Ecology

The Silence of the Frogs 30% of North American frogs are in trouble. An amphibian is an animal capable of living in both water and on land Frogs are important indicators of ecosystem problems because they are affected by 2 ecosystems (in the water and on land). Frogs are also much more sensitive to environmental changes.

Amphibians have been around for more than 400 million years Amphibians have been around for more than 400 million years. Surviving the dinosaurs! Frogs and their relatives have adapted to the ice age and global warming. They can be found in most ecosystems that include water. ECOSYSTEM – is a term used to describe the relationships among the many species living in an environment and the relationship among those organisms and the non-living components of the environment. Examples: Wetlands, marshes, deserts, lakes, oceans, forests.

WHY ARE FROGS DISAPPEARING?

1. LOSS OF HABITAT Habitat is the place where the species live. This is mentioned as the main cause We are destroying the water with pollution. Frogs need water to lay eggs. We are cutting down forests. This exposes frogs to predators. We are building highways and cities between the two ecosystems.

2. AIR AND WATER QUALITY Frogs have a thin skin, this makes them more susceptible to pollutants. Frogs breathe through their skin and by lungs. Acid rain therefore can go through their skin. This acidity reduces their ability to reproduce Embryos develop poorly in acidic water.

3. ULTRAVIOLET RADIATION Our damage to the OZONE layer is allowing increased levels of UV radiation.The thin skin is susceptible to UV radiation. Frogs have adapted by developing a black skin and laying black eggs. Scientists don’t believe that frogs will adapt as fast as global warming.

4. CLIMATE CHANGES Humans are burning fossil fuels (coal, oil, gas) causing global temperatures to increase. Climate changes affect the local ecosystems. Wetlands dry up and frogs are unable to reproduce. Scientists don’t believe that frogs will adapt as fast as global warming.

Why are Scientists Concerned Many believe that the health of amphibians indicates the health of the ecosystem they live in. Frogs are bioindicators of the health of the earth. Amphi ( “on both sides”) Bios ( “life” ) Meaning that Frogs have two lifes – water and land

Frogs occupy two different ecosystems Tadpoles – water ecosystem Adult Frogs – Land and Forest Since they are in two ecosystems, they are also in two FOOD CHAINS. FOOD CHAIN – Is a step-by-step sequence linking organisms that feed on each other, starting with a food source such as a plants (producers), and continuing with animals and other living things that feed on plants and on each other (consumers)

Food Chains

All food Chains start with Sun as it’s source of energy! PRODUCER – an organism that can make their own food to give themselves energy. EXAMPLE: Plants, algae CONSUMERS: an organism that must get its energy by eating another organism ( cannot make their own food ) EXAMPLE: animals

FROGS IN THEIR ECOSYSTEMS What do adult frogs eat? Insects ( mostly ) Small fish ( limited ) What animals eat frogs? Large fish Predatory birds Reptiles Small mammals

The adult frog is part of a food chain that includes PRODUCERS, HERBIVORES , CARNIVORES , OMNIVORES. HERBIVORE – Organism that eat only plants EXAMPLE : Deer, Cow CARNIVORE – Organism that eats only animals EXAMPLE : Hawk, Tiger

OMNIVORE : Organism that eats both plants and animals. EXAMPLE: Bears, Humans What do tadpoles eat? Algae ( small plant-like organisms) Both living and dead

The Tadpole is a herbivore, where the adult frog is a carnivore The Tadpole is a herbivore, where the adult frog is a carnivore. Therefore the Tadpole is in a different food chain. The Tadpole has two food sources: 1. producers ( algae ) 2. Detritus DETRITUS – Waste from plants and animals, including their dead remains

Detritus food chains are critical in the recycling of matter in ecosystems. Decomposers are in a Detritus food chain which helps release nutrients to the soil and water. Plants and algae use those nutrients to grow. DECOMPOSERS – An organism that gets its energy by consuming and breaking down detritus. EXAMPLES: Bacteria, fungus

PLEASE ANSWER QUESTIONS PAGE 13 - #2,3 Page 11 will help you with answers.