It seems as spring has officially sprung!
As you venture further into Irvine’s property, past the Vista Loop Trail, your ears will start to pick up on the faint sound of sleigh bells. Sleigh bells? That can’t be right! What you are actually hearing are thousands of tiny frogs! Spring Peepers are one of the first signs of spring – the Robins of the amphibian world.
Beginning in late March, as the snow melts and the days get warmer, Spring Peepers emerge from their hibernation and begin calling for mates. Once a male has established a territory, he will emit a loud peeping call. This call and competition for females is often done in a trio of frogs, with the lowest-pitched frog starting the chorus. The rapid succession of peeping, one peep every second, can be deafening during the height of the breeding season. While each frog makes a ‘peep,’ a large collection of males sounds like sleigh bells! They are so loud that they can be heard from over a half-mile away!
But how does such a tiny frog – a frog the size of a paperclip – make such a loud sound? A Spring Peeper’s vocal sac is almost the same size as their entire body! Males will pump the sacs with air (looking like a balloon) and then expel the air whilst letting out the loud peep. Due to the large sized air sac in proportion with the rest of their body, they can cause quite a ruckus!
Now imagine that you are a female Peeper…how do you ever choose which male to mate with?! Females first must pick out the males that they understand. All species of frog have a separate call that helps each species determine who is available. Even the same species of frog have different dialects! A Spring Peeper on one side of a road may have a different dialect that a Peeper on the other side. Once a female has determined which males are available, she often chooses the male with the fastest and loudest song.
After a mate has been chosen the males will externally fertilize the female’s 500 – 1500 eggs that she’ll lay in aquatic vegetation. Many “satellite males” will try to sneak in their sperm to fertilize her eggs, but the male she has chosen has the greatest success. The eggs will develop into tadpoles and eventually the tadpoles will metamorphosis into frogs to begin the process anew.
Scientists have been unable to determine the lifespan of wild Peepers, but captive ones can live to be 3-4 years old. What scientists have discovered is that these tiny frogs can do something amazing. Besides being able to chirp at such a loud and fast frequency, Spring Peepers are capable of freezing in the winter for hibernation and then thaw in the spring with no side-effects. They have a special component in their blood, similar to antifreeze, that allows them to cool down and freeze without actually killing themselves. This is not only helpful for the frogs, but is of interest to humans due to the potential ability to use the knowledge to help in the transportation of organ transplants.
While you may never see this tiny, well-camouflaged frog this spring, you will most definitely hear them and may one day have to thank them for saving your life!