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Unit A: Section 1.2. Equilibrium Unbalanced. How many species of snakes are there in Alberta? A. 0 B. 4 C. 10 D. 20 How many species of true frogs occur in Alberta? A) 0 B) 3 C) 10 D) 30 http://www.daversitycode.com/.
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Unit A: Section 1.2 Equilibrium Unbalanced
How many species of snakes are there in Alberta? • A. 0 • B. 4 • C. 10 • D. 20 • How many species of true frogs occur in Alberta? • A) 0 • B) 3 • C) 10 • D) 30 • http://www.daversitycode.com/
Generations have had their idea of the animal world filtered through Disney. But has the magical kingdom been a force for good or ill in the *real* animal kingdom? • Do you think Telus or other advertisements (such as Coca-cola) with animals has had a impact on animal conservation?
Bald eagle population- Lake Erie • Common along shorelines (1700s-1800s) • Started decreasing in numbers in the 1900s due to farmers and toxic chemical waste • Made eggshell thin • Birth rate declined • First bald eagle born and raised took flight in 1983
The health of top level consumers like eagles indicates whether toxins are entering an ecosystem • If dynamic equilibrium is upset the health of many organisms is affected • If changes are large enough extinction may occur
At Risk Species • Endangered species • Close to extinction in all parts of the country or in significantly large areas • Extirpated species • No longer exists in one part of the country • Threatened species • Any species that is likely to become endangered if factors that make it vulnerable are not reversed • Special concern • Any species that is at risk because of low or declining numbers at the fringe of its range or in some restricted areas
At risk species Less severe risk Special concern – numbers are declining at the range / fringe of the area Threatened – species may become endangered if threatening conditions are not reversed Extirpated – a species no longer exists in one particular area, but is still found in other areas Endangered – a species is close to extinction in all parts of their natural habitat Extinct – a species no longer exists Most severe risk
The Disappearance of Frogs • http://www.youtube.com/watch?v=nYM3eWibvwU • Indicator species • A species sensitive to small changes in environmental conditions • Amphibians are important indicator species • Exposed to hazards in 2 different ecosystems (aquatic and terrestrial) • Fish, Algae, and Plants are also indicator species • What would happened to insect populations if the frog population decreased • Already occurring in Bangladesh due to the frog being a delicacy
Why are Frogs Disappearing • Amphibians have been around for 400+ million years • Even survived the dinosaur disaster • Biologists have become aware of the gradual disappearance of amphibians • Frogs, toads, and salamanders • ~30% of North America’s frogs/toads are in trouble!
Some probable causes • Loss of habitat • Growth of cities and human activities (farming/industry), highways, forestry • Air and water quality • Frog skin is think (lacks protection) • Pollutants can also pass through the thin moist skin (such as acid rain) • Acidity affects frogs ability to reproduce • Limits sperm mobility • Embryos grow slowly • Deformed limbs
Some probable causes • Climate change • Increasing global temperatures • No frog can stay in direct sunlight for too long or completely separate itself from fresh water • Ultraviolet radiation • The thin skin is susceptible to UV radiation (causes sun burns and cell damage) • Frogs that live in higher regions seem to be most vulnerable • Have developed adaptations • Black eggs • Black covering lining their organs
FOOD CHAINS • Herbivore • An animal that eats only plants • Carnivore • An animal that feeds only on other animals • Omnivore • An animal that eats both plants and other animals • Detritus • Waste from plants and animals, including their dead remains • Decomposer • An organism that feeds on detritus
