Paradigm Shift

Observe and Infer

The Silence of the Frogs Goal: to understand how frogs make a good indicator species.

Frogs K W L

Frogs- A History Been around for 400 million years Survived global extinction 250 million years ago (most plant/ animal life) and 64 million years ago (dinosaurs) Adapted to ice age Global Warming (periods) Withstand drought, flood, winter Found in most ecosystems that have water

Frog populations

Stop and think! From our KWL chart, what could be happening to frogs that are causing their populations to crash when they have survived for millions of years. Video

Why are scientists concerned? Summarize the main points from the video. Great indicator species because: Live in two ecosystems (tadpoles/ water) (frog/ forest and grasslands) Exposed to hazards in both ecosystems Two different food chains

Vocab- match herbivore, carnivore, omnivore producers, consumers

Frogs wiped out- What next ? Tadpole food chain Frog food chain How would it effect the rest food chain ?

Human Impact Bangladesh Frog populations wiped out for restaurants Mosquitos increased Mosquitos carrying malaria increased (blood transmitted disease) More human infected with and died from malaria

Why are frogs disappearing? Loss of habitat Habitat ‘cut off’ between ponds and woods (roads) Tree cutting= exposing to predators Pollution Frog skin is thin Have lungs but also breath through their skin Pollutants can pass through too Acidic water – reduces chances of eggs being fertilized Slows down embryo development, deformed limbs etc

Exit slip- Check for Understanding Explain why the life cycle and skin of a frog make it a good indicator species if you want to determine the health of a local ecosystem. Construct a concept map that links the decline in the number of frogs to factors that may cause the decline. Choose one of the possible causes and using your own words, explain how it affects frogs. Are there any other organisms that would make a good indicator species? Explain. Frog Declining