Still waiting for spring

I have not received any new reports of frogs calling in the Duluth area since Thursday, when the temperatures dropped and then a snowstorm blew in.  The birds have continued to sing, so I don't doubt that spring is truly here.  However, this weather has probably slowed the frogs down.  I don't expect any more frog activity until it warms up again, probably Thursday based on the current weather predictions.

Wood frogs (Rana sylvatica) are the first to start calling around Duluth.  The wood frog call is usually described as 'quark-quark-quark' or duck-like. Wood frogs are easily recognizable by a dark mask and white lip line.  In overall color they range from light to dark brown and sometimes are pink or reddish. 

wood frog

Within a few days, wood frogs are joined by Western Chorus Frogs (Pseudacris triseriata) and Spring Peepers (Psedacris crucifer). Both of these frogs are very small, reaching only 1 inch or 1.5 inches as adults, but make very LOUD calls. Chorus frogs sound like running your thumb over a comb and spring peepers make a really loud 'peep' over and over. Chorus frogs range in color from tan to brown to green and can be recognized by the strips on their back. Spring peepers are generally light tan with a slightly darker brown X on their back. 

chorus frog

spring peeper

To see when frogs begin to call across North America see the map at Journey North Spring 2011 - First Frogs

Next week I'll give some tips on identifying wood frog eggs (along with photos).

Spring is Finally Here!

That was the talk of the neighborhood this morning as we left for work in 50 degree temperatures.  Looks like tomorrow will be spring again, but the following few days may take us back to late winter.

It has only been 4 days since I visited the frozen wetlands, but I will head out again tomorrow to see if they have opened up yet.  If the vernal pools are open, we can expect the wood frogs to be calling and laying eggs in about a week!

In case you were wondering what these amazing northern frogs might be up to right now - they are probably in the process of thawing out.  Yes, wood frogs are the famous frozen frogs!  Most amphibians find more suitable habitat for winter hibernation, such as a sandy hole below frostline or the muddy bottom of a larger lake, but wood frogs spend the winter frozen in the leaf litter.

This NOVA segment is a great intro to frozen frogs

(link to higher quality video)

You can learn more at: Frozen Frog: Expert Q & A (Jon Costanzo)

Is it spring yet?

Spring comes slow to northern Minnesota - this year it seems exceptionally slow, perhaps due to the super early spring of 2010.  Although the robins and cardinals are singing in my yard, we will be waiting a few more weeks before the frogs start to call.

I visited some ponds located within city limits today - still frozen and snow covered (see below).

Quite a difference from this time last year, when the ponds were open and the wood frogs had already laid their eggs! On April 7, 2010 this same location looked something like this:

While we wait for the ponds and lakes to open up, all we can do is practice our amphibian ID skills.  The first frog to call and breed in this region is the wood frog (Rana sylvatica). I recommend the Online ID Guide from Northern Prairie Wildlife Research Center for great pictures and maps, and the Amphibians of Reptiles of Minnesota for detailed descriptions and calls.