Millions of years of evolution have endowed frogs with amazing attributes and abilities that enable them to successfully straddle two realms.

Over the past 250 million years, frogs have spread to almost every corner of the world—outliving the dinosaurs and surviving ice ages and meteorite impacts. Their success is due not only to their superb hunting skills, but also to the fact that their habitat is not limited by water or land…

The sun has just set, and down at the pond things are still relatively quiet. Then a voice calls out from the reeds, and the first “ribbit” is quickly joined by an entire enthusiastic choir. There will be no peace at the pond tonight…

Though an army of frogs croaking may sound disorganized, there is, in fact, a system. Each frog has its own “ribbit” that’s unmistakable to other members of its species. One of the main purposes of male croaking—in addition to establishing the territory of an individual—is to attract a female.

With such a sense of purpose, it’s no wonder a pond full of frogs can croak at deafening levels. The coqui frog can produce almost 100 decibels of sound at a distance of 20 inches. The “co” and the “qui” serve two different purposes: The “co” is a territorial call to warn other males, and the “qui” is intended to lure females for mating.

LIVING LEGEND

Some people would rather not hold a frog, but many find them appealing. Perhaps deep in our genes we sense that we owe them a debt of gratitude. Fossil records indicate that they made the transition from water to land some 250 million years ago. If it weren’t for this pioneering evolutionary effort, we might still have gills and a tail and be confined to living in murky waters ourselves. Frogs can be found in and around most bodies of fresh water on every continent except Antarctica.

There’s a species of wood frog (Rana sylvatica) with a range extending from the U.S. state of Georgia to Canada and up into the Arctic Circle, that can freeze, thaw out, and continue to live. Telmatobius macrostomus (the Andes smooth frog) is found at altitudes of up to 14,000 feet in the mountains of central Peru, and the Sahara frog is found across North Africa from the Western Sahara to Egypt.

You’d think frogs need incredibly strong leg muscles to jump the way they do. However, research with a high-speed camera has shown that the secret lies in their tendons. They use their muscles to stretch their leg tendons as far as possible before a jump. When the tendons recoil, the spring action propels the frog up to 50 times its body length. Compared with frogs we’re doing it backwards, which may explain why we can’t leap hundreds of feet in a single bound.

CROWN OF CREATION Frogs come from a proud lineage. The oldest known frog fossil is from a creature that lived in what is now Madagascar during the Early Triassic Period, about 250 million years ago. It probably spent at least part of its life on land and could breathe air. Today there are more than 4,800 known species of frogs. While some are as tiny as a third of an inch, the Goliath frog can grow to a length of more than a foot and weigh more than 7 pounds.

WHY STOP AT ONE? A frog seldom comes alone—and that applies especially to the common frog (Rana temporaria), which is native to Europe and Asia. One reason is the species’ incredible fertility: The female deposits a large clump of eggs that may be up to 4,500 strong. The eggs are surrounded by a gelatinous mass that in addition to providing protection also works like a magnifying glass to increase the sun’s warmth, helping the eggs hatch. LITTLE MIRACLES IN THE POND Frog larvae are called tadpoles. Among their remarkable qualities is their ability to regrow a tail or lost limb with the help of a gene that’s no longer present in warm-blooded animals.

HOW DOES A FROG WIN THE HEART OF HIS BELOVED? What ignites passion in a female frog? Two things, for starters: the male’s powerful voice and his shiny green skin. An obstacle to love at first sight: Frogs will change color depending on their location. It takes direct sunlight to turn a male the glossy green that the ladies love.

ALL-SEEING EYES Frogs’ bulging eyes give them a panoramic, almost 360-degree view. When they’re in the water they’ll use their eyes like a periscope and keep their body hidden under the surface. Frog eyes come in an astonishing range of colors. Researchers have discovered that the coloration is, in part, a protective measure: Potential predators are often distracted just long enough for the frog to leap to safety.

BETWEEN TWO WORLDS How long a frog will spend as a tadpole depends on the species. While many make the transition in about 12 weeks, bullfrogs can take more than a year. Environmental factors such as water temperature and the degree of crowding also play an important role.

GIVE ME A BREAK! Producing multiple “ribbits” per second for hours on end takes a lot of energy when the sound can be as loud as 90 decibels (almost as noisy as a motorcycle engine). Generally it is the males that make the calls, in the hope the females are listening: Frogs’ ears are called tympana and are located behind the eyes, resembling flat circles. Frog ears are essentially tuned to hear the calls made by members of their own species.

AVOID THE BURN As amphibians, frogs are cold-blooded animals: They don’t produce their own body heat or have mechanisms such as sweating to cool off. Thus they will change locations throughout the day to maintain a relatively constant temperature, staying in the sun to warm up and heading off to the water to cool down.

Climbing affords tree frogs a better view. In addition to having panoramic vision, frogs are able to see better at night than any other animal and can perceive color in darkness so extreme that we would be unable to see anything at all. Color vision is useful when searching for a mate or hunting for food. SOCIAL CLIMBERS