Since the dawn of time, the life cycle of the animal kingdom has fascinated people of all ages. The same people that followed the neighborhood cat around, waiting for a litter of kittens to appear are now paleontologists, researching the earliest animal life cycles we know of – dinosaurs. From childhood to far into the golden years of our lives, we will always be interested in the way the world works, and one of the first life cycles we learn and understand is that of the frog.
Just when you thought it was safe to sit outside on a warm night or open your window a crack to let a sweet breeze blow through the room, you’re interrupted by the sound of froggy hanky-panky. Beware! It’s mating season, and frogs don’t care how loud they are or how long they’ve been courting their prospective mate – this is a part of the life cycle that we will just have to live with. Frogs actually use a variety of ways to attract a mate including those courtship calls, as well as body color and limb movements.
Now let’s get one thing straight, a frog will try to mate with anything that moves, so your frogs could make several attempts before actually finding another frog. Plus, frogs have just as tough of a time as people when it comes to judging the sex of one another, so you may hear a very angry frog sound if two males end up together – that’s their way of warning each other. Once a male does find a female, the process is fairly easy. The male will climb on the female’s back and reach his arms around her midsection, or sometimes even her head. This grasp is called amplexus and in this position, the male fertilizes the eggs as they are laid. This can last several days, and the frog’s spiny, black nuptial pads make it easier for them to get a grasp on the females, just in case she tries to escape.
Most frogs lay their eggs in water and the thousands of eggs are usually found in large slimy masses called clutches. To avoid a rough and tumble beginning, the eggs are usually laid in calm or static waters. The eggs themselves look like little balls of jelly.
Once the eggs are laid and fertilized, they have a rough road to travel before developing into a full-fledged frog. The reason so many eggs are laid is that many don’t survive. There are many hazards between the spawning and hatching processes. Some die naturally (they tend to turn white or opaque) and predators like koi and water spiders gobble up many frog eggs too. If they do survive, it usually takes about 6 to 21 days for them to hatch, depending on the conditions.
The eggs hatch into tadpoles – still far from the form of an adult frog. They live in water, breathe using gills, and have a long tail instead of arms and legs. Tadpoles also have a small mouth for scraping algae off the bottom of the pond, however they will continue to feed on the remaining yolk left in its stomach. Their best bet at survival is to use the sticky organs between the belly and mouth to attach themselves to floating plants or grasses. Seven to 10 days after hatching, the tadpole will begin to swim around and feed on algae.
The process of a tadpole growing and evolving into a full-grown frog is called metamorphosis, and it’s fascinating. Only about four weeks after hatching, the gills start disappearing and little teeth used to grate food begin to form. Two to five weeks after that, little legs begin to sprout and the head becomes a little more distinct. Soon, arms will sprout out, elbows first, but the tail remains. Dead insects and plants will quickly become a part of their diet as they continue to grow.
After about 12 weeks of growth, the baby frog is called a froglet, looking like a tiny frog with a small tail stub. Between 12 and 16 weeks, depending on climate, water and food supply, the frog will complete the life cycle. From there, they will start the whole process again, finding mates and laying or fertilizing their own eggs!
So, what does this mean to you? Well, we’re hoping that with your newfound appreciation of frogs, you might think twice before trying to get them out of your water garden. According to the National Wildlife Federation (www.nwf.org), certain species of frogs are declining due to droughts, pesticides, and other environmental problems. In fact, over 200 amphibian species from around the world have experienced recent population declines. Some species of frog have not been seen in over 50 years, while others have stopped mating, which could lead to extinction.
Make a difference and leave the frogs and eggs in your water garden where they are or create a nice upper pool, where tadpoles can have a chance a chance to grow and survive. Mother Nature will thank you for it!