Disappearing Frogs - Research

Group Members:______

Date:______Class Period______

Using , students must answer the following questions:

Each question set is labeled with the name of the section in which it appears on the website.

Natural History:

  1. What are the two species that are considered mountain yellow-legged frogs?

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  1. What has this frog adapted to do that most other amphibians cannot?

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Distribution:

  1. In what two states do these frogs live? Where are they usually found?

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Life Cycle:

  1. How long does it take most frogs to develop from an egg to a tadpole and into a frog?

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  1. How long does it take the yellow-legged frog tadpoles to metamorphose (change) into frogs? Why does it take so long?

Ecosystem Role:

  1. When the frog is a tadpole, what do they eat? Are they carnivores, omnivores,or herbivores?

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  1. When the frog is an adult, what do they eat? Are they carnivores, omnivores, are herbivores?

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  1. Why is the mountain-yellow legged frog so important to their ecosystems? Explain.

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Current Status:

  1. Recent studies have shown that these frogs are now missing from _____% of their natural locations in the Sierra Nevada, and ______% are missing from their localities in the Transverse Ranges.

Threats:

  1. What is usually the main cause of amphibian losses around the world, but is likely only a minor factor in the loss of the yellow-legged frog?

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Disappearing Frogs (Continued)

Introduced fish:

  1. Why were the areas that the yellow-legged frog lived devoid of (missing) fish?

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  1. Where did the fish come from, and why were they added?

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  1. What evidence do we have that removing the trout would actually help the frogs?

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  1. Why are the trout such a problem for the frogs?

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  1. Why don’t the frogs grow in the small, shallow ponds without trout in them?

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Disease:

  1. What impact has the Chytrid fungus (chytridiomycosis) had on the frog populations?
  1. The last sentence in this section states: “Regardless of the mechanism, these persistent frog populations may well be the only hope for preventing the extinction of the mountain yellow-legged frog.”

Using what you know about natural selection, what do you think this means?

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Contaminants:

  1. What is the major contaminant affecting the yellow-legged frog populations? Where is it coming from?

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  1. Researchers are trying to determine if low concentrations of pesticides make frogs more vulnerable to what disease?

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UV Radiation:

  1. Why do researchers think that UV radiation is not a major factor in the decline of the yellow-legged frog?

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Conservation Efforts:

  1. What did the California Department of Fish and Game (CDFG) implement to help frog populations?

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