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Frog Friday: Cope’s Gray Treefrog

Two weeks ago, we introduced the Gray Treefrog. Today, we present its doppelganger, the Cope’s Gray Treefrog. The Cope’s Gray Treefrog (Hyla chrysoscelis) is physically identical to the gray treefrog (Hyla versicolor). So, how does one know which is which? Cope’s Gray can be differentiated in the field by two methods:

  1. location (in most cases), and
  2. their advertisement call.

Cope’s Gray Treefrog is limited in its range, occurring in the coastal plain and the most southwestern mountains of Virginia, where as the Gray Treetrog occurs primarily through the piedmont and the northwestern mountains (see range maps below). The call is a similar to the Gray Treefrog but is shorter and harsher with a higher frequency, often more than 45 trills per second. The melodic trill lasts for one to three seconds and ends abruptly. Listen to both calls bellow and see if you can differentiate the two species.

Call of Cope’s Gray Treefrog:

Call of Gray Treefrog

The two gray treefrog species can also be differentiated genetically.  Though similar in appearance, the species cannot interbreed.

Copes-Gray-Treefrog-01

Coloration in Cope’s Gray Treefrogs varies widely depending on their environment. The frog’s scientific name is Hyla chrysoscelis latin for “belonging to the woods” (Hyla) and golden spots (chrysoscelis) referring to the yellow or orange coloration with spots on the inside of their hind legs. Typically they have a dark “star-shaped” pattern on their back with many small warts. Background coloration varies from gray to tan or even light green. It has a white spot beneath the eye, and bright yellow or orange on the on concealed surface of the thighs.

As the name implies, they are typically found among the foliage of small trees and shrubs located along or actually standing in streams, rivers or ponds. They are thought to forage at a lower height in the trees than Gray Treefrogs. Seldom found on the ground except during the breeding season, they spend most of their time foraging on insects primarily butterfly, moth, and/or beetle larvae.

Copes-Gray-Treefrog-TadpoleBreeding season typically occurs from April – August in small, shallow water habitats like roadside ditches, beaver ponds, and woodland depressions. Eggs hatch in 4-5 days and tadpoles metamorphose in 45-60 days.

This article is presented as part of our year-long Virginia is for Frogs campaign. Please visit the campaign webpage to learn more about Virginia’s 27 frog species and ways that you can become involved in their conservation. Are you an educator? Check out the Virginia is for Frogs Teacher’s Corner for frog-related lesson plans and activities.

Photos by John White.

  • August 28, 2015