Tropical rainforests are the most important type of ecosystem in the world because more than half of all species of plants and animals are found there.  The reason for this incredible species diversity is that conditions for plant growth are ideal with warm weather year round and plenty of rainfall.  Unfortunately, we are destroying tropical rainforests at an alarming rate.  At the rate we are going the rainforest ecosystems will be gone within the next 100 years resulting in the most catastrophic mass extinction since the dinosaurs were wiped out 65 million years ago!  Human destruction of natural habitat in rainforests and other ecosystems is the number one cause of extinction around the world.  Global warming has the potential to be an even bigger cause of extinction than habitat destruction in the future.  Other causes of extinction include introduced species, hunting , and poaching.

Because of the thick plant growth and tall trees, most of the habitat in the tropical rainforest is above the ground and most animals can be found in the trees.  The Green Iguana lives in the tropical rainforests of South and Central America.  It is an example of an animal adapted for living in the trees.  Its color gives it good camouflage.  Its legs and feet are adapted for climbing.  The legs are long and the fingers are extremely long with long sharp claws at the end.  This is so that the iguana can grip tightly to the tree.  The back legs point out and back instead of forward.  This is an adaptation for gripping the tree as the iguana climbs down.  

The Green Iguana is an herbivore.  Its teeth and digestive system are adapted for eating tender leaves of the trees it lives in.  The most unique and amazing adaptation of the Green Iguana is a light sensitive scale on top of its head that acts as a “third eye”.  It senses daylight and darkness and sets the Iguana’s biological clock.  The iguana is only active during the day and loves to bask in the sun.   

People in South America refer to Green Iguanas as “Chicken of the Tree” and they are commonly hunted for their meat.  While iguanas are not endangered, many animals around the world are because humans kill them for the value of their meat, skin or other body parts.  Examples are the Black Rhinoceros whose horn is used in Chinese medicine and African Elephants that are killed for their tusks.   Many species have already become extinct and many more will become extinct in the future because of hunting and poaching.

The Common Boa Constrictor is also from the tropical rainforests of South and Central America.  Its color gives it camouflage on the forest floor.  Constrictors kill their prey by capturing it with their mouth, coiling around it and squeezing it to death, then swallowing it whole.  All snakes are carnivores.  Most snakes are ambush predators that sit still waiting for prey to come close enough for them to strike and capture.  

Boas belong to a family of snakes that include the Pythons and Anacondas.  The Green Anaconda is the world’s largest snake with some individuals getting over 30 feet long and as big around as an adult human!  My Boa is 11 feet long and weighs 35 pounds.  All members of this family of snakes have a pair of tiny bones near their tail that are left over from the leg bones of the lizard ancestors that snakes evolved from beginning about 100 million years ago.  Structures like these that are left over from evolution are called vestiges or vestigial structures. 

Tropical Savannas and grasslands are ecosystems that are warm year around but have limited rainfall.  All of the rain comes during a short rainy season and the dry season can last for 10 months with no rainfall at all!   Plants here are limited to grasses and a few scattered scrubby trees.  This is the ecosystem found in West Africa where the Savannah Monitor lives.  This monitor lizard shares its territory with the lions, giraffes, zebras, and elephants we are so familiar with.   

Like the tropical rainforests, grassland ecosystems are also being destroyed by humans at an alarming rate.  Grasslands are used to graze cattle and too much grazing can turn them into deserts.  Scientists call this “desertification”.  In the past 50 years, the Sahara Desert in Africa has expanded by hundreds of miles because of the desertification of grasslands. The plants and animals from the savannah must be adapted to survive through the long dry season with very little water available.  

The Savannah Monitor burrows into the ground to survive.  This protects it from the heat and the dry conditions as well as providing a place to escape from predators.  Its camouflage blends in with the color of the dirt.  It has short legs and short strong fingers for digging.  Its body is very flexible so that is can move around in the tight space of its underground burrow.  When it gets extremely dry the Savannah Monitor become inactive kind of like the hibernation that reptiles around here do in the winter.  

Monitors have a tongue just like snakes that they use to help them with their sense of smell.  They sample the air with their tongue and transfer it to a special organ for smell in the roof of their mouth.  The forked tongue tells them which direction the smell is coming from in the same way that having two ears tells us the direction a sound comes from.  Some scientists think that the monitor lizards and snakes evolved from the same ancestor since they have the same type of tongue. 

The desert ecosystems are the driest of all.  Plants and animals have to be adapted to living in an extremely dry environment.  The Bearded Dragon is a lizard from Australia that is adapted for living in the desert.  Its light color gives it camouflage in the sandy soil and reflects the heat of the sun.   A captive Bearded Dragon must a have place to bask that is over 100 degrees and it will rarely move from that spot!  The flat body of the Bearded Dragon makes it easy for it to burrow under the sand to escape from the heat and from its predators.  

There is very litte food and water available for animals living in the desert.  Reptiles are common in desert ecosystems because they can get by without much food or water.  Reptiles are cold blooded so they don't use energy to regulate their body temperature and they don't need nearly as much food as warm blooded animals.  

Reptiles don't need as much water because their kidneys conserve water by making a waste product that has very little water in it.  This is the white stuff you see in bird and reptile poop!  It is called uric acid.  The waste from our kidneys is called urine and it is 95% water.  You would die of kidney failure in just a few days with no water but desert reptiles can go for a long time without water.  In fact, the Bearded Dragon does not drink water.  It gets all the water it needs from the insects and plants that it eats.  

The type of ecosystem found in our area is the temperate deciduous forest.  Temperate ecosystems are in between the warm tropics and cold artic regions.  They have hot and cold seasons.  The deciduous trees shed their leaves and go dormant as an adaptation to the short winter days and cold weather.  Reptiles have a similar adaptation called hibernation.  During the winter they find a sheltered place where they will not freeze then they go dormant for five or six months.  

The Eastern Garter Snake is one of the most common snakes found around people.  It looks like the garters that men used to wear around their ankles to hold their socks up.  These hardy snakes can be found as far north as Hudson Bay in Canada!  Most reptiles lay soft eggs and do not protect their eggs.  Garter snakes along with Copperheads, Rattlesnakes, and a few others carry their young and give live birth.  By doing this they can keep the babies warm by warming up their bodies in the sun.  The babies develop more quickly and are born sooner than babies of egg laying snakes.  The babies can even develop in cool weather, so this is an adaptation to living in a temperate ecosystem.  

The Black Rat Snake and the Black King Snake are also common around people because they find prey in buildings and houses.  They are harmless and very good to have around because they eat mice and rats.  Black Rat Snakes can get almost seven feet long!  King Snakes eat lizards and other snakes as well as rodents.  They can even kill Copperheads and Rattlesnakes because they have developed immunity to the venom of these snakes as an adaptation for being a predator of them.  

These two black snakes along with several other black and dark colored snakes found in our area have compromised their camouflage to help them survive our temperate climate.  Dark color absorbs heat better than lighter colors allowing these snakes to warm up in the sun more efficiently.  They spend less time hibernating and more time active.  This helps them to survive because they can grow faster and produce more offspring.  

The Eastern Box Turtle is the only land turtle found in our area.  It has a tough shell made of bone that it can close itself in to thanks to a hinged bottom part that acts like a door.  Its feet are adapted for walking and digging.  The shell of the softshell turtle is made up of a leathery skin with less protective bone than most turtles.  Its shell is adapted for its shape instead of for protection.   The streamlined shape of this turtle allows it to move through the water more quickly and with less friction.  Its feet are webbed for swimming and it has claws for digging. Its long neck and pointed nose allow it to bury itself under gravel or sand and come up for air without coming out of hiding.  Only the long neck and head comes out.  The turtle can stay buried.  Because of this adaptation, the Softshell Turtle must have an aquatic ecosystem that includes shallow water with a soft bottom of sand or loose gravel.

The Alligator Snapping Turtle is an aquatic turtle that is adapted for living on the bottom.  It has powerful legs and long sharp claws for digging.  Its long tail can wrap around things to hold on.  The Alligator Snapper is different than the Common Snapping Turtle that is found in local streams and ponds.   While the Common Snapper tops out at over 50 pounds,  Alligator Snappers can exceed 200 pounds, making them the largest fresh water turtles in North America.   Another difference between the two turtles is the worm-like tongue that the Alligator Snapper uses to lure fish.  It sits stone still on the bottom with its mouth wide open and wiggles its tongue making it look just like a worm.  When a fish comes close enough it strikes with its powerful jaws.

All amphibians are aquatic at some point in their lives because their eggs are laid in the water and they hatch out as larva that have gills.  Frogs and toads start as tadpoles that go through metamorphosis and change into adults.  Salamanders have a similar life cycle with larvae that have gills that can be seen on the outside of the body.  

The African Clawed Frog is totally aquatic.  Its webbed feet are adapted for swimming, not hopping on land.  Its body is extremely slimy with mucous that helps protect its skin in the water.   Its eyes are smaller than other frogs and are designed to be able to see in the water like the eyes of fish.  Because their skin is not waterproof, amphibians are vulnerable to pollution.  When water becomes polluted they are the first to be harmed.  This makes them important animals for scientists studying pollution.  African Clawed Frogs are used in experiments to see how harmful certain chemicals are in water pollution.

The Bullfrog is the largest frog in North America.  It is semi-aquatic.  Its spends most of it time on land near the edge of a lake or stream waiting for prey to come close enough for it to leap out and gulp down.  It must jump in the water occasionally to keep from drying out and it will leap into the water to escape predators.  Its feet are adapted for swimming and hopping.  They are webbed but they also have bumps on the fingers that are used for gripping the ground.  

Humans have introduced African Clawed Frogs and Bullfrogs into ecosystems where they do not belong.  Thousands of species of plants and animals have been introduced both accidentally and intentionally making introduced species are the second leading cause of extinction worldwide behind destruction of habitat.  This problem continues to get worse with the increase in global trade since plants and animals “hitch-hike” in shipments.  Bullfrogs are endangering native frogs where they have been introduced because frogs are a big part of their diet.

The American Toad is our most common native toad.  Adult toads are not aquatic.  Their feet have no webbing and their skin does not dry out as easily as the skin of frogs.  Toads survive on land by carrying extra water inside their bodies and by being able to soak up water through their skin from damp soil.  They mainly eat insects that they catch with their long sticky tongues.