoiding tadpole development in ponds where they are prey for fish.

The following is taken straight from Field Guide to the Wildlife of Costa Rica by Carrol L. Henderson - which is a book everyone who visits Costa Rica should get.

Page 102 of my copy:

" The reproductive behavior of this frog is one of the most incredible stories in the rainforest.  Males establish territories on logs and stumps at a spacing of about ten feet.  Their mating call is a cricketlike buzz that pulses at a rate of four to five buzzes per second, deterring males while attracting females. If another male approaches, the two males rise up and grapple with each other like little sumo wrestlers.  When a female approaches, the male leads her to a nesting site in the ground litter, where he deposits sperm on a leaf and she deposits two to five eggs on it.  He guards the eggs and keeps them moist for about seven days until they hatch.

When the eggs hatch, the female instinctively returns, and the tadpoles climb onto her back.  They cling to her by using their mouths as suckers.  She climbs trees and backs into the water tanks of bromeliads or water-filled plant cavities.  The tadpoles slide into the water, and the female returns for the other tadpoles until she has placed all young ones.  She visits each tadpole every one to nine days for the fifty days it takes to develop.  When the tadpole senses its approaching mother, it vibrates its tail.  then she backs into the water and lays an unfertilized egg for the tadpole to eat!  She provides seven to eleven eggs for each tadpole during its development."

And that, I think, is pretty damn cool.

By the way, the restaurant Rana Roja from the last CR post... Rana = frog; roja = red. 

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