Toad-ally Frogs

Tim Iverson
Seasonal Naturalist
Cunningham Falls State Park

(9/2012) For a moment let’s step back in time. We’ll go back to the good ol’ days. We’re going to rewind to a time past when Glenn Miller played the songs that made the hit parade. Even before anyone had a LaSalle than ran great…or at all. No, no we’re going way way beyond any of that. We’re going to just skip right over the Renaissance. We’ll leap straight over the Iron, Bronze, and Stone ages. Just keep on trucking all the way back to about 190 million years ago. Imagine yourself very much in a Jurassic Park like setting where you’re standing in a field or a forest marveling at the giant reptiles meandering about you. Thundering steps and deafening roars of immense dinosaurs have your full attention. In fact, you’re probably so caught up in the awe-inspiring sight you don’t even notice what’s hopping around right at your feet. It’s a frog! That’s right frogs have been around since at least 190 million years ago and coexisted with the dinosaurs. Alright, now we can fast-forward back to the present.

Frogs and toads often get confused for one another, and if you’ve ever been called something you’re not you might bear some resentment over it. For toads and frogs there are some differences. For starters frogs must live near water, whereas toads do not. Frogs usually have smooth and moist skin, while toads have dry and bumpy skin. Frogs tend to have more predators than toads. Toads are fatter, lower to the ground, have shorter legs, and don’t hop as well as frogs. The most important thing to remember though is that neither one can give you warts, that’s a myth.

Frogs are amphibians, which mean they can live on both land and in the water. It’s a pretty good deal for them because they get the best of both worlds. If a situation gets too dicey up top on the land and it looks like they might become a snack they can retreat to the protection of a pond. Or if there isn’t enough grub in the water then they can try their luck topside. The habitat for frogs can be pretty varied too. They’re found on every continent except Antarctica, which means they range from barren deserts to the frigid arctic. The Wood Frog (which is native to Maryland) survives for months at a time frozen solid! The glucose in its blood essentially acts as anti-freeze and will surround vital organs while the rest of the frog remains frozen solid. Then when warmer temperatures return in the spring it thaws out and keeps on hopping. Frogs have even more physical adaptations that make them impressive.

Frogs have legs that would make Olympians jealous. If there were inter-species Olympics frogs would get the gold in the long jump every time. Most can actually leap up to 20 times their body length, while some can get up to 50 times! So to put that into perspective, the average person would be able to jump up to or more than 100 feet! The longest recorded frog jump measures in at 33 feet and 5 ½ inches. The record was made by a frog named Santjie at a frog derby in South Africa. Their feet are nothing to balk at either. Depending on the type of frog that they are the characteristics of the feet will differ. Aquatic frogs have webbed rear feet that help them move efficiently and gracefully through the water. Tree frogs have large round toe pads that essentially work like suction cups that help them climb. Meanwhile, land frogs have short stubby legs that work best for walking and climbing.

The skin of a frog is enough to make your skin crawl though. Frog skin is a remarkable feature that truly stands out in the animal kingdom. Frogs actually breathe through their skin, which is really helpful if you’re an aquatic frog! Frogs must keep their skin moist; otherwise they can’t absorb oxygen and will suffocate. They don’t just breathe through their skin though, they drink too! By absorbing water through their skin frogs really cut down on straw expenditures. The skin is also a snack too! Just like any other reptile they’ll shed their skin about once a week, and then they eat it. If times are tough they’ll always have that reliable meal.

That’s not all frogs eat though. Frogs will eat just about any insect that can find, and even some very small fish too! Frogs will roll out that very sticky tongue to catch prey and pull it back. They do that all in about one second. They essentially do that whole process blindfolded too! Frogs close their eyes while the tongue shoots out, and then use their eyes to help swallow too. Frogs can retract their eyes by sinking them into their skull to help force food down their throat.

Now frogs aren’t usually thought of as the biggest or baddest guy on the block, but they can hold their own alright. Coloration plays a huge role in frog defenses. Most use color as camouflage in order to better hide themselves, while other use really bright colors to stand out. The latter kind that uses bright colors is telling potential predators not to eat them because they are very poisonous. Now most frogs have poison, but some are stronger than others. It’s usually only released when their threatened, like being eaten for example. And when all else fails sometimes they’ll just play dead.

Birds chirp, dogs bark, and frogs croak. The croaking is used by males to attract females. The coolest thing about this is that frogs can only hear the sounds of their own species! Croaking begins the birds and the bees so the life cycle can continue on for the species. Once a male and female consummate their relationship, which in the frog world is called "amplexus", the female will lay the eggs and leave them entirely on their own. The eggs will hatch in a matter of days or weeks depending on the species. Once they hatch they become tadpoles and then will eventually drop their tails, grow some legs, and become frogs.

Miners used canaries in mines to detect toxic levels of gas or air conditions. Birds were more sensitive to this, so if it dropped dead it was time to hightail it out of there. Scientists see frogs very much the same way. Frogs are considered an indicator species because they are sensitive to changes in the ecosystem. Worldwide frog population densities are decreasing and we’re facing rising species extinction rates too. In Yosemite National Park three out of seven native species are gone. Like the canary in a coal mine idea, the same notion is applied to frogs. If conditions are unfavorable to them soon they may be unfavorable for us. The causes for the population declines can be a regional or isolated local event like habitat loss due to deforestation or development. Other attributable causes though are rising global temperatures, and thinning ozone layers. Since frogs both breathe and drink through their skin they are especially susceptible to acid rain and pollution in the water supply.

As incredible a critter as frogs are with their serious skin, romantic dispositions, eye-popping eating techniques, and the rest they are truly an integral part of our environment. Their symphony and chorus ringing through the summer’s night brings nostalgic moments for many people. No matter what the cause for decline people should pay special attention to this indicator species. Through careful research and conservation we may be able to hear their nightly symphony for another 190 million years.