Wednesday, March 23, 2011

Mountain Chorus Frogs Emerge

The first mountain chorus frogs (Pseudacris brachyphona) of the season were heard chorusing yesterday in a small ephemeral pool in Wayne township.  Mountian chorus frogs are cousins to the more widely distributed spring peeper (Pseudacris crucifer) and western chorus frog (Pseudacris triseriata) in Ohio and represent a branch of the treefrog community.  Generally speaking their range is restricted to upland slopes of the unglaciated hill country of southeastern Ohio.  Local populations seem to prefer shallow upland pools in ditches, tire ruts and depressions that are not influenced by heavy flows of spring water and are south facing.  Their vocalizations are often compared to the sound made by running a finger down the edge of a fine-toothed comb and have considerable carrying power under the right conditions.  Mountain chorus frogs often use the same breeding pools as wood frogs and american toads.  Thanks to Ted for the opportunity to observe a new population.

Great habitat for mountain chrous frogs congregations in spring.
Runoff has been dammed by a waterbar placed on this hillside
to control erosion.  Shallow pools are preferred as long as they
don't dry out too quickly later in the spring.  Wood frog egg masses
were also observed at this site. 

An adult male mountain chorus frog.  Note the reverse
parenthesis on the back and dark triangle between the eyes.
Their small size cryptic color pattern make them nearly
impossible to locate in pools, even when chorusing.

Side profile of the same male.  Note the light line on the upper
lip.  Believe it or not this guy has a booming voice for his size. 

Can you find the chorus frog against this background?
Most predators can't either - a testament to the
frog's cryptic color pattern and small size.

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