Photo by Corey Husic

Saturday, April 9, 2011

On Spring Peepers (Pseudacris crucifer):

From Tuscarora Township, Bradford County:  Peeping started Monday night (4/4), the frogs were silent Tuesday, and then were loud again on Wednesday (4/6).

From Beaumont, Wyoming County: a few Spring Peepers called for the first time on Wednesday night (4/6/11).

These reports illustrate how "signs of spring" gradually move north.  I received a report of Spring Peepers at Middle Creek on March 13th, but don’t know if that was a seasonal “first” or not.  In our area, the reports were varied (March 12th-18th in areas around our property in Kunkletown, in the SE corner of Monroe County, just north of the Kittatinny Ridge).  The peeping at our pond started quite a bit later (April 3rd) than at these other areas very close to us.  Perhaps this represented a migration to our pond from surrounding areas for breeding.  But in the northern counties the first "peeping" was several weeks later most likely reflecting differences in temperatures between the areas.

I received an email today from someone who said that they had always been told that spring peepers have to "freeze up" or be silent three times before it gets warm.  Have others heard this piece of lore?  Is there any truth to it?  This is an important thing to pay attention to in the future.
The gardeners use phenological events in nature to guide planting.  Apparently, when you hear Spring Peepers, it is time to plant peas (  Where I live, that would be about right.

Eric Rensel, the Natural Resource Specialist to Park Region 1 (office at Parker Dam State Park in western Pennsylvania) has shared some phenological records from northern Clearfield County for us to compare with eastern PA.

Here are his records for first hearing spring peepers going back to 1995.

First Dates for Spring Peeper Calls in Clearfield County (Eric Wensel)
Some fun facts about Spring Peepers (see sources below):
§       Northern Spring Peepers spend the winter burrowed into soil or under logs and leaves. 
§       As a biochemist, I loved learning that they survive the freezing temperatures of winter by producing a sugar alcohol (glycerol) that serves as an anti-freeze preventing the formation of ice crystals in their cells!  They thaw and come out of hibernation when warm temperatures return in the spring.  Isn’t that awesome?!
§       The peeping in spring is from the males trying to attract a mate.  Anyone who lives in a heavily peeper-populated area knows how loud the males can be especially on warm nights.
§       There are different calls when males fight; a lower-pitched trilling whistle is made if one male moves in too close to the territory of another.  I wonder if anyone has witnessed frogs fighting.
§       The females reportedly choose their mate by the quality of the call.  (I can’t hear differences between the calls except for volume and the frequency of repetition.) Some reports say that the frogs that call the loudest and fasted are more likely to find a mate.
§       The females lay between 750 and 1300 eggs in small clusters attached to submerged vegetation.  Thus, the frogs must live near pools of water.  Breeding occurs between March and June (April is the main month).
§       Afterwards, they disperse to woodlands and swampy areas and live relatively solitary lives.
§       Tadpoles hatch in 4 to 15 days; metamorphosis occurs between 45 and 90 days after hatching.
§       They can climb but prefer to be on the grown or burrowed in the dirt.  I am convinced that they sense vibrations on the ground.  Whenever we quietly try to sneak up on them by our pond at night, they stop peeping.  When we walk away, they start up again.
§       Little is known about their lifespan, but it is unlikely that most live longer than 3 years.
§       One report says that they travel an average of 6.1 to 39.6 meters in a day.  Are there mini radio-collars to track these frogs?!
§       The Spring Peepers eat small insects and other arthropods including springtails.  But a number of things also will eat the peepers (snakes, larger frogs, fish, birds, etc.).  They are somewhat camouflaged so that probably helps to protect them.

Some references:

1 comment:

  1. These are interesting facts about peepers. I have found very little success in trying to actually see them singing -- I think they are ventriloquists, making their voices seem like they are coming from somewhere else. I suppose if that is true, that could help them avoid predators.