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Saturday, March 17, 2012

Pacific Chorus Frogs

Rain for most of the past week created favorable conditions for amphibians.  The most common frog on Bodega Head is the Pacific Chorus Frog (or Pacific Treefrog), Pseudacris regilla.  You can encounter them just about anywhere, but for breeding they prefer shallow pools.

Here are a few photos from 17 March 2012.  

A male-female pair in amplexus (mating embrace).  The smaller male is holding the larger female from above.  Fertilization is external.  The female will attach eggs to a submerged object (see below), and the male will release sperm to fertilize them. 

View from above.

View from front.

Eggs are laid in small clusters attached to grass or twigs.  They are brown above and cream colored below and are embedded in a gelatinous matrix.

Note the rounded toe pads on the hind foot, a distinctive character of treefrogs.  For this species, the black line running from the snout past the eye and to the shoulder is a helpful field mark.

You can listen to Pacific Chorus Frog calls here.

1 comment:

Anonymous said...

great photos !!! c